schematic for HD 1481

[Multi-Volti]

I don't remember if Heath had one model with multiple relays or not, but
someone does. The Heath one I was familiar with used a Ledex rotary solenoid
(which are pretty expensive nowadays) which had a switch section also. The
shaft also rotated an external ceramic switch wafer with matching indexing
(angle of position).

The integral switch wafer (non-ceramic) was wired so that the Ledex solenoid
would rotate repeatedly until it reached the position that 'matched' the
desired one. There might have been a contact that momentarily interrupted
with each actuation, causing the repeated pulsation. I am not very
mechanically inclined, and attempting to figure it out was too tedious for
me. It reminded me of a resolver position indicator arrangement in that it
was unstable until it reached the position that opened the wiring to the
ratchet device. I keep adding details as I remember them...sorry. I think it
only went in one direction, so that if you reversed one position, the
solenoid had to actuate repeatedly to cycle thru all the positions to get to
the one you wanted.

Maybe someone else can confirm this - I didn't dream this up, really! It was
pretty cool to watch with the cover off, but noisy mechanically as well as
electrically. I recall it making a pretty bad racket resonating bolted to a
tower.

Murray


----- Original Message -----
From: Kenneth Laine Ketner <ketner at ARISBEASSOCIATES.COM>
To: <HEATH at LISTSERV.TEMPE.GOV>
Sent: Thursday, July 17, 2003 8:18 PM
Subject: schematic for HD 1481


Greetings greenies:

I am doing some antenna experimenting, and need a function like the
Heathkit HD 1481 remote coax switch. Does anyone know of a schematic for
it on the web. Didn't find one on BAMA.

Lacking a schematic, maybe someone can describe the mode of operation. I
understand it switches a remote box on the tower by sending  12 VDC
pulses along the coax (no extra wires needed for switching). One coax
cable up the tower, and 4 antennas switchable at the tower top box. This
is the kind of function I need. Just what are the details of how it does
that?

--

Ken Ketner
ARS KA5ELD (Extra Class)
  Personal Webpage: http://www.wyttynys.net
  Office Webpage: http://www.pragmaticism.net
Email:
 home: ketner at arisbeassociates.com
 office: kenneth.ketner at ttu.edu

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Lubbock, TX 79464

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