Hi Gene,
On 80m, instead of changing the length, I increased the effective diameter by
using a cage design. The free design program on smeter.net
(http://www.smeter.net/antennas/wire-cage-dipole.php) says it looks like a 7.7"
diameter conductor. My 2:1 VSWR bandwidth is supposed to be 318 kHz but, I'm
seeing over 500 kHz. A sloper would work about the same.
Since the apex of my inverted vee is at 70' and I have about 85' of coax
feeding it, I thought it worth trying to feed it as a vertical against a radial
field on 160m. The ATU in my TS-850SAT is able to tune into it. I use a
Jennings RJ1-series SPDT vacuum relay in a plastic box to do the switching. I
use a "bias tee" to feed 13.8V from the shack power supply via the coax to the
relay's 12VDC coil.
Related images and more info on my Flickr page:
http://www.tinyurl.com/wa7prc-80m-160m
vy 73,
Bryan WA7PRC
________________________________
Date: Thu, 23 Nov 2017 12:17:33 -0500
From: "Gene Smar" <ersmar@verizon.net>
To: <towertalk@contesting.com>
Subject: [TowerTalk] Relay for sloper element
TT:
I want to be able to switch a piece of #14 house wire onto the far end
of a sloper wire I have for 75 M phone so I can operate lower in the band.
I'm thinking of adding a relay in a weather-resistant box at the sloper's
end insulator and continue with the extension wire beyond that.
FYI: The sloper wire runs from the 50 foot point on my tower to my
house roof where it is tied to an end insulator and thence to a PVC vent
pipe via a bungee cord. The wire runs through tree limbs, hence my need for
a flexible connection. I'm thinking I can mount the relay/box near the end
insulator and extend the additional wire further across the roof. I'm
thinking I can run 15 +/- VDC to it from the station supply in the shack via
RG-58 coax up and across the roof to the relay box.
My question to this august group: What relay (and supplier) would you
recommend for the job?
In the alternative, can you point me to a good source of info on
designing traps for said application? The trap would not require any DC for
switching but might take more "cypherin' " to get working.
Many thanks and Happy Thanksgiving to all y'all.
73 de
Gene Smar AD3F
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