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Looking for UTB-1 or external speaker w/talk back schematic

ShakyMcQuiver

Active Member
Apr 11, 2018
69
57
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I am looking for a schematic (or possibly the module) for the 'UTB-1', (Universal Talk Back) made by RF Limited. The 'module' is obsolete.

I didn't even know these existed until I stumbled on it the other day.
Yes, I know... you don't need a fancy module to obtain talk back, but I like to collect rare or obsolete things like this and maybe try to build them for fun.

From what I gather, it's your basic talk back but it has a low-power audio amp built in. I can see where that would be advantageous if you don't have an amplified external speaker. I've built a few audio amps from time to time. They are pretty simple, but I'd really like to see the UTB-1 schematic and see how they did it.

I can always buy an amplified speaker with the TB feature, but it would be fun to try and make one from my boneyard of old parts.
 

The utb-1 is a nice little add on with a super clean talkback. It's quite a step above the resistor approach as well as an upgrade to some of the older radios that already had built in talkback. They were everywhere from 2000 until above 2010 or so. Should have bought and stashed several of them then.
 
I have a talkback speaker, but it's in storage right now as I'm in the middle of a cross country move. It's fairly simple though as it essentially does the same thing as a resistor, it just moves it inside the speaker and uses a potentiometer to control the volume of the talkback instead of a fixed value resistor.
 
Hmmm.... sounds interesting. I'll have to keep my eye out for one or with any luck I'll run across a schematic. Heck, I'd even buy a broken one so I can trace the board and try to make my own.

I might shoot a message to RF Limited themselves and ask about a schematic, but it's unlikely they'll give one up.
 
By the way, I just found a Talk-Back speaker on Fleabay. It's made by Cobra (model # HG S500).
Got it for $19.99 w/free ship. It's a refurb, but the reviews are good and it comes directly from Cobra with a 2-year warranty, so what the hell. Not the UTB I'm looking for, but it will do for now and it will be an upgrade from the tiny speaker I currently have.

From the research I did, these Cobra speakers normally cost around an average of $40. Some want even more, but I wouldn't pay that much for an extension speaker no matter what bells and whistles it has.

If anything I'll get a look at the how they put it together inside. It's NOT amplified like the UTB-1 board, but you really don't need that unless you have a very noisy cab. Or build a small OP amp or something if you want. Easy enough. I could also plug my CB into my stereo AUX input and enjoy the hash-n-trash at 1500 watts, but I'm not that deaf... at least no yet. Give me a few more years!

I still want to get one of those UTB boards. Getting those obsolete gadgets are like CB crack for me.. lol. So if anyone is willing to part with one, let me know. Even a busted one that I can study.

Thanks!
 

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