[ICOM] IC-735 VCO Cap Replacement - ???

[AI4WM]

I've read some things on the internet, but I too have never had a problem
with my735. It has been mobile, in the shack and I use it portable.

Then I worked with a fellow who only knew 4 words whenever something had a
problem ' it must need new capacitors.'

Anything can fail, but unless it's an old aluminum capacitor or electrolytic
or some of the old paper capacitors; capacitors under normal use seldom
fail.  Some are better than others and I have replaced one type with a
better type, but in 30 or more years of radio work seldom found bad
capacitors.

Just my 2 cents worth.



On Sat, Feb 27, 2010 at 10:16 AM, Jim Hargrave <w5ifp at gvtc.com> wrote:

> Please enlighten us.
>
> I have owned an IC-735 since 1986 and have never had a problem with the VCO
> Caps.
> Also, I have never seen any reports to that effect.
>
> It has turned out to be one of the most reliable ICOM radios I have owned.
> Mine has been opened only twice in all those years. Once to change the
> battery and once to set the CI-V rate to 9600 baud.
>
>   73's  Jim - W5IFP
>    w5ifp at gvtc.com
>
> > -----Original Message-----
> > From: icom-bounces at mailman.qth.net
> > [mailto:icom-bounces at mailman.qth.net]On Behalf Of
> > harrytheham at verizon.net
> > Sent: Monday, February 22, 2010 9:55 AM
> > To: ICOM Reflector
> > Subject: Re: [ICOM] IC-735 VCO Cap Replacement - ???
> >
> >
> > They did.
> >
> > Harry WE1X
> > Sent from my Verizon Wireless BlackBerry
> >
> > -----Original Message-----
> > From: Doug Renwick <ve5ra at sasktel.net>
> > Date: Mon, 22 Feb 2010 09:24:05
> > To: 'ICOM Reflector'<icom at mailman.qth.net>
> > Subject: Re: [ICOM] IC-735 VCO Cap Replacement - ???
> >
> > Correct me if I am wrong, but I don't believe the 735 had those bad caps
> > that some of the other icoms had.
> >
> > Doug
> >
> > I'll run the race and I will never be the same again.
> > -----Original Message-----
> > From: icom-bounces at mailman.qth.net [mailto:icom-bounces at mailman.qth.net]
> > On Behalf Of Michael, W1RC
> > Sent: February 22, 2010 5:41 AM
> > To: icom at mailman.qth.net
> > Subject: [ICOM] IC-735 VCO Cap Replacement - ???
> >
> > Thanks for the replies and information.  I have performed the
> > replacement with limited success and I am now scratching my head
> > trying to figure it out.
> >
> > When I started this project the radio worked very well on 75 and 40
> > meters.  The problems were with the higher bands.  It was dead above 15
> > MHz.
> >
> > I replaced the plastic PLL trimmer caps C37 C45 C52 and C59 with the
> > ceramic versions purchased from ICOM.  I was able to adjust the two
> > 12 pF caps, C37 and C45 for a reading of 6.5 Volts measured at R108
> > but my meter did not show any change in voltage when the two 6pF
> > trimmers caps were turned.
> >
> > After reassembling the radio it would appear that the original
> > problem has not been resolved.  The radio is still dead above 15 MHz.
> >
> > I did not replace C138.  Since this appears to be a common control I
> > do not think it is the cause of the problem.
> >
> > Most of my troubleshooting and repair experience in over 40 years of
> > hamming is on vacuum tube equipment.  Any ideas or suggestions as to
> > what to look at next will be gratefully appreciated.
> >
> > 73,
> >
> > Michael, W1RC
> >
> >
> > ----
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> > ----
> > 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/
> > To support QSL/QTH.net: http://www.qsl.net/donate.html
>
> ----
> 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/
> To support QSL/QTH.net: http://www.qsl.net/donate.html
>



-- 
73,
Bill
AI4WM