Friday, July 22, 2016

Small Radio --- Big Signal!

A Shirt Pocket SSB Transceiver for 20 Meters!


Several years ago I built a shirt pocket sized SSB transceiver --well actually two of them with the second one being  2X2X4 -- yes that is inches. The overall size was actually dictated by the need to have a front panel. If I had used surface mount it could have been smaller still. The transceiver was the subject of an article in QRP Quarterly. This may be one of the smallest SSB transceivers to be homebrewed. Note for the purists I did not say the smallest!
 
Recently I made a modification to the driver stage which actually was posted on this blog. I now get about two watts out and driving an outboard amp it is good for about 60 watts PEP. Imagine my surprise the other day when ON8KW was calling CQ and I answered him (60 watts) and he came back to me. I got a 5X8 report. Now keep in mind I am using a beam antenna. So once again a good antenna will level the playing field. The LO is a crystal switched two range VXO that covers from 14.162 to 14.188 and 14.194 to 14.225 MHz or roughly about 60 kHz of 20 Meters. The output device is an IRF510.
 
Here are a few photos and today I had about 20 minutes so I built and painted blue a case for the rig. Another cool blue radio! By the way the inspiration for this radio was an article written by Ben Vester W3TLN who built a small 20M SSB transceiver that ran off of 6 VDC and put out 200 MW. The 6 VDC was because he had it installed mobile in a 1959 Volkswagen Beetle where pre-1966 Beetles were 6 VDC.
 
There story here is that you can build an SSB transceiver (large or small) and have meaningful contacts including DX stations. Get off the couch and start building.
 
73's
Pete N6QW
 




8 comments:

  1. Replies
    1. Hi David,

      Thanks for your post. This was a fun project and in the last two days I have had several nice QSO's with the rig. A friend is working on a similar radio but instead of the VXO it will have the Si5351 with a TFT display and the whole radio will be fitted into an Altoids tin. It will be much smaller than this radio. There are but a few surface mount parts in my radio but the Altoids one will be mostly surface mount. My IF is at 4.9152 MHz and the VXO is at 19 MHz.
      Thanks again for your comment.
      73's
      Pete N6QW

      Delete
  2. PETE - That is AMAZING dude! Don't know how you do it. Guess your eyesight is still as good as ever. You are the master!
    G. KJ7UM

    ReplyDelete
  3. Hi Grayson,

    There is a lot of luck, special headband magnifiers and hi intensity lamps involved. Actually was disappointed that it didn't end up smaller. In the article I wrote for QRP Quarterly I mention that had I used more surface mount then it could have been perhaps one half that size. There are now surface mount parts available to do just that. The main IF amps are based on the Plessey circuit as found in EMRFD. For this build hey were done using leaded components. I now have surface mount versions in several transceivers built after this project. So that does make for a challenge in the builds.

    Thanks for your post.

    73's
    Pete N6QW

    ReplyDelete
  4. Hey Pete, the blue would look great on the amplifier too!!

    ReplyDelete
    Replies
    1. That is the Plan!

      Hi Dean, thanks for your post.

      Pete

      Delete
    2. Pretty soon your entire home-brew shack with be blue!!!

      Delete
    3. Actually I am now thinking about a burgundy face with a blue cover. That could be interesting. Yes so many radios to paint so little time.

      Pete

      Delete