Around I became aware of the BITX20 designed by Ashhar Farhan. The BITX20 is a low technology transceiver designed to use “simple” components and is easily adapted to other bands, I quickly manufactured a variant for 80M (version 1). The radio presented here is a development of that; now at version 3. Bitx20 and other Qrp projects. Cqbitx was started in 31st July 2000. That is 10 years now. We have contributed to the cause of Bitx and have never mentioned that Bitx has to do anything with our contribution towards the design. We have helped more then 300 members with Bitx 3 Kit as by Ashhar Farhan and Mods by VU3WJM. DG1NPJ Juergen Pfeifer From Germany has sent us information for the AGC, CW Keyer and Soundcard details that he has incorporated in his Bitx Version 3. Here are the details so that it would help all members in constructing these mods for the Bitx. The CW Modul i have found by Google looking for schematics of Bitx20, it works, but the Audio. The VIZIO Support homepage provides the latest trending support topics and support videos, user manuals, product registration, along with tech specs and troubleshooting steps.
BITX20 by Hendricks Kits
This little board should have been a ‘work first time’ too…but it isn’t.
The BITX20 was originally designed by Ashar Farhan VU3ICQ, and the aim was to use common, low cost parts. This would mean that radio amateurs in poorer countries could build a working SSB transceiver and work the world on 20m. His website is here.
Sunil Lakhani VU3SUA, made available some PCB’s, so those who didn’t want to build ‘dead bug’ style or make their own boards, didn’t need to. Here is Sunil’s website, but he sometimes sells on eBay too.
I opted for the version by Hendricks QRP Kits in the states; details here. At that time you could buy just the PCB and components kit for about $60…now, you have to buy a complete kit including case and frequency counter; $180 before carriage and UK import taxes.
Hendricks BITX20
I found the board quite fiddly to assemble…I don’t really know why, it just was. Some of the semiconductors supplied did not match the manual and I had to look up which one was the equivalent; not a major hardship but they could have listed the options in the manual.
Bitx20 Version 3 Manual
As it is now, I have the receiver working but deaf as a post with the bandpass filter in circuit; thankfully my spectrum analyser will help with that. There are no incorrect parts or bad joints…so who knows.
Bitx20 Version 3 Manual Download
Bitx20 Version 3 Manual Pdf
The transmitter PA also takes off when you try to set the bias current…apparently there’s a mod for this. Would I build another? No, I’d go for the ILER-20 which is cheaper and almost certainly a ‘work first time’.