[Icom] More on isolation relay with non-ICOM amps

[W3UIO]

Hi Adam. TNX for the clarification. I certainly defer
to the expertise of you and others who have posted
here. All such posts appreciated, to be sure.


--- Adam Farson <farson@shaw.ca> wrote:
> Hi Larry,
<snip>
> << What about the typical contester sending at 35 -
> 40
> wpm with a relay rated for 10 wpm, or am I missing
> something? >>
> 
> I think you may have missed the thrust of my
> previous posting. The relay
> manufacturer did not rate the relay for 10 wpm. As I
> mentioned, our
> component engineers tested reed relays at 1200
> ops/min (equivalent to 40
> wpm, or 4 times the OMR-109F spec), without
> observable degradation. The
> contact load for these tests was 50 ~ 100mA at 50V -
> far higher than the 5mA
> at 12V which I suggested to maximise contact life.
I don't doubt the longevity of the relays as long as
they operate under proper ratings. I was just under
the impression that the relays were failing because
the SPEED of operation rather than the NUMBER of
operations had exceeded the specs.


<snip> 
> However, I would remark that I
> have been using solid-state amplifiers - first an
> IC-2KL, now a Yaesu
> Quadra - for a total of 14 years, without a buffer
> circuit. The reed relay
> has never failed in any of my exciters.
> 
> Both amplifiers present a TTL-level keying load (5V
> at a few mA) to the
> exciter. If the amplifier presents a 12V/7mA load,
> as do the current Alphas,
> a buffer should not be necessary.
Right, but my Alpha 76CA is 20 years old; however, I
have used the SB-200, the Henry 2KD5 and the Alpha
with various Ten-Tec, Kenwood, and ICOM rigs with no
buffer and no problems resulted. This appears to be a
recent phenomenon.

A local ham fused the contacts in his ICOM the first
time he tried it with a non-ICOM amp. The amp would
not unkey.


 As Larry W0QE
> stated, "as long as you
> don't weld the contacts by exceeding their rating,
> [small reed relays] are
> often good
> for a billion operations."

=====
Larry, W3UIO

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