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cb radio from scratch ?
- Thread starter minitrucker
- Start date
lords
Active Member
I did. The design was an on going project over many years.
It started with just a crystal locked radio, but then it grew, and grew out of control. Orginally it was AM, then I put in FM.
SSB was too hard for a long time. I had a DBM + BFO for DSB suppressed carrier, then I learned how to build crystal filters and had crystals made for the job.
In the end the PLL was controlled by my CPM computer. The PA stage just got bigger and bigger, eventually I had to put fans on it. I sold it for $500 back in the 80's and used the money to buy me a fancy ham radio.
It wasn't long before before the urge returned to build radios again.
Building a radio from scratch is certainly not for the faint hearted. Start simple and modify modify and modify.
The end result will look like the dog's breakfast, but it out perform anything you can buy on the shelf
If you're looking for some radio kits.
DIck Smith Electronics here in Aus had a HF kit, which was easy to build specifically to CB, they also did a UHF 70cm radio "Explorer" which could also be built specifically for UHF CB (477MHz) and would be very easy to build as an FRS or GRMS radio.
You can still find plenty of them second hand on vkham.com from time to time. They often turn up at local field days for $20.
This is an example of one of my heavily modified radios.
It ended it's life as a 27MHz CB, the mixer stages were discarded. The PLL is an 02A, but the divider chain is extended to cover the entire 70cm band. New multipliers and mixers and filters were added. FM was added. Finally a PA was recovered from an old UHF radio lying around. A short cut from using a couple of new transistors and making up a new board.
Anyhow... here's some pictures to inspire or discourage
http://home-and-garden.webshots.com/photo/2856450210048941318IVkeRf
http://home-and-garden.webshots.com/photo/2776001770048941318hGCXgL
It started with just a crystal locked radio, but then it grew, and grew out of control. Orginally it was AM, then I put in FM.
SSB was too hard for a long time. I had a DBM + BFO for DSB suppressed carrier, then I learned how to build crystal filters and had crystals made for the job.
In the end the PLL was controlled by my CPM computer. The PA stage just got bigger and bigger, eventually I had to put fans on it. I sold it for $500 back in the 80's and used the money to buy me a fancy ham radio.
It wasn't long before before the urge returned to build radios again.
Building a radio from scratch is certainly not for the faint hearted. Start simple and modify modify and modify.
The end result will look like the dog's breakfast, but it out perform anything you can buy on the shelf
If you're looking for some radio kits.
DIck Smith Electronics here in Aus had a HF kit, which was easy to build specifically to CB, they also did a UHF 70cm radio "Explorer" which could also be built specifically for UHF CB (477MHz) and would be very easy to build as an FRS or GRMS radio.
You can still find plenty of them second hand on vkham.com from time to time. They often turn up at local field days for $20.
This is an example of one of my heavily modified radios.
It ended it's life as a 27MHz CB, the mixer stages were discarded. The PLL is an 02A, but the divider chain is extended to cover the entire 70cm band. New multipliers and mixers and filters were added. FM was added. Finally a PA was recovered from an old UHF radio lying around. A short cut from using a couple of new transistors and making up a new board.
Anyhow... here's some pictures to inspire or discourage
http://home-and-garden.webshots.com/photo/2856450210048941318IVkeRf
http://home-and-garden.webshots.com/photo/2776001770048941318hGCXgL
lords
Active Member
wow!!!
i am most impressed!!!
trash, hats off to you buddy; you really must know your stuff.
loosecannon
i am most impressed!!!
trash, hats off to you buddy; you really must know your stuff.
loosecannon
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