[Icom] 761 Help

Sat, 12 Apr 2003 02:54:15 -0500

Hi George,

Here is the latest on the 761

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?

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 George, W5YR
Sent: Friday, April 11, 2003 12:05 PM
To: [email protected]
Subject: Re: [Icom] 761 Help

Bill, please forgive me if this doesn't come out as I intend, but are you
interpreting "anode" and "cathode" in the conventional-current sense or
otherwise?

Using conventional current, current flows into the anode (arrow)and out the
cathode (bar). The polarities of the voltages at each end are assigned
accordingly. The diode action tends to reduce or block current flow from
cathode to anode.

73/72, George
Amateur Radio W5YR -  the Yellow Rose of Texas
Fairview, TX 30 mi NE of Dallas in Collin county EM13QE
"In the 57th year and it just keeps getting better!"
<mailto:[email protected]>

----- Original Message -----
From: "Clif" <[email protected]>
To: <[email protected]>
Sent: Friday, April 11, 2003 8:23 AM
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/