[MRCA] U-229 & saliva lubrication

[WA5CAB at cs.com]

Rich,

The U-229/U will not plug up if the internal O-ring is dry.  I sold a 
connector to another list member who reported back that it was defective.  So I 
gathered up the remaining ones that I had and a junction box with a U-183/U on it 
and none of them would couple up either.  Took one apart and discovered it 
worked fine with the O-ring removed.  Finally had one of those Duh! moments and 
got out the OD tube of special purpose underwater mine O-ring grease and that 
fixed the problem.

On the wiring of the U-183 itself, I don't have the -35 but I can't believe 
that all five contacts are tied together, nor that the other half of the 
circuit is the outer shell. Perhaps you are looking at the schematic of the RT-654 
rather than that of the RT-654A.  The former has a JK-34-A (standard 1/4" phone 
jack for PL-55 plug) for audio out.  Standard wiring to the U-183/U would be 
Ground to A and Receive Audio to B.  E may or may not be tied to the key line.

In a message dated 2/1/2006 10:21:23 PM Central Standard Time, 
richard.arland at verizon.net writes: 
> Thanks guys! Great idea. However, I think I'll stick with the silicone. Any
> particular brand? How about using something like Lubriplate (tm) which is
> silicone based and I happen to have that stuff on hand?
> 
> I,  like Philip, KA4KOE, thought that the U-229 would be much easier to plug
> up to my TRC-77A's audio output jack than it is. Initally I was hesitant to
> try any type of lubricant since I didn't know how it would affect the
> opreation of the rig or if it would possibly degrade or ruin the connector
> itself.
> 
> Incidentally, I have a couple of spare U-229s and want to make an audio
> patch cord using one of them to interface my W3NQN passive AF filter to the
> 77A. Having constructed a 6 ft AF patch cord with a 1/8" (3.5 mm) stereo
> jack on one end and the U-229 on the other I get no audio from the radio at
> all after hooking it up to the rig!. The schematic from the TM
> 11-5820-473-35, Figure: 7-6 (fold out schematic of the rig) indicates all
> five pins on the U-183/U audio jack on the front of the TRC-77A are tied
> together and are "hot" with receiver audio, with the grou nd side of the AF
> circuit going to the shell of the audio jack.
> 
> After afixint the U-229 plug to the patch cord, I reassembled the U-229
> according to specs. The U-183/U jack and U-229 plug mate together like
> normal, however, I get no audio when I attach a set of Sony Noise Cancelling
> headset 68 ohms, not 600) to the end of the patch cord; not even any low
> level audio. There is no audio getting thru the filter to the headset when I
> place the NQN AF filter in series between the rig and the headset. Am I
> doing something terribly wrong? Continuity checks done on the AF patch cord
> shows that there are no shorts bewteen any of the pins on the U-229 and the
> shell of the connector. I am beginning to think that the schematic is drawn
> incorrectly, OR Depot Level maintenance rewired the U-183/U jack to comply
> with a modification and neglected to document the change in the TM.
> 

Robert Downs - Houston
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MVPA 9480
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