[Icom] IC-751A - failure of audio related capacitors

Thu, 16 May 2002 10:28:46 -0400

Jim,
The caps he is referring to are the VCO trimmer caps.  These suffer from
what I believe is called metal migration and with time will change value.
This puts the VCO out of range for each band segment the particular cap
covers and the symptoms start with raspy sounding audio on RX and TX.  With
more time, you will loose the band segment completely.  The fix is to
replace the caps or simply just do what I have done with a 751 for years, is
to open up the rig and using a plastic trimmer tool, adjust the caps back
and forward until you find the new middle range of the cap and just leave it
there.  Worked well for me.  Sometimes the new range will hold for a year or
more, other times only a few weeks until the caps settle down.  No special
equipment, I just listen to the raspy sounds or loss of range completely,
move the other direction to hear the same thing, and set the cap in the
center of the end points.
Or, just ship it back to Icom, they will fix it up for around $75.
Bruce K1XR

----- Original Message -----
From: "Jim Shaw" <[email protected]>
To: <[email protected]>
Sent: Thursday, May 16, 2002 10:06 AM
Subject: [Icom] IC-751A - failure of audio related capacitors

> Does anyone have the procedure for replacing the audio related capacitors
in
> the IC-751A.  I don't currently have a problem with my IC-751A but the
other
> day I was in an Ham Radio Outlet (admiring the 756PROII) and asked the
> representative what his perceptions were about the IC-751A.  He advised me
> that, although the IC-751A is highly reliable in his opinion, his
perception
> of the most common failure in the IC-751A involves the capacitors related
to
> the audio (both tx and rx). He said the symptom is distorted audio on both
> tx and rx.
>
> So I would like to know how to address the situation when/if the failure
of
> these caps happens in my IC-751A.  Does anyone have advice on how to deal
> with this situation if it should occur?
>
> Regards
> Jim Shaw
> [email protected]
> www.ShawResources.com
> 408-973-1608
>
> -----Original Message-----
> From: [email protected] [mailto:[email protected]]On
> Behalf Of Jim W7RY
> Sent: Wednesday, May 15, 2002 7:59 PM
> To: [email protected]
> Subject: [Icom] Icom Quality Control - Original VCO caps
>
>
> I forgot to mention, my 751A still has the original VCO caps in it. Works
> fine. use it every day.
>
> 73
> Jim W7RY
>
> ----- Original Message -----
> From: "Jim W7RY" <[email protected]>
> To: <[email protected]>
> Sent: Wednesday, May 15, 2002 7:47 PM
> Subject: Re: [Icom] IC-706MKiiG vs. FT-100D
>
>
> > There is a big difference between a quality control problem and
defective
> > parts that show up YEARS later.
> >
> > Quality control refers to:
> >
> > Does it work out of the box (off the assembly line)?
> > Do ALL of them work out of the box (off the assembly line) ?
> > What is the warrantee return rate ?
> >
> > My guess it was pretty small rate of warrantee problems if any.
> >
> > Bottom line, the quality control was GREAT!
> >
> > If you want to talk quality control, you need to analyze what is
analyzed
> > when quality control is analyzed!
> >
> > 73
> > Jim W7RY
> >
> > ----- Original Message -----
> > From: "Tony Hwang" <[email protected]>
> > To: <[email protected]>
> > Sent: Wednesday, May 15, 2002 6:46 PM
> > Subject: Re: [Icom] IC-706MKiiG vs. FT-100D
> >
> >
> > > Hi,
> > > I'd think the plastic trimmer on PLL ckt, a quality problem.
> > > 73,
> > > Tony, VE6CGX
> > >
> > > David Rogers wrote:
> > > >
> > > > The statement was that the Yeasu was having a quality control
problem
> > > > (frankly, I think it is several basic design flaws, but won't argue
> the
> > > > point).  No one accused Icom of having a quality control problem.
> > > >
> > > > David, WA7ZYQ
> > > >
> > > > ----- Original Message -----
> > > > From: "anthony costa" <[email protected]>
> > > > To: <[email protected]>
> > > > Sent: Wednesday, May 15, 2002 6:16 PM
> > > > Subject: Re: [Icom] IC-706MKiiG vs. FT-100D
> > > >
> > > > > quality control is NOT a problem with icom.i have a 756 pro and a
> > > > ic-718.the
> > > > > 718 is one fabulous radio.If you can scratch up 550.00 buy this
> rig.it
> > is
> > > > > hanging close to my kenwood ts-570d/g.that's saying a lot,the 570
is
> > no
> > > > > slouch!
> > > > >
> > > > > anthony k2vi
> > > > > ----- Original Message -----
> > > > > From: "David Rogers" <[email protected]>
> > > > > To: <[email protected]>
> > > > > Sent: Wednesday, May 15, 2002 9:43 AM
> > > > > Subject: Re: [Icom] IC-706MKiiG vs. FT-100D
> > > > >
> > > > >
> > > > > > This is very well put, and I agree completely.
> > > > > >
> > > > > > David, WA7ZYQ
> > > > > >
> > > > > > ----- Original Message -----
> > > > > > From: "John L Merrill" <[email protected]>
> > > > > > To: <[email protected]>
> > > > > > Sent: Wednesday, May 15, 2002 4:11 AM
> > > > > > Subject: Re: [Icom] IC-706MKiiG vs. FT-100D
> > > > > >
> > > > > >
> > > > > > > Yaesu/Vertex is having is having reliability/quaulity control
> > problems
> > > > > > > particularly with the MkV and 100D. You might want to go to
> > > > www.eham.net
> > > > > > >   and read some of the reviews from users. The 100d is
probably
> a
> > > > better
> > > > > > > radio when it works.
> > > > > > >
> > > > > > > John N1JM
> > > > > >
> > > > > >
> > > > > > ----
> > > > > > Your Moderator: Dick Flanagan W6OLD, [email protected]
> > > > > > Icom FAQ: http://www.qsl.net/icom/
> > > > > >
> > > > >
> > > > > ----
> > > > > Your Moderator: Dick Flanagan W6OLD, [email protected]
> > > > > Icom FAQ: http://www.qsl.net/icom/
> > > >
> > > > ----
> > > > Your Moderator: Dick Flanagan W6OLD, [email protected]
> > > > Icom FAQ: http://www.qsl.net/icom/
> > > ----
> > > Your Moderator: Dick Flanagan W6OLD, [email protected]
> > > Icom FAQ: http://www.qsl.net/icom/
> > >
> >
> >
> > ----
> > Your Moderator: Dick Flanagan W6OLD, [email protected]
> > Icom FAQ: http://www.qsl.net/icom/
> >
> >
>
>
> ----
> Your Moderator: Dick Flanagan W6OLD, [email protected]
> Icom FAQ: http://www.qsl.net/icom/
>
> ----
> Your Moderator: Dick Flanagan W6OLD, [email protected]
> Icom FAQ: http://www.qsl.net/icom/
>