As a follow up to my emails about the troubles with 2 of my Beverage
antennas: I found that one of them had an old connection between the
beverage box and the antenna that had been covered with liquid tape and had
deteriorated under the tape. Making a good connection to the antenna solved
that one.
The second was not so easy. Resistance measurements were normal and I
traded out the transformer with a used one to no avail. (I decided not to
take a working transformer out of a working Beverage so close to the
contest.) I dragged the box and coax into the shack. I put a 75 ohm
resister across the coax and had good SWR transmitting 1 watt into the feed
line. OK, the coax is good. Then I put a 470 ohm resister across the
output of the Beverage transformer (after reinserting it) and the SWR was
bad. I then decided the core had become degraded somehow and it (and the
other one I tried) were bad. I don't know how or why, but they were. Dave,
K1TTT warned me about this so I put out an emergency message to find a new
transformer or a core to wind one to no avail. It was the day before the CQ
160 contest, so I did not have any time to spare. I looked through my huge
amount of stuff collected in my 53 years (and I am not even that old!) of
ham radio and found an Amidon 150 core. I discovered it was close to the
right permeability and ran to the "Shack" to get some #20 and #22 hookup
wire. I was astounded that the young lady who greeted me actually knew what
it was and how to find it, so I was off in a hurry. I had some glass cloth
tape and I wound my first "UNUN" according to Jerry Sevick's formula and now
have a 100 watt transformer with low SWR in my NW Beverage! I felt great
that my first try at winding an UNUN worked and also that all 4 of my
(albeit short) Beverages was working. (Now I am thinking about putting the
2000 watt rhombic terminating load I collected from who-knows-where on the
end of a Beverage and transmitting into it... Hummmm)
Anyway, I got everything working before the contest, but I have some noise
source that kept the meter over S-9 all the time on the vertical transmit
antenna. Since I am on a small piece of property, it was transferred to the
beverages. The northeast beverage was the least affected luckily, so I
heard about 25 strong Europeans. I was surprised the Europeans were so easy
to copy and the stateside guys were, many times, much weaker. I never was
able to copy any station on the vertical all weekend. The SE Beverage was
the noisest by far. I think I transferred the noise from the power line
close to the end of the SE Beverage to the vertical where the Beverage
passes close to the end of one of the elevated radials. Then the vertical
reradiated the noise.
It kind of reminded me of the first year I made a huge ground plane for 160
by converting the 160 inverted V to radials and flying a plastic helium
balloon shaped like a wing to hold up the vertical portion of the antenna.
I attached the balloon about 3 feet above the top of the vertical and the
static charging was huge and made a terrible noise on receive. What an
alligator I was! The next year, I put about 20 feet of nylon line
separation between the antenna and the balloon and it worked ok. (But not
as good as one would think.)
The weekend before during ARRL CW, I worked 29 Europeans on the vertical. I
noticed the noise then, but it went away before the contest.
By the way, I found that power tool battery chargers left plugged in with no
battery inserted can be a significant source of noise that sounds like an
electric fence charger.
Thanks everyone for the suggestions and the contacts on 160. I think I will
go single band 10 meters next weekend. Hi
Chuck W5PR
----- Original Message -----
From: "K1TTT" <K1TTT@ARRL.NET>
To: "'Tower and HF antenna construction topics.'" <towertalk@contesting.com>
Sent: Thursday, February 25, 2010 6:16 AM
Subject: Re: [TowerTalk] Beverage Antenna Problem
> It can definitely be the transformer. Just had one go bad here either
> from
> lightning or moisture that corroded the connection, can't tell for sure.
> Compare resistance readings to the working one or trade them and see if
> the
> problem moves.
>
>
> David Robbins K1TTT
> e-mail: mailto:k1ttt@arrl.net
> web: http://www.k1ttt.net
> AR-Cluster node: 145.69MHz or telnet://dxc.k1ttt.net
>
>
>> -----Original Message-----
>> From: Chuck [mailto:w5pr@swbell.net]
>> Sent: Thursday, February 25, 2010 03:02
>> To: tdxs-list@tdxs.net; Tower and HF antenna construction topics.
>> Subject: [TowerTalk] Beverage Antenna Problem
>>
>> I have been trying to repair my 4 beverage antennas. Wires and
>> terminations are good. 2 of the beverages work well, 2 are "dead" I
>> have
>> checked the coax and connectors are ok. Other than broken wires, what
>> can
>> go wrong with the transformer? What the heck am I missing? Short to the
>> core? I will try moving a transformer from a working Beverage to a dead
>> one to see if that is the problem. Both "dead" ones have RG-59 coax with
>> foil and shield to them. The working ones have other types of coax. All
>> have transformers from ON4UN that used to work great. 3 are 600' one is
>> 800' the 800' and one 600' are not working.
>>
>> I guess I should try the substitution of another transformer first...
>>
>> Thanks
>>
>> Chuck W5PR
>> _______________________________________________
>>
>>
>>
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>
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