EMRFD Message Archive 10772

Message Date From Subject
10772 2015-02-09 12:39:39 shubham VU3SXN & ... requesting support in building a all discreet 27.00MHz CB ssb tran

Subject – requesting support in building a all discreet 27.00MHz  CB  ssb transceiver



i am an electronics engineer living in northern part of  India.
i have more than 10 friends who are swl and are interested in amateur radio as they are from non-technical background it seems quite difficult for them to understand electronics and all radio stuff...but they regularly visit my shack and are highly interested in radio qso over CB radio,
in India CB radio is license free upto 5 watts...
i have a small request from members of this group,

i am planning to make a qrp single frequency or fixed frequency  CB {citizen band} SSB transceiver of 27.000MHz,

this transceiver design is meant for anyone and everyone who want to pick up a soldering iron or wants to experience the taste of ham  radio QRP.

All swl can operate and be on air as its license free

I have a14mhz transceiver design which uses all discreet components like common  npn transistors BC547 and does not use any fancy IC..

I am trying to change this design to 27mhz and in place of vfo I need a fixed frequency oscillator.


The specifications of this transceiver will be –

1.      Easy to make with all discreet components.

2.      No fancy IC to be used.

3.      5 watts ssb output

4.      USB upper side band

5.      Fixed frequency 27.000mhz


I would like to share my design with anyone who is interested in this project,

Please share your ideas and email me..

Email – vu3sxn@gmail.com

shubham tiwari
kc3cwd & vu3sxn

10773 2015-02-09 12:49:57 Jim Strohm Re: requesting support in building a all discreet 27.00MHz CB ssb tr

If this is to be a single-channel 27.000 MHz AM transceiver, you should look at the BITX20 design ... or consider a direct-conversion radio using a 27.000 MHz crystal or a packaged-oscillator on 27.000 MHz and an SA602 / SA612 mixer. 

The IRF510 FET used for the BITX20 won't work on 11 meters, but there are a number of suitable low-power RF transistors or FETs out there that will work.

If you plan to use SSB or have more channels, expect to increase parts count.


10775 2015-02-15 09:25:36 kb1gmx Re: requesting support in building a all discreet 27.00MHz CB ssb
for 27mhz  depends on the IF..

Assuming BITX at 10mhz you need a 19mhz or 39mhz crystal.  19mhz is a somewhat common frequency.

If your IF is different there are other combinations that may work.

 a 7mhz IF and 20mhz local osc
    9Mhz IF and 18mhz or 36mhz local osc (common crystals)
    11mhz if and 16mhz crystal

Not knowing the rules for "CB" in India I cannot comment futher. 
Are you needing excatly 27mhz or to cover frequencies in that range?

 Here in the USA it would be illegal as CB transmitters must be 
"Type Accepted" by our FCC.  Receivers are not so restricted.