[ICOM] 751A Transmit

[Paul Gates, KD3JF]

Larry, I thought I was the only one who knew that trick with a dollar bill! <g>

Paul, KD3JF

Larry Winslow <larry_w at comcast.net> wrote: A tip from the days of relays...

Use a dollar bill to clean the contacts. It is 
just slightly abrasive & will do a good job of cleaning.

73 - Larry WØNFU
larry_w at comcast.net

At 06:21 AM 7/24/2007, you wrote:

>"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" 
>To: "ICOM Reflector" 
>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/

----
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/