Dave
not true
sure the G5RV is based on a doublet format, but as I said in an earlier
mail, the designer, Lou Varney, designed his antenna to work on the
original ham bands of 160/80/40/20/15/10 using a given length of top,
open wire feeder and specific LC network to match it to the transmitter.
When coaxial cable came in for amateur use, he then modified the design
to use a tail of cable to the shack and rethought his LC values to match
it.
So the G5RV varies greatly from a straight forward doublet.
Hence the answer to Jim's original inquiry is that (depending on the
exact wording on the packaging) that the antenna won't resonate on all
the ham bands, unless has an LC network associated with it.
If an ordinary tuner, whether it be manual or automated, is used, truly
the antenna ceases to be a G5RV and could then be argued to be a pure
doublet.
Further, the original measurements were based on a given type of wire,
and so those measurements would have to be modified according to the
specification of the wire used for the construction of Jim's antenna.
I seem to recall that the original was made from 14 gauge hard drawn
copper.
David
In message <[log in to unmask]>, David R. Basden
<[log in to unmask]> writes
>There is nothing magic about 51 feet each side of center. You could make the
>legs longer and cover 160 meters. The ladder line or twin lead combines with
>the wire portion to effectively lengthen the elements. If you increase each leg
>of the wire portion so that the twin lead plus wire length is sufficient for 160
>meters, it should tune without a problem.
>
>Dave, A F 6 Y
>
>At 03:25 PM 3/15/2004, you wrote:
>>They'll go to 80 no problem, just about everyone I talk to around here goes
>>to 80 with a G5RV, 160 is out of the question though.
>>----- Original Message -----
>>From: "Dave Hillebrandt" <[log in to unmask]>
>>To: <[log in to unmask]>
>>Sent: Monday, March 15, 2004 6:18 PM
>>Subject: Re: g5rv antenna
>>
>>
>>> Now, that could posibly say that it can be tuned on all bands because it
>>at
>>> least doesn't brag tuning bands that it is too short for. i think 20
>>meters
>>> was the only band that i found to really be fairly flat but it is a good
>>> antenna and with a tuner, even an auto tuner, i believe it will tune at
>>> least through 40 quite nicely. not so sure about 80 meters though. Dave
>>W4CI
>>> ----- Original Message -----
>>> From: "Butch Bussen" <[log in to unmask]>
>>> To: <[log in to unmask]>
>>> Sent: Monday, March 15, 2004 11:57 AM
>>> Subject: Re: g5rv antenna
>>>
>>>
>>> > ou'll need a tuner on all bands. I don't know why the paper would say
>>it
>>> > is falt on all bands. no way!!!
>>> > 73s
>>> > Butch Bussen
>>> > wa0vjr
>>>
--
David W Wood
|
