[VHFcontesting] Fw: Antennas & digital modes

[Herb Krumich]

PM
Subject: Antennas & digital modes



I want to bring  attention to others what can happen with your DE with high power
About five years ago, I downsized to a single 17B2 Cushcraft from four on 144 mhz.  The stack was very hard to repair every year after ice storms here in the Pocono's.
With the single antenna, I was doing some JT one evening on my moonset.  My amp will run a full 1,500 watts on CW but when doing digital modes, I always drop the power to 1,000. I am not sure how long it took, but that evening I melted the balun on the DE. Basically set it on fire. When I looked inside the Cushcraft box, I could see how this happened. The balun of coax was very thin. Just looking at this stuff, I knew there was no way it could take, especially on two meters.
I probably had 750 watts at the driven element at the time..
This week I was running FSK with Bill ND0B in N.D. on 222 mhz.  Bill decoded my signal almost immediately. Good sign. BTW I was again running 1,000 watts and about 750 at the antenna
We continued for about fifteen minutes until I saw my power had dropped. I switched my watt meter to return and the meter was pegged.  
With winter here, I have no idea exactly what happened but there can only be two things. The DE on the M2 antenna, or my jumper cable from the 1 5/8 hardline.
It will be several months before I can find the problem.  But I'm betting the balun went bad.
Right now I can't complain about M2 but I do know that Cushcraft surely should change their power numbers for the 17B2.  In calling the company, they told me it was PEP power. That's not what is marked on their advertisement.
That's the complaint of the year from the snowy Pocono's
73's and HNY
Herb at WA2FGK