pc 68 rf gain

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griz
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pc 68 rf gain

#388663

Post by griz »

Hello i pick up a uniden pc 68 radio works good but one problem the rf gain does not work i cleaned it, and tested it but does not work it is wide open all the time anybody have any ideas where to start
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MDYoungblood
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Re: pc 68 rf gain

#388664

Post by MDYoungblood »

Look to see if they turned it into a varible power knob.

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griz
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Re: pc 68 rf gain

#388666

Post by griz »

Everything is hook up like original I checked on another radio
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halfwatt959
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Re: pc 68 rf gain

#388672

Post by halfwatt959 »

check out the cobra 25/ uniden 68 rx mod. Change a transistor or two and 4 diodes. But first 1: do you have any receive at all? 2: does the needle move any? 3: check the squelch pot may be bad plus I don't know where you got the radio how long you've had it or whos worked on it or what mods if any have been done so just guessing at places to start. Could be just a bad diode in the front end. if you look up the shottky rx mod for it you will know which components to check first. Also check the whole board for cold solder joints. 90% of the repairs that I do are cracked solder joints. hope this helps letus know if we can be of further help. 73 halfwatt959
2 and 3/4 DX RADIO CHAOS. Halfwatt959 " I MAY NOT CAN FIX IT BUT I CAN TAKE IT APART"
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griz
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Re: pc 68 rf gain

#388675

Post by griz »

Like I said before the radio works good on tx an rx but the rfgain control is wide open you can not turn it down the control has been cleaned and tested and is good I did the rx mod replaced tr1 d4,6 and I replaced tr5 d1,2,19, 20 no change rfgain wide open can not turn down
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MDYoungblood
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Re: pc 68 rf gain

#388676

Post by MDYoungblood »

griz wrote: February 4th, 2018, 3:00 pm Like I said before the radio works good on tx an rx but the rfgain control is wide open you can not turn it down the control has been cleaned and tested and is good I did the rx mod replaced tr1 d4,6 and I replaced tr5 d1,2,19, 20 no change rfgain wide open can not turn down
Look hard at your work and make sure you didn't cross a solder joint, didn't know you had made a mod, that is the best bet on the problem.

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griz
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Re: pc 68 rf gain

#388677

Post by griz »

the problem was there before the mod was done and the other diodes
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MDYoungblood
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Re: pc 68 rf gain

#388679

Post by MDYoungblood »

You can check the pot with an ohm meter, pop the wires off it and then try a VR to see if it is the control, it will also show you the problems is somewhere on the board receive section close to where the wires connect it.

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