In a message dated 1/30/2007 3:25:51 P.M. US Mountain Standard Time,
towertalk-request@contesting.com writes:
> I use an inverted V for 75/80 meters. It hangs from my tower from about
80
feet and has worked fine using a tuner for the past 6 months. Last night
the VSWR went out of sight. After a while trying different tuner settings,
it was brought back to flat. However, as I began to transmit (SSB) the VSWR
went wild again and I had to settle on listening to the guys on the net.
> What problem should I be looking for? The antenna is an Alpha-Delta
DX-80.
I have had it for about 5 years in various operations, including the past
two Field Day operations. It is fed with about 90 feet of LMR-400 plus 50
feet of RG213 connected with a barrel connector. We have had a lot of
rainy, cold weather over the past two months and I am wondering if the
problem may be caused by resistivity in the wire connections at the center
insulator.
High SWR everywhere is typically a feedline problem, including the
balun. If this is a trapped antenna, that's another potential problem.
Start with the antenna and work backwards. Put an antenna analyzer at
the antenna feedpoint and see what's what. If the antenna's okay, keep going
down to the shack.
Cheers,
Steve K7LXC
TOWER TECH -
Professional tower services for hams
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|