[NLRS] "Fixing" a 2m TR-751A with no audio

[Dr. Gerald N. Johnson]

Roughly the same thing works for the RF gain pot when it goes open. 
Except that it gives maximum gain with a resistance of 10K. So I 
soldered a 10K 0805 surface mount resistor between the traces. On the 
squelch pot I wouldn't cut the wires, just bridge the pot pins with a 
blob of solder which can encase a short bit of most any size copper wire 
smaller than 14 gauge.

73, Jerry, K0CQ

On 7/14/2013 4:37 PM, w0zq at aol.com wrote:
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> At our tune up meeting yesterday several op's commented on having a TR751 2m rig where they have to "giggle" the squelch pot to get audio out.   Here was my fix.  Remove the bottom cover.  Be careful with the speaker leads as you remove the bottom cover ... you can disconnect the speaker if you need to.  With the rig upside down and with the knobs facing you, the on/off volume squelch pot will be on the far right side, top, and close to you.  There is a little circuit board that this pot is mounted to with a 8 wire connector .... the connector has silk screening on the board labeling it as J9.  If you look closely at the silk screen labels on this small PC board you will see the follow labels for each of the eight wires - SB, S, A1, E, E, A2, SQ1 and SQ2.   According to the schematic, SQ1 and SQ2 are the in/out to the pot for SQL level control where the pot functions as a simple variable resistor.  On my unit SQ1 and SQ2 were blue and yellow wires and closest to the front 
panel.  The fix is simply to cut these two wires and solder them together which bypassing the SQL pot and makes the radio functional again.   If you feel you want a SQL, then the squelch pot is a 50k ohm pot and you could perhaps side or top mount one, etc.   For use as an IF rig, SQL is not a required function.
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> 73, Jon
> W0ZQ
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> See you at the 47th Central States VHF Society Conference, July 25–27, in Elk Grove Village, IL
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