Bitx3C With SBL-1 Mixer

Good News for people who are not being able to find ADE-1 ASK mixer and would still like to build the Bitx3C version. We now have a new pcb BITX 3C with SBL-1 Mixer.

The BITX3C with SBL-1  mixer has been tested completely and works great. we shall be providing the PCB soon on our website as well as on our ebay store.

Also is available  the BITX3C SBL-1  AS A KIT or just a pcb to buy.
we shall provide the schematic but no manual, the same Bitx3B manual can be used as most stages are same, leaving the mixers.

Some pictures below of Bitx3C with SBL-1 mixer, i have also mounted the BC549 in the mic pre amp for Q15 as mentioned in the last post.

BITX3C SBL-1 VERSION BUILT UP FOR DEMO

BITX3C SBL-1  PCB 

                 

Dynamic Microphone For Bitx

Lately I have been using a Dynamic microphone for Bitx3B as shown in pictures below.The audio seems to be quite good with it.

One important part that has to be installed in line of microphone is a 3.3uf  Tantalum capacitor, to block the positive 12 volts TX voltage.

Q15 which is 2n3904 in the mic pre amp stage can be changed to  BC549 which is a  low noise VERSION, 
The gain seems to be better then 2n3904 and much better audio quality, it has to mounted in reverse.

New Pictures Bitx3B

For our Bitx3b builders my priority was to build another Bitx3b tcvr , this one with mods on the PA and Exciter Board. The building up of a new Bitx3b ssb tcvr  for 20mt band has been  greatly  rewarding,

Recently i made many contacts on the air with DX and as well as Local stations in India. The stability of PA is excellent with the mod of cutting off  the RX antenna on Transmit, so NO oscillation's from the PA now.

I have attached some pictures of the new build set.

The audio mute board tends to overlap the PA board a bit, this happened because of adding few extra
components to the PA board mod of antenna cut of to RX on transmit. The audio mute board can be mounted with some extra spacers so that the board sits a bit above the PA Board.

A few of you may have problem with the screws size for the case sent, if you have not been able to find screws locally then kindly send me an email for a set to be sent for your Bitx 3b case.

Some pictures which i took of a new Bitx3B build by me recently.

If any one has problem in building the Bitx3b he can be free to email me

best of 73s

Bitx3B Modules Layout And Connections

                       Here is a complete layout of Bitx3B modules

                        Hope it helps all Bitx 3B Builders.

Bitx3B High Resolution Pictures

We are publishing some latest and very clear pictures of high resolution for Bitx3B Exciter-PA-AGC and Audio Mute modules.

Hope it helps the builders with location of part values etc.

Bitx3B Exciter-PA-AGC-Audio Mute

AGC 

Audio Mute

VFO Stage Bitx3B 

Bitx 3B PA

Bitx3B Exciter 

New PCB Bitx3B 3C Exciter And PA

The new printed circuit boards for Bitx3B Bitx3C And PA are ready, these are the boards on which we have done the modifications for RX antenna cut off on transmit mode.

 Good news the kits for Bitx3B and Bitx3C are ready and we shall start selling them from 1 March 2015 on wards. Keep a watch on our website and ebay shop if you would like to purchase the kit.

Published below are a few pictures  of our  new  modified Bitx3B and PA built recently.

 A brief summary of mods done for new boards are as given below.

 1. Bitx3B Exciter,mod done to disconnect of Exciter RX Ant on Transmit.
 2. Bitx3C Exciter, mod done to disconnect of Exciter RX Ant on Transmit.

 New PA Board mod done:

 1. Disconnection of RX Antenna on Transmit at P5.
 2. Selection of 12 or 24 Volts for Final.
 3. Capacitors 0.01 across all four IN4007. 4. IN4007 across both relays.
 4. PC Fan 12 Volts for cooling transistors.

Bitx3B Exciter Silk Screen 

Bitx3B Exciter  Solder Side 

Bitx3B/3C PA Silk Screen 

Bitx3B/3C Solder Side

Bitx3B Built Exciter 

Bitx3B/3C Built PA

stationqrp.com on our blog list

Do you have a blog or website on Ham Radio that you would like us to include on our Blog list, then kindly send us a request with your website or blog URL.

The first request came from stationqrp.com  and we have added this very informative website on our cqbitx blog list.

Kindly also place our blog link on your website once you see your website URL on cqbitx blog.

Thanks and best of 73s

Sunil

Bitx3B 3C kits being packed .

We are pleased to publish this news that a lot of fresh 50 kits for Bitx 3B And 3C are about to be fully packed. The new stock will be sold on our ebay shop and our website.

 http://stores.ebay.com/FUSION-RADIO-VU3SUA

 http://amateurradiokits.in

The new kits include Bitx3b Bitx3C And PA pcb upgraded with some minor but important mods.

                                    The picture below shows some kits in packing stage.

Components Packs for bitx kit 

The Bitx3b/3c case as also ready and ready for sale.

We shall be bringing news soon for opening the sales for this lot of kit.

Thanks and best of 73s

Sunil

New Schematic And Mods Bitx3b/3c

The Bitx3b/3c construction manual is being updated and will be available very soon, we are making some corrections to it, also some mods have been done on the exciter and pa  for both versions.
The main mod being oscillation in PA caused by feedback. We have used a diode switching arrangement to cut of the RX antenna on Transmit, the mods were required on both exciter and pa board.
The new schematic for bitx3b/3c and pa can be download from this link.

https://drive.google.com/folderview?id=0B6TiQJ3zQGGlNWRIcl80RE9WUVU&usp=sharing

The new kits that will be sold now will have these mods done, how ever these mods can also be taken up in the existing pcb's you may have purchased.

The following files will been found with the download link.

1. Bitx3B Exciter Sch, with mod done to  disconnect of Exciter RX Ant on Transmit.

2. Bitx3C Exciter Sch, with mod done to  disconnect of Exciter RX Ant on Transmit.

2. New PA Sch with mod done to:
Disconnection of RX Antenna  on Transmit at P5.
Selection of 12 or 24 Volts for Final.

0.01 Capacitors  across all four IN4007 diodes

IN4007 diodes  across both relays.


New Printed Circuit Boards of Bitx3B, Bitx3C Exciter And PA will have these mods done. The earlier Bitx 3B/3C PA boards can be modified as with above details. The earlier boards can also use relay instead of the diode cut off switch for the Rx antenna as per one's wish as both systems work.

Bitx3C Pictures

Here are some latest Bitx3C pictures .   I hope these pictures help Bitx3B And Bitx3C  builders .

Later I will be posting some Videos  of Bitx3C  .

Best Wishes.