Hi, Jerry, and everyone else,
I hope you don't mind me crossposting this to the Icom reflector. What
you've written (and I've tried to expand on) is a very good description
(and one far more detailed and technical than I could have given) of the
defects in the IC-211 and other Icoms of the same vintage. Considering
that there are folks on the Icom reflector considering these as good
used rigs to buy, I think it needs to be seen there. Besides, this is
now more on topic for Icom and off topic for Ten Tec.
>
> > The IC-211 wasn't a bad electrical design (other than the 100 ohm
> > resistor shunting the receiver input to drive the PIN diode and the
> > 150K resistor in the VCO control line leading it to be used as the
> > epitome of rotten phase noise at VHF, both cured by 1.8 uhy RF
> > chokes), but it had a bad double sided PC board design. They didn't
> > try to plate through holes but depended on flared nickel plated
> > eyelets, located many times under components. Worse yet the holes in
> > the pads were twice the diameter of the eyelets or the holes drilled
> > in the board, the eyelets were flared to a V, not flattened, and
> > Japanese solder won't stick to nickel. Soldering to nickel takes an
> > activated flux to work at all. So they encased each end of each
> > eyelet in a blob of solder (and did nothing different when the
> > broken radio was shipped back for service). In time those got so
> > open they wouldn't supply a femtoamp to a CMOS gate input.
This problem was common to the IC-701, IC-720, IC-720A, IC-245, and I
believe the IC-280 as well. All Icom rigs of that particular and
thankfully shortlived vintage are best avoided. Besides, each of the
rigs in question had other serious problems. The CMOS IC chip used in
the IC-211 and IC-245 is absolutely irreplaceable today other than from
another rig. The bandswitch solenoid in the IC-701 and IC-720/A is
equally impossible, though a suitable replacement can be found. The
replacement, though, requires major surgery to the rig to install. No
fun in any case.
> > I've fixed all I can reach and used #20 solid buss bar to
> > parallel some essential circuits under the board, and sometimes can
> > make contacts with my IC-211 (I sold it once but it came back, I
> > won't try it again).
I did that repair myself, with some coaching, on an IC-245 with the SSB
adapter. We are talking about 2-3 hours of soldering. It's an
experience I will not repeat. Without someone experienced over my
shoulder watching my work I would have given up quickly.
> > The only other complaint I had was that the LEDs in the display
> > weren't bright enough to see in the mobile in the daytime.
Again, that was true of all Icoms of that vintage. Basically, and Icom
with a red LED is not good in a mobile enviroment, even later ones like
the IC-290A. The VCO in the IC-290A was microphonic as well, making for
lovely feedback if you turned up the volume to hear in a noisy mobile
environment. Considering that the IC-290A was a mobile rig, this made
for a really poor design.
> > I might attack that synthesizer control board
> > again, or replace it with a VXO or a new synthesizer control design.
> > Today it would be easy with one of the dedicated control chips and a
> > PIC chip for the dial interface. If there are still any IC-211 that
> > haven't been landfilled, there might even be a market for such a
> > product.
Take a good look at eHam, eBay, or a large hamfest. There are a lot of
IC-211s still in service. I still hear them on 2m SSB now and again.
Many have had the repairs made, but many have not. It's impossible to
tell which are which and if an owner of one of these is less than honest
you can end up with a doorstop, or at least a tedious repair job. The
performace of the IC-211 really isn't that awful if everything works.
That's a huge "if". Methinks saving a few more pennies and buying newer
technology makes a whole lot of sense. That, or else buy older
technology. The ancient, analog IC-201 and IC-202/S were reliable and
had very nice receivers indeed.
73,
Caity
KU4QD
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