fm cb radio info

hi i have been given a 40 ch 27/81 baracudra fm cb radio looking for info on conversion to 10 meters site  thanks for looking paul m0kbd 73s

Hi Paul,

Might be worth a peruse here :-

http://www.g4kfk.co.uk/html/10m.html


I know that nowadays there's also a DDS VFO conversion available so might be worth a search.


The first were common conversions 'back in the day' but I've got to admit I haven't heard much in the way of FM on 10m around my neck of the woods.

Either way, have fun.


All the best,
Victor

The Baracuda is not suitable for 10m conversion, you can put mid block in them but that's about all due to the PLL chip (LC7137) limiting expansion options. Very few FM CB's can be converted, those that can be are usually quite easy to do i.e. Icom ICB1050.

Paul (Rabbi),

Within the link I sent you is a series of links and one of them is this :-

http://www.g4kfk.co.uk/Converting_Unconvertible_CB_Radios_to_10m_FM_SWM_198403.pdf

Which specifically details the issues surrounding the LC7137 and how to successfully (depending on your point of view) convert them. The 74LS92 mentioned is a bit harder to get hold of nowadays (but not impossible) but with a bit of ingenuity you can achieve the divide by six or two with other circuitry.


If you go beyond simple PLL choices, replacing them or 'jumpers' connected to 'programming' pins you can achieve a lot more than realised.

The 'commercial' version of a particular CB Radio DDS VFO only lists certain CB models also, but delve into the technology and you'll come to realise that you can in fact replace the 'PLL' and VFO entirely with such units.

With the awesomely low price of such technology nowadays and a little bit of knowledge about them they are a valuable tool to the modern experimenter......

Up to you of whether it's worth the bother but I know some like the electronics challenge.


A radio is a radio and usually with CB's a little bit beyond Lou Franklin's "Screwdriver Expert's Guide".


All the best,
Victor