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President Adams slide mod/F.A.O Zodiac

Posted: Sunday 13th Jul 2008, 0:39
by DIRTY HARRY
Hi Zodiac or who ever is reading this, thought i would start a new thread for the Adams mod talk etc since we were talking about it in the wrong area before, right Zodiac i tried your slide mod & yes it went about 3khz either side of the 12 o'clock position, any idea's on how i could increase the slide for 5+ khz either side? Another thing i have noticed is that it likes to gradually drift off frequency on ssb even if the radio has been on for hours , could it be the 7 or 11 mhz crystals for usb?Any idea's on what it could be or how to cure this & give it better stability much appreciated,Cheers,Shaun :D

Re: President Adams slide mod.

Posted: Monday 14th Jul 2008, 20:27
by Rick
Is the drift on all modes? or just SSB?
The drift may not be easy to spot no AM but you should also check that it is ok.

Hook-up frequency counter to TP6 and TP8 to see which one is on the move.

Where did you pick-up the supply for the voice lock?

Common faults are: Bad supply, Varicaps, caps out of spec, and so on.
As the radio is now very old it could be a number of faults

One of the easy way to find the fault is to but the voice lock back to stock. Once back to stock check for drift.

To increase the slide range try changing the varicaps, but I would fix drift fault first.

Posted: Monday 14th Jul 2008, 21:04
by DIRTY HARRY
Hi Rick :D , yes i have already put the clarifier back to being a stock one, the drift is there still on ssb,i have exchanged the ssb crystals out of my realistic trc-449 as they are the same but the problem still persists, any idea where else i could try,cheers mate,Shaun :D

Re: President Adams slide mod.

Posted: Monday 14th Jul 2008, 22:18
by Rick
Hook-up frequency counter to TP6 and then to TP8 to see which one is on the move, let us know which one is on the move.

Posted: Monday 14th Jul 2008, 22:27
by DIRTY HARRY
both drift,but this is an irregular thing,sometimes its stable for hours.

Re: President Adams slide mod.

Posted: Monday 14th Jul 2008, 23:23
by Rick
All Test on channel 19.
What is the frequency at TP6? and now much is it moving?
What is the frequency at TP8? and now much is it moving?

Posted: Monday 14th Jul 2008, 23:32
by DIRTY HARRY
Hi, yep its drifting about 1khz on both, (when it does)

adams gif

Posted: Monday 14th Jul 2008, 23:58
by warhorse
just got shot of an adams 80 ch mint nice had many

try this link checked for virus, trojans all clear ziped. quality not the best i do have the diagram but no scanner. ie 51 transistors,8field effect transistors 9 intgrated circuits 87 diodes 4 leds.-am 4watts-3amp 12watts pep-2.5amp.

http://www.citizensband.radiouk.com/xtr ... name=adams

Posted: Tuesday 15th Jul 2008, 0:09
by DIRTY HARRY
Cheers for that warhorse, but i already have access to all the info etc,thing is i would'nt know where to start as its all above my head,thats why im here for idea's as to what the problem could be,cheers again,Shaun :D

Re: President Adams slide mod.

Posted: Tuesday 15th Jul 2008, 0:37
by Rick
All Test on channel 19.

The question I ask was
What is the frequency at TP6?
Now much is it moving?
What is the frequency at TP8?
Now much is it moving?
Also check the frequency at TP9?
Now much is it moving?

I think you maybe guessing about TP8, as it is not possible for it to move that much.
I cannot help you if you do not give me the right information.

Posted: Tuesday 15th Jul 2008, 0:47
by DIRTY HARRY
think i will get back to you on this when i have a more accurate frequency counter in my possesion,also i would have to measure the amount of drift over a period of time,as it just does not occur all the time,cheers anyway.

Posted: Tuesday 2nd Sep 2008, 17:09
by Uncle Ray
Hi mate.

This should / will fix your problem


http://www.cbtricks.com/radios/cobra/13 ... tb1216.pdf


The same for the TRC449.

Cheers.