ANTENTOP- 01- 2016 # 020

Modified Beverage Antenna

By: Igor Grigorov, va3znw, Richmond Hill, ON, Canada

I took the decision. At last! I took the decision to participate in CQ- WW- 160- Meter Contest. My setup for the Contest was IC- 718 and Beverage Antenna described at Antentop- 01, 2015 (http://www.antentop.org/019/va3znw_019.htm). The antenna had termination resistor 450- Ohm/25- Wtt. It allowed me run the IC-718 on 50- Wtt without damage to Beverage's termination load. So I decided participate as Low Power (up to 150- Wtt) Single Operator in the Contest.

Finally Friday -29 (2016) came in. Of course, when I came home from my job I did not run to the transceiver like a crazy rabbit. I would like do contesting for my pleasure not for big result.

However my transceiver was turned on. CQ TEST from USA stations blown up my headphones. I worked several hours in the test and discovered that the 50- Watts is too little to be heard. Then I took another decision. I increased output power up to 100- watts (96- Wtt actually). It gave result. Contest stations begun to answer me in much better way (or it was seems to me..).

I was known that termination load at Beverage Antenna could not stand 100- watts for a long time. However I kept hope that frost (it was minus 7 C degree) and wind (feels like minus 15 C with wind) cool down the load. For some times the cold weather hold situation under control. But... Suddenly SWR became floating. At every key down antenna current became floating too. Finally at the end of a short contest QSO the SWR- meter of the IC- 718 showed infinity. It was happened what I waiting for. Termination Load at the end of my Beverage antenna was burned out.

 I took a break in my contesting. I expected the situation so I acted on to my plan. It was interesting for me how the Beverage antenna with burned load (anyway, it is already not a Beverage antenna it is low profile wire antenna) would be worked at the other bands. I made measurement of the antenna with help of SWR- Meter of the IC- 718 and with help of MFJ- 259B. Table 1 shows SWR of the Beverage antenna with burned load measured by IC- 718. 

Note: I use to a Japan made wall mounted SWR- Meter (Handic brand) constantly turned on to the antenna cable. As usual I use to the SWR meter to measure antenna current while transmitting. However seldom I use the SWR- Meter to measure SWR in my antenna (to prove the IC- 718 internal SWR- Meter). Sometimes I used FSM function at the SWR- Meter.

Japan made SWR- Meter - HANDIC

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