Returned from road trip late Thu night, started tinkering right after work
today (Friday). Replaced 75 foot of bad coax, replaced a switch in shack
with intermittent short. Still not getting anything close to what is
expected (some signal, ANY signal with a better S/N than what I hear on the
other antennas). In the hope of illuminating this sutuation, I am providing
the following details:
Bev antenna setup (apologies if this is a repeat) - 250 foot of 14 gauge
stranded 2 meters above moderate soil. Soil is carolina clay with moisture
from recent snows, among pines and oaks on a slightly sloped plane (sloping
down at 10 degrees away from the shack). Antenna is terminated with 470 ohm
resistor from DX Engineering. Transformer is DX Engineering as well.
The coax for the beverage is connected to the transformer at a height of 5
feet (someones suggested this is too high?). The ground connection (my DX
Engineering transformer has a connection for a ground rod) goes down to a 4
foot ground rod that is 3 feet into the ground (this is not coax ground).
At the far end of the beverage, the antenna wire slopes down to a height of
3 feet where it is tied off to a tree at the base and then connected to the
resistor. The resistor has a wire on the other end which attaches to the
ground rod at the far end.
Shack setup: Flex 3000, no beverage preamp, 300 foot of low loss coax.
Looking at the comparison antennas:
* Inverted L for 160, remote tuner at the base
* Half square for 80, remote tuner at the base
* 43 foot vertical for 40, remote tuner at the base
Other factors
* It does seem somewhat quiet here at my QTH. I do have 50 kV power
lines 750 feet from the shack, but they do not seem to have any noticeable
impact
* I live on an acre lot
I am aware of the following:
1. I should be looking for improved S/N, not strength
2. 250 foot is way too short for 160 but I should expect some
improvement over vertical antenna
3. One night of observation does not provide enough info for
conclusions about the antenna
4. It IS possible that I am in a very quiet location, and the beverage
is working as expected, and the other antennas are working extremely well
because of the low noise
5. Beverage antennas work best over soil with poor conductivity; mine
is average conductivity
Next steps:
1. Continue monitoring on 40, 80, and 160
2. Try adding some epsom salts around the ground rods
3. Investigate the possibility of using additional ground rods
4. Recheck connections
5. Use the MFJ 259 to conduct additional measurements at the feedpoint
of the beverage
Some questions:
1. I saw in some literature that the SWR should be fairly constant from
1.8 to 30 MHz, 2:1 or less. This measurement would indicate a properly
configured antenna. Is this accurate?
2. What measurements should I look for in the shack and/or at the feed
point to verify proper setup?
Mark Lunday, WD4ELG
Greensboro, NC FM06be
wd4elg@arrl.net
http://wd4elg.blogspot.com
http://wd4elg.net
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