I recommend the G5RV over a Windom. The length of a G5RV flat-top is
approximately 102 feet. The downlead on most G5RV antennas is 300 ohm
twinlead. The downlead length is 32-34 feet. The length combinations of the
G5RV flat-top and feeder provide impedances close to 50 ohms on 8 ham bands.
Some hams have used a DIRECT connection between 50-ohm coax and the twinlead
of the G5RV and have had good luck on some ham bands between 80 and 10 meters
without a tuner. I would prefer to skip the coax-to-twinlead transition and
use a good tuner with a balun.
If you run the tuner-balun setup, then the flat-top and feeder lengths are
not as critical.. as long as your tuner works on all 8-9 bands. If the
flat-top and feeder lengths are something different, then the antenna would
(technically) not be a G5RV but should work equally well.
The G5RV (300-to-coax version) works well with those "coax-only" tuners or
cheap tuners with limited inductance and capacitance inside. When tuner manuf
acturers cheat on L/C in the tuner, the tuner is less likely to work on
extreme impedances and antenna reactances. Some of those "companion"
coax-only tuners for brand "K" "I" or "Y" used to only cover 25-150 ohms...
and non reactive. Those values might not tune a Zepp with balun, but should
work with the tamer impedances-reactances on the feeders of a G5RV.
You would also want to feed a Windom with 300 ohm line and a tuner with
balun. Since the antenna is fed off-center, (unbalanced) there may be a
little more RF radiating from the feedline than in a G5RV, Zepp or
center-fed. The G5RV and Windom would perform about the same, with less
problems getting the G5RV to load on all bands.
There are some G5RV write-ups in ARRL and RSGB books.
72, Jay WB6AAM (ARCI 5050)
Search QRP-L Archives
QRP-L Archive |
[ 1993 | 1994 | 1995 | 1996 | 1997 | 1998 | 1999 | 2000 ]
This archive was generated by hypermail 2b29 on Fri Jun 02 2000 - 11:28:05 EDT