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Need Info On Sears Roadtalker 40 934-38261800

Wire Weasel

Wire Weasel

Senior Moment
Dec 13, 2008
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Hey guys, Trying to tune up a very nice Sears Roadtalker 40 SSB mobile that I acquired.

It's working. Has two typical inductor cans for adjusting power and I've done that. Was at 2 watts and now 2.5 whoopie
SSB only swinging to 8-9 watts whoopie again

Modulation is acceptable, swings over 100% on whistle but poor swing added to AM carrier. There's probably a diode that can be clipped ?? Or a VR adjustment somewhere.

Did the usual searches and can find nothing on this model. Maybe you guys know something.

Made in Japan, may be a Cybernet board. Probably from late 70's / early to mid 80's.

Only number I can find on board is on top solder side and is 590261

Sears model is 934-38261800

Is a nice radio and came to me complete and in box and apparently never hooked up or used. May have been a store demo. Only thing missing is owner's manual. Would like to get it tuned up better. Everything works.

Any help & thanks!!
 

I searched everything I can get my hands on and I can't find that model number anywhere. I found data for model numbers before that one and after that one. Sorry, can you post a picture so we can see what one of those looks like?
 
Okay let's see if this works. Have to resize pics for this forum. Thanks for helping me look.
 
Last edited:
Well it's still no go

None of these components are present.

On Lou's page, he has this radio under chip SM5104

The chip in radio is TC9107P

On the other side of this mods page there are several TC91XXP series chipped radios listed but not the TC9107P

So y'all keep looking and I'm going to start looking for 9107 info

Thanks!!
 
Update...couldn't find anything on board mods using this chip....

And got tired of the runaround (my own) and just did some more tuning and discovery myself. Believe I got it rockin'

The inductor cans are:
T704, T705, T706

AM pwr RT601
SSB pwr RT701

RF meter RT 702
Modulation Light & SWR Light Sensitivity RT002

AM power would peak up to 5.5 watts but with much lower modulation. Set DK to 2.5w however and modulation pegs the meter on my Dosy 4002's and that is with the stock hand mic. SSB is doing 15 watts.

So it's set up and I think I'm going to keep the radio for now as a back up and conversation piece seeing as I have no other back up radio at the moment.

Is anyone interested in having this one? I believe it was a store display model, never hooked up before I got it. 9.99 out of 10 pristine. Flawless faux wood grain covers. The power cord and mic were still sealed in their original bags. Have box that shows some wear but still good. Sears mic in new condition, cord & mounting bracket. Only thing missing was owner's manual.

Make offer ??
 
Interesting that that particular radio has the TC9107P PLL in it. Supposed to have the SM5104 in it. From my notes I have the TC9107P, it's a chip that can't be modified, as it uses BCD ROM, so it's not easy to change the programming thru the pins. Can you provide a nice clear photo of the component side of the board for me? I might be able to locate some adjustments for you, based on what I have in my notes.

(edit) Looks like you found some adjustments, so at least you got a bump in output!

Cheers!
 
Thanks X13, I will take a pic next time inside
photosmile.gif
but can't think of anything else I would want to adjust at the moment. Have it buttoned up and it's sittin' on the end of the radio desk looking pretty and ready to talk.

Might get a chance in a couple of days. Next snowstorm and possibly ice headed to Dixie. If the power goes out I can run this off of batteries
2023.gif
 

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