[1000mp] sticking relay problem and W8JI mod.

[W0UN -- John Brosnahan]

As I have mentioned, my 1000MP would lose about 60 dB (or more) of
sensitivity after an hour or so.  So I assumed it must be temp related.
Yet I could hit the MOX button and it would come back to life, although
only for a few seconds typically.

Well, I thought, maybe since I have only used it for RX for the past
couple of years and hitting the MOX button will get it back sometimes,
as well as turning it off for an hour, maybe it just needs to be cycled
into transmit.  So I hooked up my keyer, turned the RF all the way
down and ran a few hundred dots at 25 WPM.  Now it is dead all
of the time.  I can faintly hear ONE, 50KW AM station very weakly.
(WOAI is not all that strong in the best of times at 85 miles away
and we are on a plateau, shielded from them.  But at S9 the station
is the loudest signal on the AM band.

So now I don't know if freeze spray will work or not to help identify the
culprit.  But since it continues to seem like a relay (or relay driver)
I can inject noise into various points as a quick way to isolate the
problem.  (He said, over optimistically.)

And now for the good news, the service manuals have apparently
been out of stock for a few months, but Vertex received FIVE from
Japan a week or so ago and mine arrived yesterday.  So I will have
some idea where I am poking or injecting.

73--Mr. One Percent



At 01:45 AM 3/24/2004, you wrote:


>Tod:
>
>
>  Instead, it would seem that the
>transistors controlling the relays also fail (somewhat).
>
> >>Transistors rarely fail "somewhat"--failures tend to be catastrophic.
>
>
>  I suspect that if we were to poll
>everyone on the reflector we would find that the 'sticky relay problem' may
>be something experienced by 1% or less of the readers.
>
>
> >>While one expects to hear more from those with a problem than from those
>without, the frequency of reportage of the "sticking relay" problem suggests
>quite a bit higher incidence than 1%.
>
>Garry, NI6T
>
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