A local newbie bought a Vibroplex Vibrokeyer at a recent hamfest. He
brought it to me to help him get it adjusted.
After adjusting the spring tension (too tight no matter how 'loose'
the adjustments made it), and the contact spacing, I noticed that it
didn't key the keyer to which it was attached... and when it DID
(infrequently) cause the keyer to emit a tone, the electrical contact
of either level was not consistent.
Using an ohmmeter I confirmed that the GND lead of the connecting
cable was in deed electrically connected to the base of the keyer AND
the the yoke holding the dual levers. But NEITHER lever gave
continuity to ground...!
Removing the keying levers revealed that this was in fact, one of the
few paddles which came with synthetic ruby bearings which had not
long ago been crushed by excessive tightening of the adjusting
screws. However, given that the ruby bearings were still in place,
they provided for the levers to be well above ground potential to the
base, and thus to the keyer itself.
The ONLY method I was able to find that each keying lever might have
been 'electrically connected to the keyer base was via the
(contact-return 'tension' spring in each lever.
I've tried to find a contact method for Vibroplex but have had no
luck finding ANYTHING, unless I want to place an order for parts or service.
Does anyone happen to have a phone or e-mail address for
Vibroplex? And more importantly, can anyone confirm that the ONLY
source of grounding between the Vibrokeyer levers and the base of the
paddle is via the contact return springs? If so, man, that's a
HORRIBLY POOR connection to be relying upon.
Thanks for your time,
73,
Tom Hammond N0SS
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