Dave wrote:
Gemtlemen:

I like to listen at night to the group on 3.805,
but, now after listening for an hour or so the my receive goes dead,
below 8.000MHz.

I shut the radio off and after it cools down,
the receive returns.

I bought the radio new in 1986. It has every filter,
remote, even the "High Stability Crystal"

Never had a problem until now.

What could be the problem ?

Thanks in advance,

73 de Dave - N2JBO "Just Being Obnoxious"


There are a number of problems with R-71A that develop as it ages.
Many of them heat related. Solder joints begin to crack around the
voltage regulator in the power supply. Oxidation causes chassis ground
connections to open....there is quite a list.

Very likely, something has simply aged to the point it falls out of
tolerance as internal temps rise, or a mechanical connection opens due
to expansion of an oxidizing metal contact.

I had similar problems with mine.

Two recommendations. Open it up, and touch up the solder joint around
the regulator. That's an enormous source of trouble on aging ICOM rigs
of this vintage. ICOM does it as a matter of course on all incoming ICOM
rigs in Bellevue. Then check all points where a mechanical connection is
made from a circuit board to the metal chassis. Remove screws, clean any
oxidation you may find there. It might be smart to put a star washer
under the screw when you replace it. Verify that all internal
connections are tight. Some are made using springs. A little oxidation
here, and you'll be in a strait jacket before the weekend.

For specific troubleshooting, ICOM maintains a database of
problems/solutions in the form of an FAQ for older receivers. Give that
a look at ICOM.com.

The second recommendation is to consider going the full distance and
sending it back to Bellevue for a makeover. ICOM service is very good.
VERY good. If you get them on a good day, a phone call may get you a
quick solution you can implement fairly easily. You're a ham, you've
certainly got the technical know how. Then again, Bellevue has both the
technical knowledge AND the knowledge of the indiosyncracies of this
rig, ready access to parts, and tooling and hardware to not only
diagnose problems, but to return the rig to factory specifications.
Those trimmers on the PLL board, for instance, become sources of
problems for low level SSB listening, and eventually need to be
replaced. If you still have the original memory board, they can replace
the battery for you and reflash the memory as needed. You know, little
crap.

Bellevue's service is relatively quick, very good, and because they
know what they're doing a lot less expensive than someone who isn't
factory trained. I sent my R-7000 in for a makeover and it came back as
new, for less than $200 including express shipping both ways.

Give it some thought.

ICOM's Knowledge base is he


http://icomamerica.com/support/kb/