Cecil Moore wrote:



The argument has always been about your coax-fed dipole antenna
Vs my G5RV antenna.

I'm afraid not Cecil. You are just one of many that seem to run those
things...


You missed the question...How would I know you do that unless you tell
me in advance...I'm not a mind reader...

My antenna is a G5RV. You said your dipole would beat "any" G5RV,
presumably including mine. Your ignorance of my G5RV didn't enter
into the discussion at the time. You didn't even slow down to wonder
if a well-designed G5RV might equal your dipole on 75m.

I think it would *still* probably slightly beat your antenna. I'm fairly
certain even your G5RV will not be a complete equal to my coax fed
dipole. But that is my opinion, and it's not worth 100 more posts to
argue about it. It's common knowledge a coax fed dipole on the low bands
can be in the range of 95% +- efficient as far as the whole system. You
claim to be in that neighborhood, and may well be. But I'd have to see
it to totally believe you would be effectively equal. I bet on the air,
you would still see a slight difference. Might be small, but I bet it
would be there. I still don't like the coax/choke/ladderline combo
despite your claims that they are totally lossless. If you were to run
ladder line the whole way, I'd have much less trouble believing you.


Yes. IF...But I will still prefer the coax fed dipole.

If the design flaws of the G5RV are fixed, we then shift from
performance to preference?

Well, I suppose, but I would still prefer normal dipoles.

Your antenna is different than the vast majority used if what you
say is true.

It's a well-designed G5RV, the best I know of. You said you dipole would
beat "any" G5RV by S-units.

No I didn't . I've clearly agreed with improvements it could be a lot
closer. "As in your's" You reposted it below yourself... But yes, I
will repeat...My dipoles will handily beat *most* G5RV's on 80m.
Probably even yours by a slight amount.


If you have improved yours, I'm glad. You may well have a decent
antenna. But you need to spread the word, because most other's that
are unmodified are still gonna be lame radiators.

I posted my actual measurements yesterday. To optimize a G5RV for 75m,
make the series section transformer 25 feet long and put a 1000 pf
capacitor in parallel at the coax/open-wire junction. The beauty is
that you still have the framework for an all-HF-band antenna. Take
away the cap and extend the series section to 36 feet and you have
a G5RV optimized for 40m and 17m, my favorite bands. It takes about
two minutes for me to make that change but it could be automated.

I guess thats great if you are worried about all bands...I'm more
worried about brute performance on the band I'd be actually using at
field day...We aren't discussing home antennas...I don't think they even
do 17m on FD...

What proposal do you
offer to correct the feedline deficiencies of the average storebought
windom, or OCF dipole on 40 and 80m?

The original windom, powered by a tube transmitter with a pi-net matching
network, was a pretty good antenna. For today's "Windoms", I would advise
everyone to feed OCF's with open-wire line, equipped with an excellent
choke, at a current maximum point, using whatever ratio balun is appropriate.
I had an OCF in college, fed with open-wire line, powered by a Heathkit with
a pi-net tuning network. It's feedpoint impedance on the harmonically related
bands was in the neighborhood of 300 ohms. Matching a tube final to 300 ohms
through a pi-net tuner is pretty much a no-brainer and relatively lossless.

I'll let all those tube rig users at field day in on this information.
But most I see use solid state rigs...But I'll pass this on anyway...
They most all are using the tuners, so only a feedline change will be
needed. I bet they still will have inferior radiating devices in the end
though.....
Myself, I think multiband 102 ft dipoles should be fed only with ladder
line...Why are you not using your cut ladder line method for G5RV's?
Enquiring minds wanna know...:/ Why would someone prefer a G5RV over
your normal 80m size all band ladder line fed antenna for FD on 80m?
Enquiring minds wanna know that too...:}
Actually, I could care less what people use at field day, I just wonder
why many I see seem to prefer semi-dummy loads when they have the room
to avoid it...It's gotten to where full size efficient antennas seem to
be the exception, not the norm. And most have never heard of you, or
your modifications, and many are not really into antennas that much,
except to know they have to string them up somewhere. So they just
semi-dummy load along, blissfully unaware it would seem...They don't
know what they miss, because many never try one, thinking they need all
those extra bands...A regular coax fed dipole is not fancy or gimmicky
enough I guess... Oh well..G5RV onwards folks! MK

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