On Tue, 10 May 2005 18:39:16 -0700, Roy Lewallen
wrote:

Gary wrote:
I'm thinking of tossing up a G5RV and perhaps using it at times on 160
meters by shorting the braid and center conductor. What do I need for
buried radials ? Will several 40' - 50' radials work satisfactorially
or would one ~125' radial be best ? I could run a 125' radial but not
in a straight line

Several shorter radials will definitely be better than a single long one.

I'm planning on using No. 14 Ga solid insulated wire. I think I've
read in this newsgroup that the buried wire doesn't have to be bare ?

Yes, that's correct.

Also does anyone have a more elegant way of shorting the inner
conductor and braid together than the half axxed contraption I'd
cobble together ?

It's hard to say how to make something better than something for which
we have no description. Surely it can't be too hard to short two
conductors together.

Roy Lewallen, W7EL

One question, if shorting the leads to feed the g5rv "marconi style",
would it be better to connect the single wire to the antenna tuner's
random wire connection, or to the coax connection, or does it matter?

bob
k5qwg

It's hard to say how to make something better than something for which
we have no description. Surely it can't be too hard to short two
conductors together.

Roy Lewallen, W7EL

One question, if shorting the leads to feed the g5rv "marconi style",
would it be better to connect the single wire to the antenna tuner's
random wire connection, or to the coax connection, or does it matter?

bob
k5qwg


How much current will actually flow in the center conductor of the shorted
coaxial feedline? The single wire connection makes much more sense.

I never liked the G5RV antenna since it just seemed like a high loss method
of feeding a 102 ft piece of wire.

Frank
VE6CB

What is the basis of your "high loss method" statement?

"Frank" wrote in message
news:O7pge.61496$tg1.25181@edtnps84...

I never liked the G5RV antenna since it just seemed like a high loss
method
of feeding a 102 ft piece of wire.

Frank
VE6CB

"Fred W4JLE" wrote in message
...
What is the basis of your "high loss method" statement?

"Frank" wrote in message
news:O7pge.61496$tg1.25181@edtnps84...

I never liked the G5RV antenna since it just seemed like a high loss
method
of feeding a 102 ft piece of wire.

Frank
VE6CB

The following is based on an analysis I did for a ham Friend. Consider a 102
ft bent dipole (REF: Richards Antenna v4), fed in the center with 33ft of
300 ohm tubular, followed by 25 ft of 75 ohm twin.

Frequency Total feedline loss
(MHz) (dB)

1.8 24.8
3.8 4.9
7.1 2.4
10.1 10.2
14.1 1.4
18.1 3.0
21.2 9.1
24.9 2.7
28.5 3.9

If you are interested I can e-mail you the complete analysis in Microsoft
Word showing various feedline combinations from 1.8 to 30 MHz. If you have
a particular structure in mind I can also do the analysis. I use NEC2 based
software in combination with the ARRL's transmission line analysis program.

Regards,

Frank
VE6CB

Frank, with all due respect I disagree with your analysis. I would
appreciate your sending me the data so we may both start at the same
discussion point. will get the info to me.

73
Fred

"Frank" wrote in message
news:dYpge.61513$tg1.41377@edtnps84...

"Fred W4JLE" wrote in message
...
What is the basis of your "high loss method" statement?

"Frank" wrote in message
news:O7pge.61496$tg1.25181@edtnps84...

I never liked the G5RV antenna since it just seemed like a high loss
method
of feeding a 102 ft piece of wire.

Frank
VE6CB

The following is based on an analysis I did for a ham Friend. Consider a
102
ft bent dipole (REF: Richards Antenna v4), fed in the center with 33ft of
300 ohm tubular, followed by 25 ft of 75 ohm twin.

Frequency Total feedline loss
(MHz) (dB)

1.8 24.8
3.8 4.9
7.1 2.4
10.1 10.2
14.1 1.4
18.1 3.0
21.2 9.1
24.9 2.7
28.5 3.9

If you are interested I can e-mail you the complete analysis in Microsoft
Word showing various feedline combinations from 1.8 to 30 MHz. If you
have
a particular structure in mind I can also do the analysis. I use NEC2
based
software in combination with the ARRL's transmission line analysis
program.

Regards,

Frank
VE6CB

"Fred W4JLE" wrote in message
...
Frank, with all due respect I disagree with your analysis. I would
appreciate your sending me the data so we may both start at the same
discussion point. will get the info to me.

73
Fred

Thanks Fred, I am happy when people disagree with me, since then I have a
chance of learning something. I will e-mail you my analysis.

73,

Frank

Frank wrote:
How much current will actually flow in the center conductor of the shorted
coaxial feedline?

Good question. In this case, the more difference in the two
currents, the greater the radiation from the horizontal section.

I never liked the G5RV antenna since it just seemed like a high loss method
of feeding a 102 ft piece of wire.

Actually, if the purpose of the matching section is to lower
the SWR (and thus the losses) on the coax, it does a reasonable
job on 80m, 40m, 20m, and 12m. But forget the other four bands
unless you change the length of the matching section.
--
73, Cecil http://www.qsl.net/w5dxp

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Bob Miller wrote:

One question, if shorting the leads to feed the g5rv "marconi style",
would it be better to connect the single wire to the antenna tuner's
random wire connection, or to the coax connection, or does it matter?

It's hard to say, because too many variables are involved. What I'd do
is to model the antenna with EZNEC and if the impedance is high use the
random wire connection and if low the coax connection.

Roy Lewallen, W7EL