Hi group,
just wondering.... can I take a 40M delta loop and add an 80M dipole to it?
Will there be interaction?
SWR problems?

Mark W4UDX

Mark,
Yes, to both.
'Doc

wrote:
just wondering.... can I take a 40M delta loop and add an 80M dipole to it?
Will there be interaction? SWR problems?

Actually, that should work pretty well. A loop has a very high
impedance on half its design frequency. Another thing to consider
is breaking the 40m loop opposite the feedpoint for operation on
80m. 1WL on 40m = 1/2WL on 80m.
--
73, Cecil http://www.qsl.net/w5dxp



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just wondering.... can I take a 40M delta loop and add an 80M dipole to it?
Will there be interaction? SWR problems?

Why not just increase the size of your loop to make it an 80 meter loop?? That
should cover 40m, at least thats what I've read...I'm in the process of
building my 80 meter loop which will hopefully work 10-80...Good luck..

Steve

"Desmoface" wrote in message
...
just wondering.... can I take a 40M delta loop and add an 80M dipole to
it?
Will there be interaction? SWR problems?

Why not just increase the size of your loop to make it an 80 meter loop??
That
should cover 40m, at least thats what I've read...I'm in the process of
building my 80 meter loop which will hopefully work 10-80...Good luck..

Steve


But remember a loop for 80 fed with coax will make for a high impedeance on
40.

If you feed this 80 meter loop with ladder line, open wire line, etc. You
can use it everywhere via a balanced output tuner of course.

Dan/W4NTI

Dan/W4NTI wrote:
But remember a loop for 80 fed with coax will make for a high impedeance on
40.

Higher, but not too high. A 2 WL loop is resonant in much the same way
that a 1 WL loop is resonant. Perhaps you are thinking about dipoles?
--
73, Cecil http://www.qsl.net/w5dxp



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But remember a loop for 80 fed with coax will make for a high impedeance on
40.

Yeah, you'd probably need to use a tuner but one wavelength on 80 is 2
wavelengths on 40, is 4 wl's on 20, 8 on 10....theoretically an 80 meter loop
should work great on 10-80 and the take off angle supposedly decreases as the
frequency increases...so it should be good at dx too..

Steve
kb8viv

"Cecil Moore" wrote in message
...
Dan/W4NTI wrote:
But remember a loop for 80 fed with coax will make for a high impedeance
on
40.

Higher, but not too high. A 2 WL loop is resonant in much the same way
that a 1 WL loop is resonant. Perhaps you are thinking about dipoles?
--
73, Cecil http://www.qsl.net/w5dxp

Two things to consider he

1. If you cut it for 3850, as an example, it will be way out of band on 40
meters (7700).

2. If you match it with a 1/4 wave section of RG11 on 80 meters, that will
be 1/2 wave on 40, and have no effect.

Having said all that, I find my Ameritron amp with a pi network output will
tune up on 40 meters. My loop is resonant at about 3800. Just in case, I
keep the power down.

Tam/WB2TT

1. If you cut it for 3850, as an example, it will be way out of band on 40
meters (7700).

Will it?? A full wave on 3850 is aprox 261 ft. A full wave on 7700 is aprox
130.52 feet. Looks pretty close to 2 wavelengths on 40..using the 1005/Freq
loop equation..

Again, my loop isnt up yet so I can't comment, I'm just going by equations on
paper...I'd expect a 2:1-3:1 swr on its resonant frq as it should see aprox 100
ohms....easily tuned out with the built in tuner in my rig...I would expect it
to work pretty good on 10-80 but will most certainly need a tuner to keep the
finals happy on freq's above 80....This is what I'm banking on LOL...Mine
should be up saturday..WOOHOO!!

Steve
kb8viv

Will it?? A full wave on 3850 is aprox 261 ft. A full wave on 7700 is aprox
130.52 feet. Looks pretty close to 2 wavelengths on 40..using the 1005/Freq
loop equation..


Woops, this is the eqation for a loop, not sure if it applies to a delta
loop..but it shouldnt be far off...

Steve
kb8viv