Hi Joe,
Thanks for the additional info on the G5RV. It's nice to converse with you
on the subject. As a matter of fact, I've never tried a G5RV after seeing
one while pulling it up at a friend's house in the early nineties. At that
time, I noted it's feed line arrangement and decided it wasn't for
me. I've actually stuck with the ladder line feed all the way into each
ham shack at 3 different homes now for these center fed, 100+ feet sky-hooks.
I suppose trying this feed arrangement would be in order. Based on what
you've said, I would either live with the coaxial losses, or use a lower
loss coax (RG 213 or better that's able to handle a mismatch) for that
short run into the shack and tune it there. How does this arrangement
handle high power? I suspect the RG 303 in the balun will do this quite
easily on HF, but what of the core? You've renewed my interest, but I'm
still such a fan of the complete ladder line feed arrangement. 73 de
Steve, KZ9G
At 07:24 AM 7/6/2002 -0400, you wrote:
>Steve,
>
>With the G5RV dipole, you get reasonable VSWR on the major bands. On 80
>meters it may get to 3:1 or so at edge of band but all my rigs with built
>in tuners worked fine and never used an external tuner.
>
>There is a myth out there, perhaps started by G5RV himself (!), that
>80-100 feet of coax is needed. If you think about that a minute, you'll
>see that the only purpose of the long piece of coax is to lower the VSWR
>(due to it's inherent loss).
>
>The easiest way to feed a G5RV antenna is to use a 1:1 current balun at
>the end of the 450 OHm feed line (about 30-35 feet from the center of the
>dipole). I use a W1JR type current balun, about 12-14 turns of RG142 or
>RG303 PTFE 50 Ohm coax wound on a 2.4" diameter toroid. I also have used
>about 50 ferrite beads like the W2DU balun. They al;l work great and many
>are available commercially.
>
>My son Jim, AD1C, has a similar G5RV only up 30-35 feet and has worked
>over 325 DXCC in the last 4 or 5 years! The G5RV is a compromise antenna
>that does work and is not a DUMMY LOAD!
>
>73,
>
>Joe, W1JR
>
>At 01:08 AM 7/6/2002 -0700, Steve G. wrote:
>>Yep... it's hard to beat these simplistic center-fed antennas that Tom
>>has described. Just match or "tune" these low loss antenna systems
>>(system = antenna and balanced feed line) with a capable tuner, and work
>>the world. A combination of low and high ones like the 100' or 135'
>>models would serve stateside and DX interests. Just take into
>>consideration their patterns when changing bands. BTW, many articles
>>have been written on these balanced line, center fed antennas. They show
>>the patterns, takeoff angles, and the varying amounts of gain they have
>>for each band, considering different heights above ground. I'm sure
>>someone can point out the specific articles - I remember one in QST a few
>>years back. Who needs a G5RV with it's coaxial losses if you can bring
>>"ladder" or open wire line into your shack? With a complete balanced
>>line run from the tuner to the antenna, these are SUPERIOR and
>>ELEGANT. I've enjoyed them at different locations over the years...
>>though I sure wish they were at 100+ feet like Tom's!
>>
>>73, Steve, KZ9G
>>
>>At 01:20 AM 7/6/2002 -0600, you wrote:
>>>A *simple* solution to the 100 ft space limited antenna problem
>>>is to just install a 100 ft center fed dipole using Ladder Line feeders
>>>and an Antenna Tuner such as a Johnson Matchbox.
>>>
>>>I have 4 Ladderline fed antennas (2 - 80M dipoles, 1 - 100 ft CF,
>>>1 - 20M dipole) which I use extensively on 80M the WARC bands.
>>>I have worked over 320 countries on each of those 4 bands.
>>>(OK, the 80M dipoles are at 130 ft and the 100 ft CF is at 100 ft)
>>>
>>>Tom N4KG
>>>
>>>On Sat, 06 Jul 2002 "S. Markowski Jr." <km9m-zig@attbi.com> writes:
>>> >
>>> >
>>> > Van K7VS wrote:
>>> >
>>> > > with a g5rv, keep your antenna tuner handy as you WILL need it
>>> > for all
>>> > > bands. Certainly a compromise antenna but useful in some
>>> > instances.
>>> >
>>> > You "CAN" work alot of DX with a G5RV and 100 watts. You will learn
>>> > one new character trait.....
>>> > "PATIENCE"!
>>> > 73,
>>> > Zig KM9M
>>> >
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