[Icom] 761 Help

Sat, 12 Apr 2003 15:48:22 -0500

Check the BPF filters on the RF unit for shorted diodes causing more than on
to be on at a time.

Clif Holland,  KA5IPF
AVVid
Authorized Kenwood and Icom Service
www.avvid.com
1-800-214-5779
972-554-6801
----- Original Message -----
From: "wjdiamond" <[email protected]>
To: <[email protected]>
Sent: Saturday, April 12, 2003 2:46 AM
Subject: RE: [Icom] 761 Help

> Hi Clif,
>
> Well here is the latest..
>
> After changing the VCO trimmers and lytics, the receiver is working fine.
> The transmit works fair in SSB with about 50 watts output with the
> compressor off and nothing at all with it on.
>
> I have about 4 watts out on RTTY and nothing on CW, AM.
>
> I have changed Q 14 on the RF board as well as some .1 caps.  The voltages
> are correct on the various diodes.
>
> I have checked the voltages on the PA unit and they are all correct.
>
> I traced the signal with a scope from J 8 on the RF board to the
predriver,
> drivers, and the outputs and each stage increases on the scope.
>
> I still keep thinking that the problem is low output at J 8 on the RF
> board.  What is the RF level that should be at J 8?
>
> Any good ideas would be appreciated.
>
> 73
>
>         William J. Diamond (Bill)
>         Rogers, Arkansas USA
>         [email protected]
>
>         Ham Radio Operator WR�T
>       Flying The Flag Long Before
>             It Was Popular
>    Please Visit My New Icom Radio Page
>
>  http://pages.sbcglobal.net/wjdiamond/index.html
>
> -----Original Message-----
> From: [email protected] [mailto:[email protected]]On
> Behalf Of Clif
> Sent: Friday, April 11, 2003 2:07 PM
> To: [email protected]
> Subject: Re: [Icom] 761 Help
>
>
> Look closely at C174, C179.
>
> Clif Holland,  KA5IPF
> AVVid
> Authorized Kenwood and Icom Service
> www.avvid.com
> 1-800-214-5779
> 972-554-6801
> ----- Original Message -----
> From: "wjdiamond" <[email protected]>
> To: <[email protected]>
> Sent: Friday, April 11, 2003 12:02 PM
> Subject: RE: [Icom] 761 Help
>
>
> > Hi Cliff,
> >
> > Thanks.   From the amount of previous soldering on the RF board in the
> area
> > of the diodes someone has been in there before searching for the
problem.
> >
> > At this point, I am about to replace all the associated diodes with the
> > correct ones from Icom as I have no way to tell if the right diodes were
> > even installed by whomever.
> >
> > I suspect that several people have tried to fix this one.
> >
> > 73 to all
> >
> >         William J. Diamond (Bill)
> >         Rogers, Arkansas USA
> >         [email protected]
> >
> >         Ham Radio Operator WR�T
> >       Flying The Flag Long Before
> >             It Was Popular
> >    Please Visit My New Icom Radio Page
> >
> >  http://pages.sbcglobal.net/wjdiamond/index.html
> >
> > -----Original Message-----
> > From: [email protected] [mailto:[email protected]]On
> > Behalf Of Clif
> > Sent: Friday, April 11, 2003 8:24 AM
> > To: [email protected]
> > Subject: Re: [Icom] 761 Help
> >
> >
> > The schematic is correct, figure out why yours is wrong.
> >
> > Clif Holland,  KA5IPF
> > AVVid
> > Authorized Kenwood and Icom Service
> > www.avvid.com
> > 1-800-214-5779
> > 972-554-6801
> > ----- Original Message -----
> > From: "wjdiamond" <[email protected]>
> > To: "Icom@Mailman. Qth. Net" <[email protected]>
> > Sent: Thursday, April 10, 2003 10:52 PM
> > Subject: [Icom] 761 Help
> >
> >
> > > Hi Gang,
> > >
> > > Now I am really perplexed.  The reading that I get on each side of
> Diode
> > D
> > > 47 are exactly opposite of what they should be.
> > >
> > > According to Icom and the manual the cathode side should read 9.4 RX
> and
> > > 9.7 TX
> > >
> > > The Anode side should be 8.8 RX and 13.8 TX
> > >
> > > Mine reads the exact opposite I guess the black band is still the
> cathode
> > > today as in many years ago. I always considered the Anode side to look
> > like
> > > an arrow on the schematic.
> > >
> > > This is a weird diode also it is a M 1204 and I cannot find a cross
for
> > it
> > > anywhere.
> > >
> > > What am I missing??
> > >
> > > Thanks
> > >
> > >         William J. Diamond (Bill)
> > >         Rogers, Arkansas USA
> > >         [email protected]
> > >
> > >         Ham Radio Operator WR�T
> > >       Flying The Flag Long Before
> > >             It Was Popular
> > >    Please Visit My New Icom Radio Page
> > >
> > >  http://pages.sbcglobal.net/wjdiamond/index.html
> > >
> > >
> > > ----
> > > Your Moderator: Dick Flanagan W6OLD, [email protected]
> > > Icom Users Net: Sundays, 1700Z, 14.315 MHz
> > > Icom FAQ: http://www.qsl.net/icom/
> > >
> >
> > ----
> > Your Moderator: Dick Flanagan W6OLD, [email protected]
> > Icom Users Net: Sundays, 1700Z, 14.315 MHz
> > Icom FAQ: http://www.qsl.net/icom/
> >
> >
> > ----
> > Your Moderator: Dick Flanagan W6OLD, [email protected]
> > Icom Users Net: Sundays, 1700Z, 14.315 MHz
> > Icom FAQ: http://www.qsl.net/icom/
> >
>
> ----
> Your Moderator: Dick Flanagan W6OLD, [email protected]
> Icom Users Net: Sundays, 1700Z, 14.315 MHz
> Icom FAQ: http://www.qsl.net/icom/
>
>
> ----
> Your Moderator: Dick Flanagan W6OLD, [email protected]
> Icom Users Net: Sundays, 1700Z, 14.315 MHz
> Icom FAQ: http://www.qsl.net/icom/
>