[ICOM] 751A Transmit

[GGLL]

	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
> ----
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