[ICOM] IC-745 & IC-EX242 FM board

[Frank A. Ellis]

Reid,

The symptom is fluctuating, intermittent, or low
output power on transmit. Touching or cycling the COMP
Switch may restore the output, or make it more
intermittent. The 740 COMP Switch is used to route the
actual 9 MHz IF signal on transmit, and when the
switch gets dirty or corroded, problems develop with
output level.

Although very similar to the 740, the 745 does not
suffer from this problem, as it was corrected during
the 745 design.

73, Frank W3UHF




--- Reid Bishop <rbish at attglobal.net> wrote:

> Mike,
> 
> I don't think this is an issue with the speech
> compressor switch.  I have
> noticed no issues with this switch to date, and it
> is functioning fine when
> the FM module is not plugged in.  What are the
> classic symptoms of a bad
> speech compressor switch?
> 
> Thanks for your input!
> 
> Reid - KC0TAR
> 
> -----Original Message-----
> From: icom-bounces at mailman.qth.net
> [mailto:icom-bounces at mailman.qth.net] On
> Behalf Of Michael P. Olbrisch
> Sent: Tuesday, January 11, 2005 6:46 PM
> To: 'ICOM Reflector'
> Subject: RE: [ICOM] IC-745 & IC-EX242 FM board
> 
> 
> 
> Although the problem seems to stem from the FM
> module, dig a bit deeper.
> Other than the installing and removing of the FM
> board, your symptoms
> describe exactly what is the number 1 problem of the
> 740 series.  That is a
> bad speech compressor switch.  When I sold my 740 I
> installed a new switch
> and sent along a spare - just in case.
> 
> If it is your switch, make every effort to just
> replace it.  Cleaning it at
> best is an iffy proposition - it just doesn't work.
> 
> GL.
> 
> 
> Mike.  KD9KC
> 
> My E-mail address: mike2004 at elp dot rr dot com
> Ham Radio page: http://www.qsl.net/kd9kc/
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> 
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> 
> Holder:
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> 
> U.S. Army Retired.
> 
> Freedom is expensive.  Those who are not willing to
> pay the price ultimately lose everything.
> 
> 
> 
> > -----Original Message-----
> > From: icom-bounces at mailman.qth.net 
> > [mailto:icom-bounces at mailman.qth.net]On Behalf Of
> Reid Bishop
> > Sent: Wednesday, January 12, 2005 1:19 AM
> > To: 'ICOM Reflector'
> > Subject: [ICOM] IC-745 & IC-EX242 FM board
> >
> >
> >
> > Hi,
> >
> > I recently plugged a never-used IC-EX242 FM board
> into my IC-745.  
> > Seems to work great, but I did end up with one
> issue.  When this board
> > is plugged in,
> > the 745 refused to output any power whatsoever in
> SSB, RTTY,
> > or CW mode.
> > All the relays click, the TX lamp lights up, but
> absolutely
> > zero output.  TX
> > on FM works fine.
> >
> > Once I pulled the IC-EX242 board out, then SSB,
> CW, and RTTY modes 
> > worked fine again.  I plugged the EX242 back in,
> carefully following 
> > the instructions just to be sure, and it still had
> the same problem.
> >
> > Any thoughts?
> 
> 
> ----
> Your Moderator: Dick Flanagan K7VC,
> icom-owner at mailman.qth.net Win a new
> Icom IC-756 PRO III and help QSL/QTH.net Details at:
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> 
> ----
> Your Moderator: Dick Flanagan K7VC,
> icom-owner at mailman.qth.net
> Win a new Icom IC-756 PRO III and help QSL/QTH.net
> Details at: http://mailman.qth.net/
> 



		
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