[Top] [All Lists]

[TowerTalk] Switching 450 ohm twinlead?

To: <>
Subject: [TowerTalk] Switching 450 ohm twinlead?
From: (Jim Reid)
Date: Fri, 06 Jun 1997 16:20:33 -1000
At 09:27 PM 6/6/97 -0400, L. B. Cebik wrote:

>Unless you are using a matched 450-ohm load to 450-ohm lead, the impedance
>bumps created by relay spacing will be in almost all instances meaningless
>and minor, with no consequences for efficiency/loss of the power transfer.
>Also, be sure that the relays can handle the high humidity that will
>inevitably be present in the remote box.  Corrosion does not require
>direct contact with rain drops.  

Loyd Colvin,  in his 8/56 QST article,  suggests leaving a small
voltage on the relay coils.  This to provide a bit of heat to
drive the moisutre away.  Wonder if it really works,  I will try
with my set up.  Plan to use a Radio Shack enclosure for the
relays/450 ohm lead/V-beam wire connection.  Guess will use a
metal box rather than the plasic ones.  Must find some feed-thrus
to mount/terminate wires.

73,  Jim, KH7M

FAQ on WWW:     
Administrative requests:

<Prev in Thread] Current Thread [Next in Thread>