[ICOM] 751A Transmit

[GGLL]

	Well, I mean VERY light (I don't recall the grain, but the number was 
high). I've used pencil eraser with certain bandswitch wipers, but with 
other mechanical contacts that had some oxide the only effective way to 
clean them was with the above stated sand paper.

Best regards
Guillermo - LU8EYW.

Jim Miller escribió:
> "with a very light sand paper "
> 
> WOW, seems VERY harsh.  How about just pencil eraser (and not the ink kind).
> We had to do that "in the old days"(1968) on some of the equipment that
> customers had placed in factory environments etc. (humid, DIRTY, corrosives
> in the air).
> 
> 73, Jim
> 
> ----- Original Message ----- 
> From: "GGLL" <nagato at arnet.com.ar>
> To: "ICOM Reflector" <icom at mailman.qth.net>
> Sent: Tuesday, July 24, 2007 7:55 AM
> Subject: Re: [ICOM] 751A Transmit
> 
> 
> Perhaps a general readjustment of screws is in order (for boards,
> specially RF and power amplifier). Unscrew them a little then re-tight.
> In extreme cases, someone add star washers also.
> For the connectors, unplug and sand the pins (exposed ones) with a very
> light sand paper then plug and unplug a couple of times the connector.
> Check antenna connector tightness also.
> 
> Best regards
> Guillermo - LU8EYW.
> 
> EP Swynar escribió:
>> Good Day All,
>>
>> My venerable 751A put up some very strange behaviour yesterday, after
> having sat idle for some 3 months...I wonder if anyone reading this might
> have a suggestion, or two, before I open the rig up later this afternoon?
> Any & all feedback / comments are not only welcomed, they're hereby being
> solicited! Hi Hi
>> Specifically, I fired up the rig to transmit on 40-meters and the power
> output meter showed nearly 150-watts! I reduced the drive control COMPLETELY
> counterclockwise, & it STILL put out the same power...
>> The carrier would stay continuously "on", too, dropping off ONLY when the
> VOX did.
>> This strange condition was evident on both a dummy load, as well as a
> resonant antenna. All "peripherals" were removed, the grounding was
> checked --- status unchanged. I tried it on different bands, but the only
> difference was the power output, which varied from 100- to 150-watts
> (dependent upon the band).
>> Finally, I tried 10-meters & the output suddenly dropped right off to
> zero --- I'm sure I popped the internal fuse with that last test.
>> It would appear that the finals in the rig are somehow "taking off" /
> self-oscillating, for some reason. I have not touched the rig in any way,
> shape, or form, since QRN took over 160-meters here last April.
>> I wonder if, by sitting idle like that, one of the interior connectors has
> somehow oxidized / deteriorated in the humidity of summer...?
>> In any event, I have to get inside to replace the fuse anyway, so I'll
> check those out...but I am curious if anyone else has ever had any similar
> such occurance with their 751A...
>> Thanks in advance, & vy
>>
>> ~73~ Eddy VE3CUI - VE3XZ
>> ----
>> Your Moderator: Dick Flanagan K7VC, icom-owner at mailman.qth.net
>> Icom Users Net: Sundays, 1700Z, 14.316 MHz
>> Icom FAQ: http://www.qsl.net/icom/
>>
> ----
> Your Moderator: Dick Flanagan K7VC, icom-owner at mailman.qth.net
> Icom Users Net: Sundays, 1700Z, 14.316 MHz
> Icom FAQ: http://www.qsl.net/icom/
> 
> ----
> Your Moderator: Dick Flanagan K7VC, icom-owner at mailman.qth.net
> Icom Users Net: Sundays, 1700Z, 14.316 MHz
> Icom FAQ: http://www.qsl.net/icom/
>