Correct Sch Bitx3B AGC

Kindly find the correct Bitx3B AGC  complete details of schematic, silkscreen , components layout.

I am extremely sorry that we had earlier uploaded and sent a wrong schematic of the Bitx3B AGC.

Note:R16  Value 10k to 15k.  10k works ok

Uploading Pictures And Posting On CQ Bitx

We are inviting Bitx version 3 builders to contribute with article and pictures of their built Bitx tcvr on Cq Bitx blog .

To seek an invitation to  Upload  pictures  and Post on our blog , kindly send a scanned picture of your license to establish the authenticity of your Ham Radio Profile, with your name, email etc

The invitation to post pictures and write on CqBitx will be sent as soon as we have your profile details.

Kindly email me at vu3sua@gmail.com for your request.

Best of 73s

Sunil  VU3SUA

New Avala PCB

If you are looking to build the Avala 01 sdr tcvr we now have the PCB's for sale.
The present Avala PCB is made with all corrections as per original circuit and with tinning and masking, and a better silk screen  of the pcb.

The PCB will be available from our website http://amateurradiokits.in and also from our ebay shop.

AVALA 01 SDR PCB WITH NEW SILKSCREEN

                                  

AVALA 01 SDR PCB WITH MASKING

LABELS FOR JUMPER CONNECTIONS ON PCB

AGC Pictures

To help in construction the AGC circuit used in Bitx3B or if used in any other receiver , some pictures are being published here. One resistance that was sitting between preset and lm324 is 10K , the value is now shown in the AGC pcb image file

ADE-1 Mixer for Bitx Version 3

Information is being provided as how to connect the ADE-1 Mixer for the older version of Bitx3 And also for Bitx Version 3B. The Bitx Version 3 C has already been updated with ADE-1 Mixers.

BITX VERSION 3 B WITH ADE-1

Bitx Version 3C

For those of you wishing to build the Bitx 3 with ADE-1 Mixers the good news is that the PCB's are ready for the Bitx Version 3C.   There have been no other changes in Bitx 3C

The Bitx3C has been tested and performance is good. I shall publish a video soon of a working set.
 Published below are two pictures of Bitx3C.

Bitx Version 3C Solder Side with ADE-1 Mixers

                                        

Bitx Version 3C Components Side 

      The Bitx Version 3C PCB And kit will be available by next week onwards.

Bitx3B VFO complete band coverage with zero drift

A new video of Bitx3B is being shown here, which has the following improvement:

1. Full coverage of 20Mt band from 14.000MHZ to 14.350MHZ
2. Zero drift with varicap tuning diode.

The varicap is 1SV149  .   They work up to a maximum of 10V biasing and capable of a C max of 500pF at 1V bias. so we can manage from 8V regulator easily.

This device was suggested to me by my good friend MVS  Sarma from Hyderabad. India.
After trying this device i did not think twice by replacing it with MV209.

So now we have a very stable VFO with BITX3B giving a complete band coverage, who wants a DDS anyway for a mono  band tcvr ........

      VIDEO OF BITX 3B  FULL COVERAGE WITH STABLE VFO  WITH NO DRIFT