QRP HF Ham Radio Transceiver/Kits SSB/CW


New page adapted also for mobile use, with an
--> updated QRP transceivers and kits table. SDR qrp transceivers and kits will be shown separately.

This site has had hundreds of thousands of visitors over the years it has been online. Work is underway to further develop user interaction and in the content there will also be a qualitative focus on information about development, construction and building of, above all, radio-related electronics, which is part of many visitors' interest.

Getting to know about ham radio, which is about

Elecraft® KX3 SSB CW transceiver

Elecraft� KX3 (QRP) SDR SSB/CW/DATA/AM/FM transceiver. It can now be ordered at Elecraft's order page.

For those unfamiliar with qrp radio, it's within ham radio and about electronics and physics. About radio waves, sound, antennas and more. It's a hobby related to communications, technology and science and it can also be about building and establishing friendships locally, regionally and even worldwide. That latter is maybe one of the most prominent trademarks of ham radio, or amateur radio.
The more common type of two way radios use higher radio frequencies that work locally with distance limits, where ham radio's lower frequencies may "skip" and bounce long distances on layers in the atmosphere. Qrp transceivers use lower transmitting power and some transceivers also require less power during reception too, so it is more suitable for portable use, where batteries or other (charging) power sources (as with solar cells) can last better and/or longer. Probably, that fascination for long distance communications got less when internet came. However, internet has cost billions of dollars and its infrastructures that work behind the scenes can or could be fragile.

Basic information:
About amateur/ham radio - wikipedia
What is Ham Radio? - arrl.org

About QRP radio - wikipedia
QRP: More Than a State of Mind - arrl.org
QRP -- Low Power Operating - arrl.org
QRP power - arrl.org

I thought I would ask if you could share this page here and there. To inspire others. It's fun to build things, and electronics can be built. Building small radios and then use them. For those who don't have any licence yet, the receiver can be listened to, doing CW listening practise too. It feels good to have built things on your own and you can do some modifications, an audio tone control, a RIT (+/- 1-2 kHz tuning at receiving only), an AGC time control or anything. A cool blue led at power-on.

So, a QRP transceiver is

A QRP transceiver is somewhat different than an ordinary transceiver. Smaller and portable, power typically 5W or less but some are a little above. Some are designed for CW, some for SSB and a few for both. Many qrp rigs have one band only, although in recent years there are more dual band and multi band transceivers. As for kits, more experience is achieved during the building and calibration. On this page you get an overview of known qrp transceivers and kits.

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Just some word about headphones

Below on this page is written about the importance of AGC when or if headphones are used. Headphones can improve the overall perception of selectivity because headphones can have a wider or flatter frequency range so you will here more compared to a little speaker. And of course, they can be used for other purposes as well.

Besides this page, here is a QRP forum you can look up:
QRP - eham.net

QRP sdr transceivers

Sdr transceivers have earlier depended on a pc all the time, which is not so portable. However last year the first qrp sdr transceiver without an always need for pc, SDR Cube, was introduced by Midnight Design Solutions, where one of the designers is also behind the Juma qrp transceivers. Then earlier this year, Elecraft� presented the KX3, an all band qrp sdr transceiver, also this one without an always need for pc. So we can expect that more transceivers of this type will be available soon.

Why QRP?

Many radio amateurs have had a general interest for radio and shortwave in particular. Earlier, and still in some countries, the entry classes only permitted low power, like 10w. With that low power, more efforts can be taken to have a better antenna.
Other amateurs, like me, started with cb which typically is 5 watts or less, just like QRP. In August 1979 I started with cb for real, after buying my first mobile radio, the cheapest new I found, and I made an own aluminium antenna. A little later I bought a gp-antenna. Already the year before, in 78, or maybe in 77, I heard a lot of traffic from france on my cb walkie talkie, and soon I found out that low power skip was actually possible.

Elecraft® KX3 SSB CW transceiver

The first radio a had. August 1979. First time I had a talk with someone in the US from where I was, in Sweden, was in the spring of 1980. 3.5 watts on AM.

A few watts did it!

Then with my mobile AM cb-radio with just a couple of watts, I soon tried to see if I could skip with this low power, just like a qrp-er. After some time I also made overseas contacts. After a year I bought a 3-element yagi antenna and then an SSB radio too. One year after that, around summer 1981, I decided to get an amateur radio license. I wanted to work on the HF bands so I had to learn CW reception. I could somewhat already "send" cw, but not hear. I had the cw-learning cassettes for two years already and some months or about 100 hours later, I thought I could it somewhat well and after some time I applied for an amateur license. Eventually, on the 4th of January 1982 I made a phone call to ask if I had passed the tests. The lady I talked to said yes you did, and you'll get your papers tomorrow. So can I start now I asked. Yes you can she said!

A qrp transceivers/kits page?

QRP radio is a fun part of ham radio and I since I did start as a qrper once in the late 70s, however on the cb-band, using only 3W AM even for dx qsos, I thought it was "cool"! And I stll think it is. So, I was looking around to find out about qrp transceivers but I did not find any page that covered what's available. So, like many others who have looked for that certain page and didn't find it, I thought I should do such a page. This is the only sofar, at least first internet page that covers this. So, close to all known QRP transceiver/radio kits are to be mentioned on this page with various shown resources.

QRP is SSB too, and there are a couple of transceivers capable of CW and/or SSB as well.

QRP, sunspots and radio propagations

One thing to remember, as the radio propagations are now getting better in the next years, the values of large signal capability, IMD etc have to be more considered, especially for the lower bands, 80, 40 and 20. On the quieter 30, 17, 12 and 10 meter bands, this is less or not critical.
Many "field"-reviews of qrp transceivers from the last up to about 7 years were in times of low sunspots. Earlier reviews from the last sunspot maximum may reflect these critical characteristics better, however some of the qrp transceiver kits back then that are still available, may have been improved. We do not know yet what the next maximum will be like so if you want to be on the safe side, find out about the large signal caracteristics. Top Notch Transceivers usually handle that well but they cost a lot more, and they're not portable. Some qrp band transceivers are sometimes even getting better rankings in some respects than most standard HF-rigs.

Improve audibility of transmitted audio - SSB

After all, most transmit with a power of 100 watts and qrp stations will then, on average, sound weaker. So what to do then? The first answer is given, by increasing the output power. But then it is not QRP anymore. So what can you do?

Phoneme significance vs spectral distribution

In a way, actually amplifying certain higher frequencies and thus lowering at lower frequencies. There are probably some readers who already understand what it is about. For a satisfactory speech perception and thus, intelligibility, to be possible, or rather sufficient, in a hf ham radio context, phonemes which on average have more significant speech information need to be amplified, which is done by amplifying the level of spectral areas that these phonemes have, which means that these frequencies are amplified. In accordance with this, the level for spectral areas with less phonological significance, low frequencies, can be lowered. This is because speech sounds must not only be detectable to be perceived and thus understood. They also need to be able to discriminate, that is, be able to hear a difference in, so that it becomes clear, in order for the heard speech in the sound to be decoded. This is also exactly what is relevant within hearing impairment and for the importance of properly adjusted hearing aids. There is another circumstance that explains why, after all, people with hearing loss sometimes can perceive what others say (besides the help of lip reading, which is not possible via radio), and, how hams can perceive speech quite well on the shortwave bands even when there is noise, qrm and so on. It is written about on this page, phonological memory in speech perception. I hope you find this interesting and if you do, please share this page!

Since it is usually the higher frequencies in the phonologically significant range (~ 0.5 - 3KHz) of speech sounds that are affected by hearing impairment, there is some similarity to the auditory characteristics found in a regular SSB receiver where there is usually an upper limit in the frequency range at around 2.2 - 2.8KHz. It corresponds roughly to what can be found in a moderate hearing impairment where there is often a difficulty in hearing consonants in the speech. Consonant discrimination, and thus decoding/intelligibility, differs from vowels among other things in that consonants are generally shorter than vowels and therefore consonants are more sensitive to interference. Consonants also have the energy more at higher frequencies, so a limited frequency range has a direct negative impact on consonants.
Since speech perception in an SSB radio receiver is affected by a more or less limited frequency range, where noise and interference is mixed with signals which sometimes are weak, it can be somewhat compared to how people with hearing loss can experience everyday environments. It could be possible to compensate this by simply amplifying the level of frequencies around 2 - 2.5/3KHz and also to lower the level slightly for frequencies below 500-750Hz. Another reason for lifting the 2-3KHz area is because the human ear is most sensitive around 2-5KHz so an increase in that area gives more return.

Temporal significance vs speech signal compression

It is common for compression to be used on the LF signal in transmitters so there are a few things to say about it. Compression can impair the hearing perception if it flattens out the signal envelope. Temporal level changes in speech are necessary as they are responsible for several aspects of auditory perception and intelligibility, including loudness, pitch and timbre perception. In phonemic terms this corresponds to articulatory information. This has been researched a lot around, in connection with the development of signal technology for hearing aids and interested readers can read about this here and here. This means that if you want to optimize the speech perception for the listener, then compression should not be done with too fast attack time, since the natural initial transients in the speech then decrease or flatten. But why is it not good to have as high a signal as possible all the time? Well, human hearing perception detects changes in sound not only when sound comes on but also when sound decreases ordisappears. An example of that is when people do hearing tests with tones where a button is to be pressed when a tone of a certain frequency is heard. At the very lowest audible levels, it is often the case that a reverse detection of the sound occurs when the sound disappears. That is, only when the approximately second-long tone is released does the person hear that there was a sound and then press the button. This suggests that transients and thus temporal level changes in the speech signal need to be left for an optimal perception for the listener. If you are interested, look at this interesting study .


I have mentioned about hearing aids to present an analogy to hf ham radio and thus what can be done to improve intelligibility for those who we might talk to so they can hear what we say. Then I thoght about another thing, related to hearing loss which might be of interest for some hams out there. It can also relate to the importance of a good AGC.
Recruitment is always a byproduct of a sensorineural hearing loss, not conductive hearing loss. It means that sounds are perceived as either too low or getting too loud too fast, if the sound gets too high. Dynamics in sound don't work. To improve speech perception in this, a common measure to work around this, among other things, is to increase the gain in hearing aids at lower in-levels, while medium in-levels levels are less gained and higher in-levels are usually not amplified or even lowered (unless there is (also) some degree of conductive hearing loss). In other words, signal compression. So, signal compression is used to treat sensorineural hearing loss. So, loud sounds are heard well or rather too loud which can be difficult to handle. This means that, in professional hearing aids used to (also) treat sensorineural hearing loss, a gradual level compression is made within the respective frequency ranges: weak sounds are mostly amplified, medium sounds are amplified slightly and strong sounds are not amplified at all or even lowered.
The other type, conductive hearing loss, is caused by impaired mobility of the eardrum (due to injury) and/or by impaired mobility in the area of the middle ear bones, the ossicles (malleus, incus, stapes), which transmit the mechanical vibrations to the cochlea, the inner ear. For people with conductive hearing loss only, hearing aids have linear gain and usually no compression.
For hams with sensorineural hearing loss, it could be a problem if the AGC in the receiver doesn't compress the signal fast enough and/or too little.

Not all qrp transceivers have AGC

► I want to call attention to the fact that many qrp transceivers don't have AGC which, is unintelligible. Using an cw/ssb transceiver/radio/receiver without AGC can lead to very unpleasant listening experiences which can even be harmful for the ears, specially with headphones.
An AGC circuit can be designed by any somewhat design-experienced builder, and some AGC circuits can probably be found on the internet for some models. Yet still it is strange why all qrp transceivers don't have it, there is no reason at all not to have it and it could be switchable on/off.

Which qrp transceivers have AGC?

► Some receivers have more unique AGC-designs and K1 is an example, that according to many users seems to have a receiver with a better dynamics. When listening to a weak signal, it can feel better to listen to an uncompressed sound with no AGC but if some qrn, spikes or stronger QRM comes in, well it's not that nice. A good AGC circuit could leave the dynamics as it is, at low levels, with an variable level where the AGC would be activated. But most AGC-circuits compress most of the dynamics.
To get rid of the compression sound on stronger signals is easy, just use RF-gain, if available.

So what about the question, a good question, and unless I wrongly include or forget, the answer is:
Elecraft�: K1, KX1, K2 (IF derived)
Hendricks Qrp Kits: Weber Dual Bander
Juma: TRX1, TRX2
Qrpproject: Hobo, Mosquita lll, Tramp 8 (IF derived), Speaky
Ten-tec: 1300-series, R4020
Wilderness Radio: NorCal 40a, Sierra, SST

Headphones should never be used with a radio without AGC. Better headphones should be used which have a more wide sound. It would have been nice if manufacturers of transceivers without AGC have added AGC-kits which could be built in to improve the current transceivers.

QRP transceiver list - pre-assembled and kits

► Just a few words in a haste (swedish: ord i hastan). So if you are a newcomer it could be wise to look for some of the smaller kits although maybe not small in regards of component size but in complexity, since smaller surface mount components are used with a smaller pcb design so it may need some basic circuit board experience first. Some of the kits easier to handle, depending on your skills. At least a multimeter and preferably an oscilloscope is needed. Other most important electronic test equipment would be a signal/rf/arbitrary waveform generator and a rf spectrum analyzer.

Added more qrp transceiver kits below, the EFE-40 SSB by TA3OM and the Foxx-3 CW (80, 60, 40, 30 or 20m) by Kanga Products which also sells Openqrp and Rockmite (by QRPme) in UK/Europe. Foxx-3 CW appears to use DSB according to the homepage.

December 17th - added more kits, by ozQRP and QRPme.

Qrp transceiver kits in alphabetical order,

The arrow-images below are links to each vendor's or brand's homepage(s).

Arizona ScQRPions

Ft. Tuthill 80



Breadboard Radio

Splinter II 40 meter QRPp ca 0.45 W (VXO 5-7 kHz).




EGV-40, ILER 17 mk2, ILER 20 mk2, ILER 40 mk2,


K1, K2, KX1, KX3


NW20, NW30, NW40, NW80



Kanga Products

Foxx-3 CW (DSB 20, 30, 40, 60, 80 or 160),
Open QRP 40m (original source, no kits now - openqrp.com, general info - openqrp.org by K1EL)
Rockmite (also sold by QRPme - (originally by Small wonder labs))

Kits and Parts

QRPp 10, 15, 17, 20, 30, 40, 80, 160 - "1 Watter"

LNR Precision

FX-4a, LD-5, Mountain tooper


MFJ-90nn, MFJ-91n0B(X), MFJ-92nn, MFJ-93nnK/W, MFJ-94nn(X)





Oak Hills Research



MDT SSB (DSB), (MST2 SSB - nomore available, being redesigned)



QRP kits
Pacific Antenna

BitX20A/17A, PFR3B, Ft. Tuthill 15, Ft. Tuthill 160, Multi-band DC, Weber tri-bander, SMK-2, KD1JV survivor, DCxx


Rockmite (also sold by Kanga Products - (originally by Small wonder labs)),
Lil Squall, Micro80D, Reggie ][


Hegau, Hobo, Miss Mosquita, Sparrow, Blue cool radio, Speaky, Tramp 8




1380 (the 1320, 1330 and 1340 seem discontinued), 506 Rebel, 507 Patriot, 539 Argonaut VI

Walford Electronics

Lydford, Minster

Wilderness Radio

SST, Norcal 40A, Sierra




EK1A, HB-1A, HB-1B mk3, TJ5A, TJ2B,

QRP SDR transceivers / receivers





Peaberry SDR V2 kit 160-10m, Peaberry SDR V2 assembled 60/40/30/20m

Aliva kits






FlexRadio Systems


Genesis Radio

Genesis G59



Pileup Communications


SDR Cube

SDR Cube


Built SoftRock RXTX Ensemble Transceiver, SoftRock RXTX Ensemble Transceiver kit

SoftRock RXTX Ensemble Transceiver kit

QRP transceiver comparison

Among all the info below, some qrpers have made overviews or tried out several qrp rigs so I add this little section here. When different transceivers reviews are made by one and the same user, the info can be looken at with a more objective comparison.
QRP Transceiver Kits: Six Reports from the Field (pdf)
K3WWP's QRP Rigs List

QRP sdr transceivers

Until onw, there are a few of these and probable they will be more and more used. Those who build need to know something about software too, but the already built ones will be more user-friendly, such as the KX3.

Elecraft� KX3 (QRP) SDR SSB/CW/DATA/AM/FM transceiver

Elecraft® KX3 (QRP) transceiver

Elecraft� KX3 160 - 10 meter (QRP) SDR SSB/CW/DATA/AM/FM transceiver

The Elecraft� KX3 It's analog performance is set high with the use of fast and high resolution AD conversion. It's overall performance is then accomplished with DSP which makes it possible to define the characteristics by means of software. Hence, as the software will be upgradeable, its performance will be improved as well. Furthermore, a number of other features are included such as dual watch and data modes. A DSP provides noise reduction, noise blanker, auto-notch as well as stereo audio effects with an 8-band audio equalizer. To read more about it, just check out the homepage.


Elecraft� KX3 - elecraft.com

Flex Radio FLEX-1500 QRP SDR transceiver

Flex-1500� - Click on the images for double size or here for a large image of the rear side.


FLEX-1500� home page - flexradio.com
FLEX-1500 Datasheet (786.9 KiB) - flexradio.com
FLEX-1500� block diagram - flexradio.com
FLEX-1500� manual - flexradio.com
FLEX-1500� quick start guide - flexradio.com
FLEX-1500� service manual - flexradio.com
FLEX-1500� PowerSDR� keyboard mapping file - flexradio.com
FLEX-1500� PowerSDR� v2.7.2 release notes - flexradio.com


FlexRadio FLEX-1500� Reviews - eham.net
Review discrepancy between Flex-1500 & Flex-3000 - eham.net

SDR Cube QRP SSB CW transceiver

The SDR Cube a one-band QRP transceiver with an embedded DSP controller coupled with a Softrock RxTx v6.3 RF front end. The size of each of the Cube's sides is 4". Built-in user interface: graphic LCD for spectrum display, typical controls for frequency, mode and signal management, and I/O jacks for connection to the outside world. The Cube�s design is optimized to internally accommodate the popular Softrock electronics. Different from other experimenter �single board� solutions, the Cube was designed from the start to serve as a full transceiver. The SDR Cube is a totally self-contained, embedded software defined radio (transceiver) for CW and SSB operation. It uses a Softrock for the RF front end electronics (RF mixer, amplifiers and filters) and an embedded digital signal processor with software programmed to perform as an HF modem. This programmability is the essence of an SDR�s ability to dynamically support virtually any modulation mode. A personal computer (PC) is not needed. A blue graphic display showing the transceiver settings and an exciting 8 kHz-wide band scope of spectrum signals, and the popular Softrock RXTX v6.3 board. The SDR Cube may also be used with any of the 11,000 other Softrocks in the field today, via the expansion port on the rear panel. Many details are available at the product website (www.sdr-cube.com), and active online user discussion occurs in the SDR-Cube Group in Yahoo Groups.


SDR Cube - sdr-cube.com
SDR Cube Transceiver OPERATING MANUAL - sdr-cube.com
SDR SDR Cube - A Portable Software Defined Radio Utilizing An Embedded DSP Engine for Quadrature Sampling Transceivers - sdr-cube.com


According to the fivedash.com homepage the RXTX Ensemble transceiver can be ordered a kit or built.


Softrock - wb5rvz.com
Softrock - fivedash.com


Softrock reviews - eham.net

Softrock related:

Softrockradio - softrockradio.org
On this page, the maker of softrockradio.org mentions his ham radio parts store, which sofar is on a trial basis.
The Parts Place - thepartsplace.k5nwa.com

SDR buzz forum - sdrbuzz.com/forum
SoftRock Multiband Transcievers - sdrbuzz.com/forum
Softrock RXTX V6.3 - Xtall - Band Pass Filter(s) - golddredgervideo.com/wb5rvz

Softrock QRP transceiver RXTX Ensemble kit

Click on the image for double size or here for a large image.

On the Ensemble RXTX - Home Page - wb5rvz.org page, it is said that the Ensemble kit basically is a RXTX V6.3 with the difference that its band-specific components are fixed and predetermined (as opposed to the plug-in daughter boards for these functions in the RXTX V6.3). So the kit isn't compatible with the Mobo add-on series, which depend upon the RXTX V6.3's plug and socket arrangements.

This transceiver kit comes in five versions: 160, 80/40, 40/30/20, 30/20/17 or 15/12/10 meters.

The SoftRock RXTX Ensemble Transceiver Kit provides a 1 watt SDR transceiver that can be built for one of the following four band groups: 160m, 80m/40m, 30m/20m/17m or 15m/12m/10m. Components are included for all four options and can be assembled at the builders choice. The kit combines the functionality of the prior SoftRock v6.3 RXTX+Xtall Transceiver Kit, the USB I2C Interface Kit and the PA Filter Kit on a single circuit board with connectors along one edge for easy access.

QRP Transceivers

There are some ordinary transceiver kits that are somewhat simple, and for those with limited time, some are available as pre-built which can be a reason for those who want to use the time for modifications or are impatient to do that.

Arizona ScQRPions - Ft. Tuthill 80 QRP CW Transceiver


Ft. Tuthill 80 QRP CW transceiver - Arizona ScQRPions

Ft Tuthill 80 Transceiver. An 80m QRP CW transceiver kit. DC receiver. Designed by Dan Tayloe (N7VE) with assistance from Doug Hendricks (KI6DS) of Hendricks QRP Kits.
My impression is that this is very well designed transceiver. Take a look at the
Tuthill filter page with its valuable information.
A frequency counter is an option.



Direct conversion receiver - No AGC
� MDS sensitivity: -116 dBm in a 700 Hz bandwidth.
� RIT ~ +/- 1.2KHz -> Because it is a DC receiver, possible to move from USB to LSB to allow moving away from an interfering signal on the opposite sideband.
� RX bandwidth: ~700 Hz.
� RX current: ~28 ma at 12v
� 5 pole R/C active filter selectivity: Nominally 3 dB down at 1 KHz, 40 dB down at ~2 KHz, 100 dB down at ~8 KHz.
� 3rd order distortion (IP3): +25 dBm (10 KHz away limited by the R/C filter response).
� Blocking Dynamic Range (BDR): ~100 db (10 KHz away limited by the R/C filter response).
� Audio limiting: The audio output has been designed to drive headphones and have been provided with diode limiting to protect the user from sudden, large signals.


� Power Out: 0.1-2.5w (12v)
� TX current: At 2.5w out/12v 670 mA current drain.
� All output harmonics: Less than -49 dB down.
� Transmit protection - When the TX is left key down for more than 3 seconds, the transmitter goes into a "dotting" mode (33% duty cycle) to protect the finals.


� Supply voltage: 12-13.8v
� Tuning range: 50 KHz segment of the 80m CW band. Can be extended to 80 KHz by using other half of main tuning capacitor.
� Spot switch allows setting TX spotting precisely. Spotting mode is entered via a push button. A 800 Hz blip is sent once a second to remind the user that the rig is in the "spot" mode.
Accessory 5v output - A regulated 5V output is provided for external accessories such as a keyer kit.


Ft. Tuthill 80m Transceiver - azscqrpions.com
Tuthill filter presentation - Active R/C Filter Design and 80M Unichip Plus DC XCVR - azscqrpions.org

Yahoo Users Group for the Az ScQRPions Fort Tuthill 80m Transceiver
Board completion report (JL1KRA) - Yahoo user groups


The Fort Tuthill 80 � A Direct Conversion Transceiver For 80M - Dave Richards AA7EE
The Tut 80 Complete - Dave Richards AA7EE
Ft. Tuthill 80 Meter Transceiver is now available - W2LJ's Blog
Ft. Tuthill 80 Transceiver Build - WF7T.net
Ft. Tuthill 80 Transceiver Build - Update 1 - WF7T.net
Ft. Tuthill 80 Transceiver Build - Update 2 - WF7T.net
Ft. Tuthill 80 An Innovative 80M DC Transceiver By Dan Tayloe, N7VE. - wa0itp.com
FtTuthill80 � Az ScQRPions FtTuthill80 Transceiver - M1KTA's QRP ham radio blog


Elecraft� is probably the most popular QRP transceiver (kit) manufacturer. As seen on the homepage they also have some other products too.
Elecraft - Reflections From Their Reflector
The Elecraft Archives

Elecraft� K1 QRP CW transceiver


Elecraft� K1 QRP CW transceiver

(Click on image for 4x image. Click here for a large image.)

Elecraft� K1 with its options is maybe the most popular qrp transceiver also available as a kit. It has 2 or 4 bands. Less advanced than an ordinary HF-transceiver yet more advanced than other basic qrp rigs.
To get a direct and very informative view of the K1 function, look at the Elecraft� K1 quick reference.



� Single conversion superhet.
� Sensitivity: ~0.15 �V (attenuator Off.)
� Switchable attenuator with LED status indicator.
� Three programmable filter bandwidths .
� RX current: > ~55mA
� Narrow double-tuned bandpass filters.
� Bar graph S-Meter.


� Diode-switched full break-in; programmable delay.
� CW power out: 0-5 watts or higher.
� PA: SWR-protected PA transistor.
� Harmonics/spurious outputs: better than �40 dBc.

Cw features:

� Built in memory keyer with iambic modes A and B.
� 9 � 50 wpm with internal keyer, > 70 WPM ext. keying.
� Two 80-byte EEPROM message buffers.
� Auto-repeat and message chaining.
� Programmable message repeat interval, 1-250 sec. (longer delays useful for beacons).
� Keying jack for a hand key or computer as well as a keyer paddle.


� Sharp 4-crystal filter.
� IF: 4.915 MHz
� 3 MHz low-noise analog VFO.
� Smooth 10-turn potentiometer VFO.
� 100Hz display resolution.
� Size: H 2.2" W 5.2" D 5.6"
� Weight: 1.4 lb
� Supply voltage: 9-12V.


Elecraft� K1 - elecraft.com
K1 and accessories - Price list - elecraft.com

K1 download page - See all downloads here - elecraft.com
K1 data sheet july 2014 - elecraft.com
K1 manual Rev J, March 24, 2015 - elecraft.com
K1 manual errata Rev J-1, August 8, 2015 - elecraft.com
K1 Quick Reference Card (pdf) - elecraft.com
Cheap 'N Dirty Signal Tracing in the K1 (pdf) - elecraft.com

The K1 area pages

On the one page Elecraft - Reflections From Their Reflector that was mentioned above, there are a lot of great topics and of course about K1 too. The two K1 sections below are on this same page.

K1 Area - 5 Watt QRP Transceiver
K1 and K2 Area

Two versions are available:


With two bands, comes with the 2-band filter module KFL1-2 with any two bands of 80, 40, 30 20, 17 and 15 meters.


with four bands, comes with the 4-band filter module KFL1-4 which covers 40, 30 or 20 and 17 or 15 meters.

Therefore, if 80m is of concern, the choice is between K1-2 or K1-4 plus the KFL-2 filter. $299.95 vs $479.90 ($399.95 + $79.95) - (As seen on their price list page May 2011). So if you are a devoted always-80m user then the K1-2 is probably what you'd prefer.

K1 Options: (as on the K1 homepage May 2011):

KFL1-2 2-band filter module:

KFL1-2 picture
KFL1-2 instruction sheet (pdf)

KFL1-4 4-band filter module:

KFL1-4 picture
KFL1-4 Manual (pdf)
KFL1-4 Manual Errata (pdf)

KNB1 Noise Blanker:

KNB1 picture
KNB1 Manual (pdf)
KNB1 Manual Errata (pdf)

KAT1 Internal Automatic Antenna Tuner:

KAT1 homepage
KAT1 Manual (pdf)
KAT1 Manual Errata (pdf)

KBT1 Internal Battery Adapter:

KBT1 homepage
KBT1 Manual (pdf)
KBT1 Manual Errata (pdf)

KTS1 Wide Range Tilt Stand :

KTS1 picture
KTS1 Instruction Sheet (pdf)

K1 LCD Backlight Mod Kit:

K1 LCD Backlight Mod Kit
KTS1 Manual (pdf)


I guess there are some K1-users who have one of each, (Today $299.95 + $399.95 = $699.90) .
Besides, thinking about the next maximum, will there be a 12/10 meter upgrade?!
Or read about how someone tells about getting 12/10m on the K1.
K1 on 10 meters: helpful advice
K1 on 10 meters: helpful advice 2
K1 on 10 meters: helpful advice 3
10 meters on K1 - component values
K1 on 12/10m (was: 10 meters on K1 - component values)

Some (subjective) views by K1 users:
K1 sounds cleaner and/or even subtly quieter and as with certain other qrp rigs, K1 is better in some respects than many other standard HF transceivers.

Wilderness Sierra is somewhat comparable somewhat in complexity. The Sierra is a couple years older. These rigs are both designed by Wayne Burdick (N6KR).
Elecraft K1 vs. Wilderness Sierra


Elecraft� K1 reviews - Eham.net
Elecraft� K1 reviews - Eham.net
K1 80 or 150kHz and how to do VFO Linearization
On the link above, you can also read about the AGC:
"Last evening I did the "C31 cap change mod" to s/n 0017. I replaced the 2.2 uf with a .47 uf and the difference was amazing. The AGC is much more responsive with the new cap in place."
AGC again:
C31 to 1uF (from 2.2uF)
C67 to 0.1uF (from 2.2uF) Ref:
K1 AGC Notes (from Elecraft Reflector)
[Elecraft] K1 revisited

K1 AGC time constant
Elecraft K1 - Forum & mailing list archive
Building the Elecraft K1 Transceiver
Elecraft K1 4 band QRP Transceiver
Elecraft K1 Excessive Current on Transmit
Elecracft K1 Multi-Band CW Transceiver
Eham forum, click on "Search" to get the results.
Elecraft K1 - Why Build Kits?
Better CW sound on the K1, vs K2 ?

K1 mods:
Elecraft K1 Modifications - jl3amk.org

Elecraft� KX1 QRP CW transceiver

Elecraft® KX1 QRP CW transceiver

Elecraft� KX1 QRP CW transceiver

(Click on image for 4x image. Click here for a large image.)

Improvements and mods

Writing this in Dec 30 2015 since I took a notice of what I saw others wrote, if you think about this rig. Things you could plan how you would do to take into consideration, as for any other rigs or kits.
Anyway, here are the pages I saw:
KX1 review by GEIIM, on top of the page - eham.net
Elecraft KX1 - nice radio but rooms for improvement in the construction manual - forums.qrz.com
Alright then, below what I wrote several years ago.

Elecraft� KX1 with its options is one of the most popular transceivers available as kits.
The KX1 covers the full 20 and 40 meter bands, and optionally 80 and 30 meters. A DDS based VFO which performs tuning outside each band on SWL band segments. A variable bandwidth crystal filter permits reception of ssb, cw and zero-beat AM. It can be used 20 to 30 hours from internal batteries at the 1 to 2 watt level. A special feature enables operation without the display, if the CW feedback feature is turned on (audio Morse code). This provides audible announcement for the VFO dial, menu text, and all controls.

An internal automatic antenna tuner, KXAT1, enables wire antennas etc to be used on all bands. The KXPD1 clip-on keyer paddle is designed for the KX1 and it can be set for both left- or right hand use. The KXB3080 band module adds the 30 and 80 meter bands.

To get a direct and very informative view of the KX1 function, look at the KX1 quick reference.



� Single conversion superhet
� Sensitivity: ~ 0.2 �V for 10 dB (S+N)/N
� Selectivity: 3-pole variable-bandwidth crystal filter ~0.3-2KHz
� Bar-graph S-meter.
� Tuning rates 10 Hz, 100 Hz, 1 kHz, and 5 kHz.
� Audio output: 0.1 watt into 8-ohm load.
� RIT: 20 Hz steps, +/- 5 kHz.
� USB and LSB receive available on all bands.


� Spurious content at 3 to 4 w, 2nd harmonic -40 dB typ. with LPF adjustment (see page 59).
� Max. power output:
9 V supply ~1.5-2W (battery use)
12V supply ~3 - 4W
� Spurious content: 2nd harmonic-40 dB @ 3-4 W (with LPF adjustment, see page 59)
� Load tolerance 2:1 or better SWR recommended.

Band module coverage:

� KXB30:
8.0 - 12.5 MHz receive and 10.1 - 10.15 MHz transmit.
� KXB3080 (30 and 80m):
8.0 - 12.5 MHz receive and 10.1 - 10.15 MHz transmit.
1.5 -   5.5 MHz receive and   3.5 -   4.0 MHz transmit.
Adding either module also greatly improves sensitivity in the 49-meter band (5.9-6.4 MHz).

Cw features:

� Full QSK with variable QSK delay.
� Sidetone pitch 500-650 Hz in 10 Hz steps � Sidetone adjustable volume.
Keyer 8-50 WPM; Lambic modes A and B; 2 message buffers; auto-repeat.
� Programmable message repeat interval.


� Bands: 20 and 40m. With KXB3080: 30 and 80m.
� Bands covered:
Receive: 5.0-9.5 and 12.0-16.5 MHz
Transmit: 7.000 to 7.300, and 14.000 to 4.350 MHz
� Current drain:
Receive: ~35-40 mA max (headphones, LED display timed out, 30-m or 30/80-m option installed)
Transmit: 300-700 mA (varies with supply voltage and power output setting)
LED current: Adds 1 - 10mA
� Supply voltage: 7-14 V (8 V min. recommended)
� Built-in battery voltage monitoring
� Frequency control DDS with 50 MHz crystal reference.
� DDS VFO drift < 50 Hz per hour after 5-minute warm-up at 25�C.
� 9 frequency memories
� Display 3-digit LED w/bargraph mode.
� Size: (H x W x D)
Cabinet 1.2 x 5.3 x 3.0" (3 x 13.5 x 8 cm)
Overall 1.4 x 5.8 x 3.0" (3.5 x 15 x 8 cm)
� Weight 9 oz. (0.25 kg), excluding options.


KX1 Ultra-Portable CW Transceiver Kit - Elecraft.com
KX1 and accessories - Price list - elecraft.com

KX1 data sheet - Elecraft.com
KX1 manual Rev E (May 21, 2010) - Elecraft.com
KX1 downloads - Elecraft.com
KX1 Quick Reference Card (pdf) - elecraft.com
Elecraft KX1 Transceiver: Frequently Asked Questions - Elecraft.com

KX1 Options: (as on the KX1 homepage May 2011):

KXAT1 internal automatic antenna tuner:

KXAT1 picture
KXAT1 manual

KXPD1 clip-on keyer paddle:

KXPD1 picture
KXPD1 manual

KXB3080 2 band module. Allows reception from 1.0 to 16.5 MHz:

KXB3080 picture
KXB3080 Rev B Manual May 16 2012
KXB3080 Rev A-1 Manual Errata - elecraft.com


Single conversion superhet.
Sensitivity: ~0.15 �V (attn. Off.)
Switchable attenuator with LED status indicator.
Three programmable filter bandwidths .
RX current: > ~55mA
Narrow double-tuned bandpass filters.
Bar graph S-Meter.


Diode-switched full break-in; programmable delay.
CW power out: 0-5 watts or higher.
PA: SWR-protected PA transistor.
Harmonics/spurious outputs: better than �40 dBc.

Cw features:

2 memory keyer with iambic modes A and B.
8 � 50 wpm with int. keyer, > 70 WPM ext. keying.
Programmable message repeat interval.
?? Adjustable sidetone volume and pitch.


Sharp 4-crystal filter.
IF: 4.915 MHz
3 MHz low-noise analog VFO.
Smooth 10-turn potentiometer VFO.
100Hz display resolution.
Size: 1.2 x 3 x 5.3 inches (3 x 7.5 x 13 cm).
Weight: 9 ounces (11 with ATU and keyer paddle.)
Supply voltage: 9-12V.


Elecraft� KX1 reviews - Eham.net
KXPD1 paddle kit reviews - Eham.net
CQ Reviews: Elecraft�s New KX1 CW Transceiver Kit
Elecraft KX1 - A Wonder of Modern Radio Technology
Elecraft KX1 Trail Radio
The Evolution of the Elecraft KX1 Transceiver - shedberg.livejournal.com
Elecraft KX1 #1740 - The first 100 QSOs
A Case for the KX1
Elecraft KX1 - Forum & mailing list archive

Elecraft� K2 QRP (SSB) CW transceiver


Elecraft� K2 QRP (SSB) CW transceiver


K2 and K2/100 All HF Band CW/SSB Transceiver Kits
K2 manual download page - elecraft.com
Elecraft� K2 HF transceiver numbers - Performance Comparisons - elecraft.com
CQ Reviews - The Elecraft K2/100 Getting Back to Basics - elecraft.com
NCJ Reviews: The ElecraftK2�A Contester�s Perspective - elecraft.com


Elecraft K2 reviews (qrp section)- www.eham.net
Elecraft K2 reviews - www.eham.net
Elecraft K2/100 reviews - www.eham.net
Elecraft K2 and K3 Transceivers - www.cliftonlaboratories.com (Great tech resource !)
The Elecraft K2 Transceiver Kit - www.g4ilo.com
Elecraft K2


General modifications applicable to any Elecraft K2

Elecraft K2 Tech Notes:

Building & Using The Elecraft K2 HF Transceiver
Cheap 'N Dirty Signal Tracing in the K2
Care and feeding of a K2 battery
spanish: Elecraft K2 review
French: Elecraft K2 review
K2 microphone audio improvements
Measuring The Elecraft K2 SSB TX/RX Audio Response, by KD2BD
LA3ZA Radio % Electronics: Unofficial Guide to Elecraft K2 Mods

Emtech NW20/30/40/80 QRP CW transceivers


Emtech NW20/30/40/80 QRP CW transceiver

(Click on image for 4x image. Click here for a large image.)

A superheterodyne receiver with a variable bandwidth IF chain crystal filter. Optional fixed-width audio filter allows better selectivity. RF out up to 5 Watts.
2 NE602s are used in the front end and BFO oscillator.



� Superhet receiver - No AGC
� Sensitivity: �125 dBm
� Variable bandwidth crystal filter.
� 4 pole crystal filter (nominal 400Hz at 3dB point)
� RF Tuning Range: 6.999 - 7.201MHz, test 7.040MHz
� MDS sensitivity: -118 to -130 dBm (.07uV) (from wide to narrow on variable BW filter)
� IF rejection: 69dB
� Image rejection: 124dB
� Blocking dynamic range: 100dB
� IMD dynamic range: 78dB
� IF/Audio bandwidth: 534Hz
� Audio power output (into 8 O): 1.5W
� 2nd Order IMD dynamic range: 101dB
� 2nd Order Intercept: +77dBm


� Power Out: 4.8W - ~3.7W at 11V, 6.2W at 13.5V
� TX current: At 2.5w out/12v 670 mA current drain.
� 2nd Harmonic: -35dB
� 3nd Harmonic: -46dB
� PA stage gain: 25dB


� Full QSK.
� VFO Frequency: 5.000 - 4.798MHz, test 4.959MHz
� VFO Drift from power on:
Measured Drift (Hz): 1 Min: +380, 2 Min: +320, 3 Min: +90, 4 Min:-60, 5 Min: -10.
� 4-pole crystal filter: 6dB Bandwidth: 1.7KHz - 150Hz wide to narrow.
� Receive current: ~52mA - ~48mA at 11V, ~58 mA at 13.5V
� Transmit current: 1.09A - ~0.92A at 11V, 1.32A at 13.5V
� Tuning ranges:
80 Meters: 3.500 to 3.750 MHz
40 Meters: 7.000 to 7.200 MHz
30 Meters: 10.100 to 10.135 MHz
20 Meters: 14.000 to 14.090 MHz
� IF frequency:
80 Meters:  9.6 MHz
40 Meters: 12.0 MHz
30 Meters: 12.0 MHz
20 Meters:  9.6 MHz
� VFO range:
80 Meters: 6.100 - 5.850 MHz
40 Meters: 5.000 - 4.800 MHz
30 Meters: 1.900 - 1.865 MHz
20 Meters: 4.470 - 4.400 MHz


NW Series Monoband CW Transceiver 80, 40, 30, 20 meters - emtech.steadynet.com
NW30 review - emtech.steadynet.com
Emtech NW schematic - emtech.steadynet.com


Emtech NW30 reviews - Eham.net
Emtech NW40 reviews - Eham.net
QRP Transceiver Kits: Six Reports from the Field (pdf)
NW20 review - w0ch.net
NW80 review - qsl.net/wb6dwd


Juma is run by OH2NLT and OH7SV in Finland and represents various ham radio equipment such as receivers, transmitters, keyer, linear amplifiers and more and as shown here, a pair of HF transceivers. It is all in the online shop page where you select where your country belongs.

Juma TRX1 CW DSB QRP transceiver


Juma TRX1 QRP CW/DSB transceiver

The TRX1 is a direct conversion CW/DSB transceiver for 80 and 40m, 5W out, RIT, currents RX 60 mA - TX 1.2 A, filters SSB 2.4 kHz/CW 900Hz, graphical S-meter, relative graphical output indicator, relative graphical reverse power indicator. Also a built in keyer (JUMA-KEYER1),. There is no need to wound coils when building.

From the first homepage below there are many other pages except for the ones shown here.


Juma TRX1
RX filters 2.4 kHz for SSB and 900 Hz for CW - Graphic diagram
Some internal TRX1 adjustments
TRX1 main board components
JUMA-TRX1 DDS board adjustments and software setup

Juma TRX2 two band / TRX2A allband CW SSB QRP transceivers


Juma TRX2 CW/SSB QRP transceiver

The TRX2 has the 80m and 40m ham bands and the TRX2A has all bands with a general coverage receiver.


TRX2/TRX2A specifications (pdf)
Juma TRX2
TRX2 Technical kit information
Direct Conversion HF Transceiver with DDS LO
TRX2/TRX2A specifications (pdf)


Juma TRX2 reviews - Eham.net
Juma TRX2A (Allband) reviews - Eham.net
Juma TRX2A (Allband) reviews - Eham.net
QRP rigs: Juma TRX2A


This transceiver is discontinued.

QRP transceiver ATS-4

QRP transceiver ATS-4

ATS-4 pages:

The ATS-4 - A miniature 5 band CW rig with digital mode capabilities.



� Sensitivity: 0.2 uV
� Selective CW filter
� 4 crystal IF filter
� Audio band pass filter
� Side adjust volume control for low profile case
� Audio derived S Meter bar graph


� CW power out:
� 4.5-5 Watt on all bands (at 12V), 2.5 watts at 9 volt
� Spurious outputs:- 43 dBc max

Cw features:

� Built in Iambic A or B mode keyer with three message memories
� Can convert Morse inputted via paddle to transmit as PSK31
(PSK31 and RTTY possible using Pocketdigi software on a PC, laptop, netbook or PDA)


� 80/40/30/20 and 17 or 15 meter bands. (17 or 15 meters selected at time of building)
� DDS VFO for wide tuning range
� VFO 50 Hz tuning steps
� Single step or auto increment tuning
� Last used frequency restored when changing bands � Stores last used frequency and other operating parameters when turned off.
� Battery saving auto shut off if not used for 15 minutes (can be disabled)
LCD display with back lighting
� RX current: 50 mA at no signal
� TX current: 680 mA maximum at 12V
� Power supply: 7 - 12 Violts
� Custom made aluminum case, painted and silk screened
� Size: 4.9" wide, 2.7" deep, 1" tall (about 1/3d larger than an Altoids tin)
� Weight: 6.3 oz.


ATS-4 - hoaglun.com


With the recent 9200-series, MFJ now has four series of qrp transceivers. Three for CW, 90xx, 92xx and 93xx/K/W series, and the SSB 94xx series which can be used for cw too, with a cw adaptor board. However it seems difficult to find info about this cw board and its name, MFJ-416, is only mentioned around the MFJ-9406.

Only the 93xx series are available as kits (K) where W stands for already wired. The 94xx series is available with or without microphone, *X.

MFJ-9015/17/20/30/40 QRP CW transceivers


MFJ-9015/17/20/30/40 CW transceiver

These have
Single conversion superhet receiver
5 watts
RIT +/- 1kHz
750Hz crystal filter
700Hz sine sidetone
3" speaker
Full QSK
Average RX current 50mA
Final amplifier tolerates up to VSWR 3:1 and can handle momentary feedline shorts or opens.. Price in August 2010 $209.95. MFJ accessories are MFJ-412 lambic keyer, MFJ-971 qrp tuner, MFJ-4114 NiCd power pack.
Specifications that differs between band models are


Frequency coverage

IF frequency

VFO frequency


21.000 - 21.200 MHz

16 MHz

5.000 - 5.200 MHz


18.060 - 18.115 MHz

16 MHz

2.060 - 2.115 MHz


14.000 - 14.075 MHz

10 MHz

4.000 - 4.200 MHz


10.100 - 10.150 MHz

6 MHz

4.000 - 4.150 MHz


7.100 - 7.150 MHz

12 MHz

4.850 - 5.000 MHz


MFJ-9015 info page - www.mfjenterprises.com
MFJ-9015 manual - www.mfjenterprises.com

MFJ-9017 info page - www.mfjenterprises.com
MFJ-9017 manual - www.mfjenterprises.com

MFJ-9020 info page - www.mfjenterprises.com
MFJ-9020 manual - www.mfjenterprises.com

MFJ-9030 info page - www.mfjenterprises.com
MFJ-9030 manual - www.mfjenterprises.com

MFJ-9040 info page - www.mfjenterprises.com
MFJ-9040 manual - www.mfjenterprises.com
MFJ-9040 reviews - www.mfjenterprises.com


MFJ 90-Series reviews - eham.net
MFJ-9040 review
Who says hamradio is expensive


MFJ-9215/17/20/30/40/80 QRP CW transceivers

A new qrp cw transceiver available for six bands, with band modules for theses bands, 15, 17, 20, 30, 40 and 80 meter. It is not entirely a MFJ transceiver because it is a lot like the HB1-A with some differences. To read about some of these read the MFJ 9200 review at eham.net.
Features include:
Built-in lambic keying with a manual-key sensor.
Programmable CQ message.
Seamless QSK T/R switching.
DDS frequency control with 100-Hz readout.
8 memory channels per band.
3 main-dial tuning rates.
RIT with 10-Hz tuning resolution.
Selectable IF-band-width for monitoring SSB or CW.
20-dB front-end attenuator.
Switched backlight for the LCD display.

Besides, the receiver overlaps international short wave broadcasting frequencies. The MFJ-9200 runs on a power source between 8 and 15 VDC and draws just 40 mA on receive when the display backlight is turned off.


MFJ 9215 info page - mfjenterprises.com
MFJ 9217 info page - mfjenterprises.com
MFJ 9220 info page - mfjenterprises.com
MFJ 9230 info page - mfjenterprises.com
MFJ 9240 info page - mfjenterprises.com
MFJ 9280 info page - mfjenterprises.com

MFJ 92nn manual - mfjenterprises.com


MFJ 9200 QRP Mini Multi Band Transceiver - eham.net
MFJ 9200 - kd8big.blogspot.com
MFJ 9200 - eham.net/ehamforum

9315/17/20/30/40/80 Cub QRP CW transceivers

QRP CW transceiver MFJ-9315/17/20/30/40/80 Cub

MFJ-9315/17/20/30/40/80 Cub CW QRP transceiver

QRP CW transceiver MFJ-9315/17/20/30/40/80 Cub

MFJ-9315/17/20/30/40/80 Cub QRP CW transceiver

The Cub can be ordered as a kit, MFJ-93xxK or already wired, MFJ-93xxW.
It is supposed to have a 0.2 uV sensitivity receiver, an AGC which holds the audio output over an 80-dB signal range, 100mW AF output, full QSK, click-free keying, adjustable transmit offset and receiver passband, currents about >40 mA on receive and about <400 mA on transmit. RF output is adjustable from 0 to about 2W up to 20m, 1.5W on 17m and 1W on 15m.

Many users have reported a significant VFO drift until warmed up for 15-30 minutes. Maybe other components could be chosen which temperature coefficients would compensate eachother more.
On the 40m version the VFO tunes in opposite direction.

The frequency ranges are supposed to be
MFJ-9380: 3.500 - 3560 MHz
MFJ-9340: 7.000 - 7.060 MHz
MFJ-9330: 10.100 - 10.120 MHz
MFJ-9320: 14.000 - 14.060 MHz
MFJ-9317: 18.068 - 18.118 MHz
MFJ-9315: 21.000 - 21.050 MHz


MFJ-9315K info page - www.mfjenterprises.com
MFJ-9315W info page - www.mfjenterprises.com

MFJ-9317K info page - www.mfjenterprises.com
MFJ-9317W info page - www.mfjenterprises.com
MFJ-9320K info page - www.mfjenterprises.com
MFJ-9320W info page - www.mfjenterprises.com
MFJ-9330K info page - www.mfjenterprises.com
MFJ-9330W info page - www.mfjenterprises.com
MFJ-9340K info page - www.mfjenterprises.com
MFJ-9340W info page - www.mfjenterprises.com
MFJ-9380K info page - www.mfjenterprises.com
MFJ-9380W info page - www.mfjenterprises.com


MFJ-9315K, 9317K, 9320K, 9330K, 9340K, 9380K - manual - www.mfjenterprises.com
MFJ-9315W, 9317W, 9320W, 9330W, 9340W, 9380W - manual - www.mfjenterprises.com


The MFJ Cub 9315K 1W HF CW Transceiver
MFJ 93xx Cub reviews - eham.net
MFJ 9330 Cub Arrives - wa3wsj.homestead.com
Building the MFJ Cub QRP transceiver kit - g4ilo.com
Cub tamed - just about - g4ilo.com
MFJ Cub QRP transceiver kit
MFJ's QRP Cub CW Transceiver - qsl.net/n1irz

MFJ Cub (MFJ-9380) Issues- qsl.net/n9bt

MFJ Cub mods
A Look at VFO Drift in the MFJ CubTM - w1hue.us
MFJ CubTM Tuning Linearization - w1hue.us
True QSK and Improved Keying for MFJ CubTM Transceivers - w1hue.us
Simple RIT for the MFJ CubTM - w1hue.us
Cub QSK Revisited - w1hue.us

MFJ-9402/06/10/20/40/75(X) (QRP) SSB (CW) transceivers


MFJ-9402/06/10/20/40/75(X) (QRP) SSB (CW) transceiver

Not really QRP with an average RF output 10W, Double balanced mixer front end, Single conversion superhet, audio derived AGC, 8:1 reduction drive ball bearing VFO tuning capacitor, audio >1W into a 3" speaker, RF speech processing, available CW adapter board (except for the 9475)- Semi-break in keying and sidetone.

The *X models come with a microphone.

The frequency ranges for each band is
3.750 - 4.000 MHz (SSB only)
7.150 - 7.300 MHz
14.150 - 14.350 MHz (For CW 14.000 14.100)
28.300 - 28.600 MHz
50.000 - 50.300 MHz
144.000 - 144.300 MHz


MFJ 94-Series - eham.net


MFJ-9402 info page - www.mfjenterprises.com
MFJ-9402X info page - www.mfjenterprises.com
MFJ-9402/X manual- www.mfjenterprises.com
MFJ-9402 reviews - mfjenterprises.com


MFJ-416 - mfjenterprise.com
MFJ-416 cw adapter instruction manual - mfjenterprise.com

MFJ-9406 info page - www.mfjenterprises.com
MFJ-9406X info page - www.mfjenterprises.com
MFJ-9406/X manual- www.mfjenterprises.com
MFJ-9406 reviews - mfjenterprises.com


Receiver Section:
Frequency Coverage 28.300-28.600 MHz
Receiver Type Single-conversion Superhet
Frequency Control: Crystal mixed heterodyne VFO
VFO Frequency 6.0 - 6.250 MHz
IF Frequency 10 MHz
IF Selectivity -6 dB @ 2.3 kHz
AGC: Audio-derived, 70-dB dynamic
Blocking Dynamic Range >100 dB
Sensitivity 0.15 uV for 12-dB S/N
Audio Output 0.5 Watts into 8 Ohms at 10% THD
Receive Current 60-mA, (S-meter lamp disabled)
Transmitter Section:
RF Power Output 20-Watts PEP
Suppression 45 dB
VSWR Tolerance: 3:1 VSWR
Maximum Current 2.2 Amps at 13.8 VDC
Speech Enhancement Syllabic RF-compression
Transmit Current 2.0 Amps @13.8 VDC

MFJ-9410 info page - www.mfjenterprises.com
MFJ-9410X info page - www.mfjenterprises.com
MFJ-9410/X manual- www.mfjenterprises.com
MFJ-9410 reviews - mfjenterprises.com

MFJ-9420 info page - www.mfjenterprises.com
MFJ-9420X info page - www.mfjenterprises.com
MFJ-9420/X manual- www.mfjenterprises.com
MFJ-9420 reviews - mfjenterprises.com


MFJ-9440 info page - www.mfjenterprises.com
MFJ-9440X info page - www.mfjenterprises.com
MFJ-9440/X manual- www.mfjenterprises.com
MFJ-9440 reviews - mfjenterprises.com


Receiver Section:
Frequency Coverage 3750 - 4000 kHz
Receiver Type Single-conversion Superhet
VFO Frequency 6.0 - 6.250 MHz
IF Frequency 10 MHz
IF Selectivity -6 dB @ 2.4 kHz
Blocking Dynamic Range >100 dB
Sensitivity 0.3-uV MDS
Audio Output 0.75 Watts into 8 Ohms at 10% THD
Receive Current 100 mA
Transmitter Section:
RF Power Output 12-Watts PEP (10-Watts average speech)
Suppression 45 dB
VSWR Tolerance: 3:1 VSWR
Maximum Current 2.2 Amps at 13.8 VDC
Speech Enhancement Syllabic RF-compression
Transmit Current 2.0 Amps @13.8 VDC

MFJ-9475 info page - www.mfjenterprises.com
MFJ-9475X info page - www.mfjenterprises.com
MFJ-9475/X manual- www.mfjenterprises.com
MFJ-9475 reviews - mfjenterprises.com

MKARS80 QRP SSB (CW) transceiver

QRP SSB (CW)  transceiver MKARS80

MKARS80 QRP SSB (CW) transceiver

This is an 80 meter LSB transceiver with digital LCD readout and there is a CW adapter for the MKARS80 available. Covers 3.5 - 3.8MHz. Power output is 5 watts. Sensitivity <1�V. RX current is about 120 mA and for TX 1.2A. 4 pole IF filter. There is no AGC.

MKARS (Milton Keynes Amateur Radio Society) is a large amateur radio club in Britain. (web site http://www.mkars.org.uk). In association with MKARS, the MKARS80 transceiver which is a development of BITX20, is available from radio-kits.co.uk.

SSB (CW) qrp transceiver MKARS80 circuit board

Circuit board for MKARS80


MKARS 80 - mkars.org
MKARS 80 - radio-kits.co.uk
MKARS80 CW adapter - radio-kits.co.uk
MKARS80 construction and user manual - radio-kits.co.uk, MKARS80 construction and user manual - mkars.org.uk
MKARS80 VFO drift modification - radio-kits.co.uk


Now look at the prices for these kits, latest to be found on http://www.radio-kits.co.uk/mkars80page.html;
Depending on where it is posted to:
Kit & case price : �60-64
Kit without case: �53-55
MKARS80 CW adapter �33-35
Un-drilled aluminium case for the mkars80 CW adapter �8.5


Options can only be purchased with a kit.
Knobs kit - large, medium and small knobs with 4 rubber feet: �2
Connector kit - Includes BNC plug, 3.5mm stereo jack, 3.5mm mono jack and 2.1mm DC plug: �2.50


MKARS80 reviews - eham.net
MKARS80 reviews - eham.net
The MKARS80 80M QRP SSB Transceiver
Built an excellent kit: MKARS80 80m
MKARS80 review - pa0rcl.com
MKARS 80 The Milton Keynes Amateur Radio Society 80 metre kit
MKARS80 user group - uk.groups.yahoo.com

One reviewer, Andy 2E0VPX, mentions two limitations on his web site. That the selectivity is not great, no AGC so that the RF gain has to be used frequently to avoid overload. At least an AGC should be able to design.
Of course, as said in the manual, because there is no AGC, it is not good to use headphones because the audio depends on the signal. So why did they not include that in the design for just a little more cost? Are there already now mods available?

LA6UOA/Trygve has a Pimp My Mkars80! web page. On his home page Trygve declares that ATUs are for losers, and I believe he mean lossy antennas!! There is a satellite image of the area where he resides, with the positions for the antennas he use.

AGC for the MKARS80

One user, Ron PA�RCL, modified one of his MKARS80s into a 'MKARS40'! However as pointed out on the page, it did not work well. With some help from others, he made some other mods too. One, to limit the least frequency number hundreds of Hz. Then, Ron made an AGC too and you can see the schematics here;
MKARS80 AGC schematic
MKARS80 review - pa0rcl.com
MKARS40 - pa0rcl.com


QRP CW transceiver NorCal 2N2/20/30/40

NorCal 2N2/20/30/40 QRP CW transceiver

The NorCal 2N2/XX series of transceivers are real, PN2222 based, QRP transceivers, available on 20, 30, or 40 meters. They are based on 10 years of prior K8IQY 2N2 designs � using a "best practices" approach, since the first 2N2/40 was designed over 10 years ago. This version of the design employs a PCB for building ease and predictable, consistent performance. Each kit comes complete with all parts, a painted and silkscreened case, and detailed assembly manual. The all analog design results in very low noise, affording a sensitivity of 0.2 uV, or better, depending on the band. This rig features 6 poles of crystal filtering, a stable VFO with 100 KHz band coverage, (50 KHz on 30M), world class QSK keying, built in sidetone, and room filling audio. A commercial quality PC Board is used, featuring thru hole construction with leaded parts, except the mixers which are large footprint SMT, commercial grade, level 7 devices. The output transistor is rugged, self-insulating, and sufficient for 5-watts of output power, adjustable down to the milliwatt level.

Norcal 2N2/XX - norcalqrp.org
Norcal 2N2/XX reviews - eham.net
Norcal 2N2/XX review
2N2/40 review - aa7ee.wordpress.com
2N2/XX - A 20, 30, or 40-Meter Discrete Component CW Transceiver Kit from the NorCal QRP Club
Norcal 2N2 - groups.yahoo.com
Le Norcal 2N2/40 - f6crp.pagesperso-orange.fr

Oak Hills Research

OHR is known for a number of previous transceivers, Sprint, QRP20, Explorer, Explorer 2, OHR 400 and OHR 500.

OHR 100A QRP CW transceiver

QRP HF CW transceiver OHR 100A

OHR 100A QRP CW transceiver

(Click on image for 2x image. Click here for a large image.)

The OHR100A is available for any of five bands, 80, 40, 30, 20, and 15 meter. The tuning range is 70kHz and can be applied for any band segment.

The default tuning ranges for each band
21.000 - 21.070 MHz
14.000 - 14.070 MHz
10.100 - 10.170 MHz
7.000 - 7.070 MHz
3.500 - 3.570 MHz
Single signal superhet receiver
RF out 5W and 4.5W on the 15 meter version. Output is adjustable down to a few mW.
RIT with a range of � 1KHz.
Four pole crystal IF filter with pre-matched crystals.
IF bandwidth front-panel adjustable from 1200Hz down to 400Hz.
Sidetone is a sine wave tone. Adjustable pitch and volume.
Smooth QSK
RF and AF gain.

New ultra stable pre-mix VFO system providing high side L.O. injection. Local Oscillator signal is available at rear panel jack for use with the DD-1 digital dial.
A great thing about the 100A is variable IF bandwidth (like the Emtech NW series).

OHR100A home page - ohr.com
I just found this one, 8 December 2015,
OHR100A transceiver details - single band cw transceiver kit - ohr.com
OHR100A reviews - eham.net
QRP Transceiver Kits: Six Reports from the Field (pdf) - ae5x.com
OHR keyer kit for OHR transceivers - mtechnologies.com


QRP SSB CW transceiver QROlle

QROlle QRP SSB CW transceiver

A 6 band qrp transceiver for the 160, 80, 40, 30, 17 and 15 meter bands. 10W SSB/CW. Developed by two in Sweden. Using SMD-components which can be premounted for an additional cost. CW sidetone 700Hz with adjustable volume. IF AGC. About 240mA RX current and 200mA with dimmed backlight.

QROlle II homepage
QROlle II Building documentation

Hendricks Qrp Kits

Qrp Kits.com has 6 transceivers and common for them is a somewhat higher RF power than most other qrp transceivers by other manufacturers.
Qrp kits ordering price list. On the homepage as above, check out the "QRP Building Tips" in the menu.

BitX20A, Bitx17A (QRP) SSB transceiver


BitX20A/BitX17A SSB QRP transceiver

Not really a qrp rig, since it outputs about 10 W but of course, and for portable use the power can be set lower and to keep batteries last longer. The design is made to use standard components. About 10W RF output. Superheterodyne receiver, free-running VFO.
The receiver has no AGC.


BitX20A/17A - qrpkits.com
BitX17A assembly manual- qrpkits.com
BitX20A assembly manual- qrpkits.com


BitX20A Yahoo user group
BitX20A reviews - eham.net
BITX20A - bitx20a.livejournal.com
BITX20A SSB Transceiver Assembly, Testing, and Operation - bitx20a.livejournal.com
BitX20A kit - modifications, videos, signal tracing and waveforms

Ft. Tuthill 15 QRP CW transceiver


Ft. Tuthill 15 QRP CW transceiver

The Tuthill 15 uses a direct conversion receiver which enables large signal performance. Receiver current is about 45 mA and if a frequency counter is used, about 22 mA is added. The receiver bandwidth is 700Hz with a five pole active RC filter, so it should be easily modified for other figures. The sensivity is specified to 0.16�V. The audio output is compressed.

The RF output is about 5W. Both RIT and XIT with a +/- 4kHz range. Two tuning rates are available, ~ 21.000 - 21.060 and 21.075 - 21.135 MHz. They are selected with a front panel range switch. A wider tuning range option, 21.000 - 21.090 and 21.075 - 21.165 MHz can be used, adding 45 kHz to the total tuning range.


Ft. Tuthill 15 CW QRP transceiver home page - qrpkits.com
Ft Tuthill 15m Assembly/Operation Manual - Part 1 (v6) - qrpkits.com
Ft Tuthill 15m Assembly/Operation Manual - Part 2 (v5) - qrpkits.com
Ft. Tuthill 15 schematic - qrpkits.com

MMR-40 Cw ssb qrp transceiver - RETIRED


MMR-40 CW SSB QRP transceiver

RX sensitivity: ~ 0.2 uV minimum detectable signal
Speaker output: ~ 0.5W
Current: RX >30 mA at no signal, TX ~ 0.9A at 6W out
Transmitter power out: 6 watts CW/pep typical at 13.8V supply.
Transmitter spurs: -50 dBc or better
SSB filter: ~ 400 Hz - 2.4 kHz
VFO drift: <200 Hz for 10 minutes warm up.
VFO tuning rate: ~ 13 kHz per knob revolution
Power supply: 11 to 14 volts, 12.5 to 13.8 recommended.

On the home page, it says:
Typical tuning range: SSB: 7.280 to 7.150 MHz CW: 7.100 to 6.700 MHz.

However in the manual, it says:
Typical tuning range: SSB: 7.260 to 7.130 MHz CW: 7.130 to 7.000 MHz.


MMR-40 - qrpkits.com
MMR-40 assembly manual - qrpkits.com


MMR-40 reviews - eham.net
I Built the MMR-40 QRP SSB/CW Rig: PTO Tip
Building the MMR-40 40-meter SSB/CW Rig - wb0smx.net
MMR40 S-Meter / Power Meter Circuit - wb0smx.net
I Built the MMR-40 QRP SSB/CW Rig: PTO Tip - k7og.net
First Contact with MMR-40 and another building tip - k7og.net

NADC 40/30 QRP CW transceiver - RETIRED


NADC 40 QRP CW transceiver

A qrp cw transceiver for either 30m or 40m. NADC stands for "nearly all discrete component". It uses a A612A mixer which a 4.00 MHz output, filtered by a three crystal IF filter. The transmitter uses three BS170 mosfet transistors wired in parallel. With a special PA circuitry described in the manual, 75% PA efficiency is achieved compared to the typical 50% in class C amplifiers.


Tuning range: ~ 60 kHz.
Warm up drift � 10 minutes at room temp, ~ 100 Hz.
MSD (minimum detectable signal): ~ 0.25 uV.
Band width: ~ 400 Hz.
RIT range: ~ -2.5 kHz/+1.1 kHz depending on frequency.
Receiver current: ~ 23 mA (~ 45 mA with digital dial) at no signal.
With digital dial: ~ 45 ma

3.5 watts out typical.
Spurs: � 45 dBc.
Transmitter current: 600 ma.
PA efficiency: ~ 75% typical.
Operating voltage range: 11.5 to 14 volts.


NADC-40 home page - qrpkits.com
NADC-40/30 manual - qrpkits.com


NADC-40 reviews - eham.net

PFR-3 QRP CW transceiver - replaced by PFR-3B


PFR-3 QRP CW transceiver

Does not have AGC. A qrp cw transceiver with the 20, 30 and 40 meter bands and full band coverage on tuning. It has a 4-crystal IF filter. Audio band-pass filter 600 Hz.

RX sensitivity: ~ 0.2 uV minimum detectable signal
Selectivity: ~ 300Hz
Currents: RX active ~ 47 mA, idle ~ 34 mA, at no signal. TX ~ 650 mA.
VFO drift: ~ 100 Hz for 10 minutes warm up.
Tuning range: ~ 60 kHz
Tuning rate: 50 or 100Hz
RF out ~ 5W


PFR-3 home page - qrpkits.com
PFR-3 manual - qrpkits.com
Hendricks PFR-3 Portable Field Radio - qrpkits.com


PFR-3 reviews - eham.net
PFR-3 forum reviews - eham.net
I built a PFR-3 - k7og.net

Weber dual bander QRP CW transceiver - RETIRED


Weber dual bander CW QRP transceiver

Any two ham bands of 80, 40, 30, 20, 17 or 15 meters selectable. Built in Iambic keyer with 5 - 40 wpm. RIT (receive incremental tuning), four crystal IF and an audio derived AGC.


RX sensitivity: ~ 0.2 uV minimum detectable signal.
Speaker output: ~ 0.5W.
RIT (receive incremental tuning).
600 Hz audio filter.
AGC: Audio derived.
RX current: ~55mA.


RF out: ~ 5 watts output on all bands with 13.8V supply.
TX current: 550-750 ma on transmit at 5W out. (Current depends on band, higher bands draw more current)


4 IF crystals.
Rotary knob tuning.
DDS VFO drift: ~ 100 Hz for 10 minutes warm up.
Tuning range: ~ 60 kHz.
Tuning rate: 50 or 100Hz (tuning rate is switched by momentarily pushing the tuning knob.)
Built-in Iambic keyer with 5-40 wpm code speed, selectable Iambic A or B modes and two 63 character message memories.
Easy to read four digit LED display with leading zero suppression.
DDS reference frequency and LO frequency can be calibrated.
Size, 4.6� wide, 1.6� tall and 5.5� deep.


The RIT is activated when the tuning knob is pushed about 1 second, until the letter �R� is annunciated, and then released. This toggles the RIT on or off. When RIT is active, the decimal point to the right of the MSD display digit will light. The tuning range of RIT is unlimited and it tunes the whole band. So, it has to turned off after each use.

The last frequency is stored for each band when switching between bands. The frequencies are not stored in a nonvolatile memory, so on power up the default start up frequency is loaded.


Weber dual band transceiver - qrpkits.com
Weber dual bander manual v.1 - qrpkits.com
Weber dual bander manual v.2 - qrpkits.com


Weber Dual Bander - newenglandqrp.org
Weber dual bander manual - w2lj.blogspot.com
Weber dual bander - newenglandqrp.org



An SMD 40m QRP CW transceiver with SMD components. Direct conversion receiver, 1W mosfet PA (at 12V), tuning range at least 10kHz.



Hobo transceiver (German) - qrpproject.de
Hobo manual (German) - qrpproject.de
Hobo Allmode Monoband Transceiver - Support (German) - qrpproject.de
Hobo 80/40/30/20/17/15/12/10 - (German) - qrpforum.de

Here is a page from someone who built the Hobo transceiver.
Building a Hobo transceiver - oe1ifm.at

Mosquita lll

QRP CW transceiver QRP Project Miss Mosquita

QRP Project Miss Mosquita QRP CW transceiver

A 40 meter QRP CW transceiver, 0-5w,single conversion superhet receiver, IF AGC, Currents RX 30mA, TX about 380mA. Optional RIT.

Mosquita III 40m CW Tranceiver 0-5W Basic Kit
Miss Mosquita, the German QRPer female QRP Transceiver
Manual Miss Mosquita-3, Monoband CW Superhet Transceiver 40m FET-Version
Mosquita reviews - eham.net
Miss Mosquita - DL4YHF QRP Homebrew Projects - mydarc.de

Sparrow QRP CW transceiver

Monoband CW transceiver, double VFO A/B, RIT, XIT, split, currents RX 60mA TX 630mA at 5W out (2SC1969).



QRP CW transceiver QRP Project Tramp

QRP Project Tramp QRP CW transceiver

An 8 band CW QRP transceiver. A few mW up to 5 Watt RF, SMD and standard components, two stage AF Filter.

Tramp 8
Tramp 8 manual
Tramp 8 reviews - eham.net

Speaky (QRP) SSB CW PSK transceiver

A 5 Band SSB CW PSK transceiver for the 80, 40, 30, 20 and 15 meter bands. 10W input RF (2 x 2SC1969), DDS/PLL frequency control, VFO tuning range 500kHz, AGC.
A low pass filter and band filters has to be bought separately. Optional digital frequency readout.
Speaky manual

Small Wonder Labs

Two transceivers are available, each for the 20, 30, 40 or 80 meter band. The SW20/30/40/80 is a quite typical qrp transceiver while the Rockmite is a crystal-controlled qrpp transceiver.



Rockmite QRPP CW transceiver

QRPP CW transceiver Small Wonder Labs Rockmite

Rockmite QRPP CW transceiver Small Wonder Labs. Length/width ~65mm

Rockmite is a 0.5W out DC transceiver with crystal control for the 20, 30, 40 or 80 meter bands. It uses one crystal as a front end filter to reduce unwanted SWBC interference. No toroids are used. Automatic T/R offset, a reversible built-in lambic keyer 5-40 WPM. The sidetone is set to 700Hz but can of course be changed.


Rockmite - smallwonderlabs.com
Supplement to Rockmite instructionsRockmite - smallwonderlabs.com
Rockmite Connectors/controls set - smallwonderlabs.com

Reviews and info:

Rockmite reviews - eham.net
Rockmite reviews - eham.net
Construction of a Rockmite - qsl.net/5z4ft
Rockmite build manual - hcra.org
Vxo/RF gain on Rockmite - qsl.net/n0rc
Rockmite enclosure suggestions - n0lx.com
W5USJ Rock-Mite Experiments, VXO and more - qsl.net/n0rc
Rock Mite - w5usj.com
Small Wonder Labs Rock-Mite
The Rock-Mite group - groups.yahoo.com
The Rock-Mite files
The 'Rock-Mite 'A simple CW transceiver for 40 or 20 meters - qrpproject.de/UK
Low-Cost QRP Tranceivers

Rockmite 20

Rockmite 20 instructions - smallwonderlabs.com
Rock-Mite 20m Transceiver - oz1bxm.dk

Rockmite 30

Rockmite 30 instructions - smallwonderlabs.com

Rockmite 40

Rockmite 40 instructions - smallwonderlabs.com
The Rock-Mite 40 - w4hh.org
Rock Mite 40 Complete - n9ik.wordpress.com
The Rockmite - AA5TB
WY3A RockMite 40 - The Rockmite rocks - qsl.net/wy3a

Rockmite 80

Rockmite 80 instructions - smallwonderlabs.com

SW20/30/40/80+ QRP CW transceivers

QRP CW transceiver Small Wonder Labs SW20/30/40/80+

Small Wonder Labs SW20/30/40/80+ QRP CW transceiver

The SW transceivers lack AGC. Superhet with a 3 crystal IF filter.


RIT for the SW transceivers - smallwonderlabs.com

Reviews and info:

SW20/30/40/80+ reviews - eham.net


SW20+ manual - smallwonderlabs.com
SW20 tuning mod
Small Wonder Labs SW20+ - www.w0ch.com
SW20+ Tuning Linearity Modification - www.w0ch.com


SW30+ manual - smallwonderlabs.com


SW40+ lessons - qsl.net/kf4trd
SW40+ manual - smallwonderlabs.com
Small Wonder Labs SW+ 40m QRP Kit - cruisenews.net
SW+40 40-Meter QRP Transceiver - w4hh.org
My Small Wonder + 40 QRP Transceiver -- Modifications -- - w4hh.org
QRP Transceiver Kits: Six Reports from the Field (pdf) - ae5x.com
SW40+ QRP transceiver � Ready for action! - sv3djg.wordpress.com
Who says Ham Radio is expensive? - gritzmacher.net
Small Wonder Labs SW-40+ - movl.net
Small Wonder Labs SW40+ and embedded K1EL K-PCB (K12) keyer


SW80+ manual - smallwonderlabs.com


Yaesu FT-817nd

Yaesu FT-817nd page - qrptransceiver.com

Yaesu FT-817nd HF/VHF/UHF CW/SSB/FM/AM qrp ham radio transceiver

Yaesu FT-817nd HF/VHF/UHF CW/SSB/FM/AM qrp transceiver

(Click on image for 4x image. Click here for a large image.)

Review page 1 - eham.net
Review page 2 - eham.net

Updated december 25th 2019

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