[1000mp] MP RX TR relay repaired

[Pete Smith]

At 01:20 PM 4/13/04, W0UN -- John Brosnahan wrote:
>At least in MY case the failure was the obvious, electro-mechanical
>component and there was nothing particularly esoteric about the
>fault.


It's interesting that some relays seem really prone to this sort of 
problem, while others are not.  I recently rebuilt my 80m array relay box, 
using nice small sealed PC board relays instead of the big honkin Radio 
shack plug-ins used before.  since then I've found that every few days when 
I first turn the array to a given direction I need to "blip" the relay with 
a little RF before receiving sensitivity is normal.  This never happened 
with the old, big relays.

I think I recall someone (w8ji, maybe), talking about relay designs that 
avoid this problem by wiping the contacts against each other to rub off the 
molecules-thick oxide layers that form, or else using contact material that 
doesn't oxidize so readily.  Maybe it's just a contact material issue (and 
another black eye for Yaesu's engineers).

Since this is RX-only, I wonder if a modification to feed a little DC 
across the NC contacts wouldn't be the sure solution.


73, Pete N4ZR
The World HF Contest Station Database
is back, at www.pvrc.org/WCSD/WCSDsearch.htm