Hi Ash, Hello All, As a long time Beverage user, I can definitely say that the performance can be enhanced by having good ground at the termination resistor end of a beverage.
Operating from Aruba in a CQ160CW contest, W8UVZ, KD9SV and I put out a proper 470 ohm non inductive resistor on the end of a 560 foot long beverage, and in addition to the ground rod, fanned out about 8 radials each about 17 feet (5 meters) long beyond the end of the beverage antenna wire. I will also state that putting a Hi-Pass filter in series with the coaxial cable at the receiving end in the radio room was a big help. I lived 1/2 mile from an AM 930 station that made it impossible to make measurements with an SWR bridge in a receiving mode. The only way I could evaluate my RX antennas was to transmit 2 - 3 watts into the beverage and use a low power SWR bridge to look at the forward & reflected power, which worked very well for me. My typical SWR on 160 meters was 1.5:1 from 1800 to 1915, and I considered that good enough. I did not worry about the SWR on 80 or 75 meters, but found good receiving advantages compared to my transmitting antenna most of the time. 73, Good luck, George, K8GG > At 14:33 2018-07-06, Ashraf Chaabane wrote: >>Hi Mark, Peter, >> >>The BC station to be used to minimize the back lobe would be in >>Egypt or Saoudi Arabia right on the back of my beverage antenna. >>That should offer signals coming well above 10deg (I presume!). >>Comment noted regarding how efficient that will be on 1820 kHz. I >>know Egypt has BC station on Medium Wave which isn't that far from 160m. >> >>Frank, >> >>I have two 3-feets rods at each end so far with two buried radials >>at the feed end. I will add radials at the termination side as well >>as you recommend. >> >>For the sake of experimentation, I will play a bit with the >>termination resistor trying to flatten the SWR curve as much as >>possible, although, as many said, I shouldn't expect a noticeable >>improvement in reception. >> >>Thank you all and those who wrote me in private. This generous >>technical support is needed for developing experience on 160 among >>3V hams (mostly youngsters). I hope we will be ready with strong >>100W signals this winter! >> >>73 from Tunisia >> >>Ash 3V8SS/KF5EYY >>www.kf5eyy.info >> >> >> >>------ Original Message ------ >>From: [email protected] >>To: [email protected] >>Cc: "Ashraf Chaabane" <[email protected]> >>Sent: 04/07/2018 19:00:33 >>Subject: Re: Topband: Beverage Antenna Tuning >> >>>Hello Ash, >>> >>>Your results are normal for a typical Beverage. Receiving performance >>>is not significantly degraded by imperfect matching of the coaxial >>> feedline >>>to the Beverage feed point or by non-optimum termination resistance. >>>You could optimize your matching transformer and termination resistor >>>but the improvement in receiving performance will be very minor. >>> >>>On the other hand, Beverage antenna receiving performance can be >>>significantly degraded by: >>> - nearby antennas, power lines and other long conductors, and >>> - common mode signals coupled into the feedline >>> >>>You could optimize your matching transformer to reduce the VSWR to >>>closer to 1:1 on the frequencies you care about most, but you won't >>>notice any improvement in receiving performance. >>> >>>You could optimize your Beverage termination by: >>> - adding extra ground rods and/or short radials to improve >>> ground resistance >>> stability at the connection to termination resistor. >>> - adjusting the termination resistance to minimize the VSWR >>> excursion >>> as you sweep from 1.5 to about 10 MHz >>> >>>73 >>>Frank >>>W3LPL >>> >>>-------------------------------------------------------------------------------- >>>From: "Ashraf Chaabane" <[email protected]> >>>To: [email protected] >>>Sent: Wednesday, July 4, 2018 2:13:27 PM >>>Subject: Topband: Beverage Antenna Tuning >>> >>>Hi All >>> >>>I measured the SWR in my beverage antenna; the SWR fluctuates between >>> 1.5 >>>and 3 in a range of 1.8 to 7 MHz. (See: >>>https://drive.google.com/drive/folders/0B9AtNpPfAOUMRDNsaXROMG1VUTg?usp=sharing >>>) >>>I know SWR should not vary too much. However, some people are suggesting >>>adjusting the termination resistor. Others suggest checking the >>> transformer >>>number of windings for a good match. What shall I do? >>> >>>73 Ash 3V8SS/KF5EYY >>>_________________ >>>Topband Reflector Archives - http://www.contesting.com/_topband >>_________________ >>Topband Reflector Archives - http://www.contesting.com/_topband > > Nick Hall-Patch > Victoria, BC > Canada > > _________________ > Topband Reflector Archives - http://www.contesting.com/_topband > _________________ Topband Reflector Archives - http://www.contesting.com/_topband
