Ford,
You are "missing" BALUNs at each antenna.
Think about it. The beads you installed acted like/as a BALUN and isolated
your 40M dipole from the switch and everything else.
That's the reason why one would/should use a BALUN.
Bill, N3RR
----- Original Message -----
From: "Ford Peterson" <ford@cmgate.com>
To: <Towertalk@contesting.com>
Sent: Thursday, May 30, 2002 11:48 PM
Subject: [Towertalk] Remote Switches
> Until recently, I was using a remote switch on my tower (it fell a couple
of
> weeks ago). In looking at a design to replace it, I want to incorporate a
> remote switch. Several manufacturers seem to make what appear to be
widely
> accepted devices. They all have one serious flaw as far as I'm concerned.
> 1/2 of all the antennas are DC connected at the switch chassis
permanently.
>
> On my old system, the box was mounted at 67' or so. A short feedline went
> to each of several antennas. In each case, the braid was connected to one
> of the elements of the antenna. When you hook them to the switch, they
are
> all connected together through the chassis of the switch.
>
> On my 40 meter dipole, the RF in the shack was horrible. Think about it.
A
> 40 meter dipole mounted about 1/2 wavelength in the air. One side (the
> braid side) is connected to a switch whose chassis is bolted to the
> tower--the chassis is 1/2 wavelength from a series of ground rods, 160
meter
> radials, etc. Does that make the 68' point a low impedance on 40 meters?
> Am I the only one having trouble with remote switches or is it the way I
use
> them?
>
> The fix in this case was about 20 type 43 beads on the feedline between
the
> switch and the 40 meter dipole. As far as I'm concerned, this was a
patch.
> That antenna never played well. The rest of the antennas (yagi, 3
dipoles,
> etc.) all had one side connected together through the switch. God only
> knows what the pattern really looked like. Sure I could get a good load
on
> just about any band but God only knows what was really radiating...
>
> What am I missing here? To switch, or not to switch, that is the
> question...
>
> Ford-N0FP
> ford@cmgate.com
>
>
>
>
> _______________________________________________
> Towertalk mailing list
> Towertalk@contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
>
|