Dr. Gerald N. Johnson, electrical engineer wrote:
>
> 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. 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). It has the nicest S/N on receiving SSB of any of my VHF rigs.
> Says something for single conversion like the classic Tentecs like the
> Triton.
>
> 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. LEDs with more light
> are now available cheaply. 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.
>
> 73, Jerry, K0CQ
> --
> Entire content copyright Dr. Gerald N. Johnson. Reproduction by
> permission only.
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