Bitx20 Version 3

You can find Sunil's blog page with ordering links at Sunil's blog page


There are new assembly manuals available. These are step-by-step instructions. You can obtain them from:

New Version 3 Exciter Board Assembly Manual

Adjusting the balanced modulator

New Version 3 Linear Board Assembly Manual

Full Resolution Picture of completed exciter board
This is a large format, full resolution picture of a completed board. The file is 2.6 meg in size. This will allow you to zoom in on sections to check the construction.


The old pages below are left for informational purposes. They contain some very useful waveform and construction photos.

After building a Far Circuits Bitx20 and a Hendricks's QRP Kits bitx20a kit, I decided to build another bitx after seeing this posting:

A new batch of Bitx PCB, in glass epoxy ,masked, roller tinned and with
component place-ment is in ready stock for delivery world-wide.
Also available is the pcb for Avala 01 Sdr monoband tcvr.

I am giving a very special discount on the pbc's. To know further about
the discount, kindly send me a mail at suillakhani123@

I sent off my email and received this back:

Dear Leonard,
The Bitx Version 3 PCB is for $10 PCB +Coils+1 No 2570 transistor.
The Avala sdr pcb is for $5.Shipping is extra $ 10.

I looked at this web page to get an idea what the Avala sdr was and decided that I couldn't pass up a deal like this.

After a trip to paypal, the boards for the bitx and the avala were ordered. Soon I received a package in the mail. In it was 3 pcb's. This was the bitx board along with some of the specialized parts. The other boards were the PA board and the Avala board,

There was enclosed, a schematic, a component layout, and a few other pages of documentation.

After examining them, I decided to make an "exploded" layout drawing using a section-by-section approach to the assembly and testing. I will function test each section as it is assembled. This will almost insure that the board will function when everything is completed. I already had an head start on the project as this would be the 3rd Bitx I had built. I already knew what the signals should look like in each stage.

Bandpass filter section

RF amplifier section

RF Driver stage

VFO Section

First Mixer

1st IF Stage


Audio Section

Linear Amplfier