The Defpom Forum, for RadioMods, S&M Software and Music by The Defpom

hello people
does anyone know how to eprom a cobra 148...I did one of these mods over 20 years ago, so memory is a little scratchy to say the least...
I need to know were to get the chips from, how to program them and then how to fit the to the radio....I know its alot to ask, but some one out there must still do them
best regards
Daz

Detailed instructions can be found in the following book.

It's no longer sold, but can be downloaded for free from the original publisher:

http://www.cbcintl.com/docs/EpromBook.htm

Go there, and click "Get it now" at the bottom of the page to download it.

Spectrum communications do Eproms for giving the UK's on Uniden and Cybernet SSB radios.

That book will give you a basic explanation of Eprom programming with many handy tips and circuits to help you do the job but it won't give you the codes for the UK band if that's what your after, you'll have to work them out for yourself.
If you have the knowledge and experience of programming Eproms for CB's then it looks like a good book.
The author knows what he's doing and has written it the way he thinks is a good explanation and easy to understand for the beginner.
You won't find any book in the UK written by an English person that will explain what you need to know the way he does it.
You haven't said if your 148GTL DX is a MK1 or MK2, the MK2 being the easiest one to do.
Dave.

Eprom technology was hot stuff in the 70's and 80's, most of us have moved on since them...

Use a flash based PIC or AVR instead - much easier once you know your way around them... for example, it you want channels 41 to 80 with an EPROM, you'll need the codes for input (switch) and output (PLL) - that's 80 codes all up, just for an extra 40 channels. With a PIC/AVR, just program <original code>+45. One line of code

Other advantages:
1) No need for ultraviolet lights to erase them
2) Can be programmed serially in-circuit
3) Can do other tricks, like:
Scanning/searching/priority or call channel monitoring (dual watch)
Can drive serial PLLs for thousands of channels
No need for lots of switches to select bands / shifts (one extra switch is all you need)
Much easier to obtain parts
Much cheaper (a chip you could do a 1000 channel mod with costs a dollar or 2)
Not limited to 40 channels per "zone" (i.e. you could have one or your ranges as 00 to 99 covering all of 28 Mhz)

We did a Stalker 9 SSB rig with one of these, and a serial PLL scrounged from a 90's era Nokia mobile phone.
It covers 25.000 to 29.999 continuous in 1K, 5K, 10K, or 100K steps. Radio looks original (no extra switches) except that it shows the frequency in freeband mode (display shows Mhz on TX and the first 2 Khz digits on RX.. ie international call shows "55' on receive and "27" on transmit).

Total cost of parts used was under $10.

Hi

Get yourself a pic and code as a look up table - much easier - you could easily
add a LCD for the freq readout , steps etc

MThead