Topband: Twisted Pair Telephone wire for Bi-Beverage
Walter Schulz
k3oqf at localnet.com
Tue Jul 27 18:35:25 EDT 2004
Dear Gentleman,
Twisted pair use for Beverage Antenna requiring a balance open wire line is not exactly a great idea. In telephone work the tip and ring conductors are twisted to prevent crosstalk. Also you should be aware that the maximum bandwidth in this configuration is about 19 KC unloaded. Therefore, because of the shunt capacitance on high frequencies the radio frequencies would be attenuated greatly.
My suggestion is to un-twist the wire pair making two single wires. It will work alot better in that configuration. I would also suggest using a single wire Beverage with the appropiate matching transformer at each end of the antenna. Feeding each antenna end with coaxial cable, connecting one end to the radio receiver while terminating the other end with the appropiate resistance. Wishing to change reception direction simply reverse the connections.
Two wire Beverages work, but there are alway problems with the matching transformers windings being balanced. If you do not have lab equipment to check on balance and few other things the results are not that good.
I worked for the telephone company here in states, television transmission via microwave and office information systems during my last 9 years with the BTC. I had a total of 30years before retiring. then I went back out to sea as radio officer VQ9 land. I been doing this stuff for awhile.
W8JI's Tom's web site has alot of good information about Beverages, if you follow his suggestions you cannot go wrong. Also, trying looking at W3LPL and the Yankee Clipper Club's website. I would strongly suggest since you are in Europe, contacting Peter DL2NBU or Uli DL2YA I think you will find their views on Beverages very interesting.
Hope this will help you, Good Luck.
Rgds,
Walter sends.....
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