On 21 May 2004 23:45:36 GMT, (JDer8745) wrote:

What u r describing is a "multi dipole".

I have used combo 75 and 160 fed with same RG58 and had no problems.

73 de Jack, K9CUN

Yeah, I suppose that would be the same as a multi-band dipole. I guess
I just assumed there would be an impedance mismatch if I did that.

73's

Ron, W1WBV

rhymer wrote:

On Fri, 21 May 2004 09:21:44 -0400, "Jack Painter"
wrote:

"rhymer" wrote
What is the best way to use one feed line for more than one dipole?
Or, is it better to use a coax switch in the shack?

Ron, your subject line "Two dipoles on one coax" implies the typical antenna
selector switch that leaves no question (of course you can do that). But the
message body asks about one feedline for more than one dipole as opposed to
the antenna selector. The two choices are so unequal that a comparison is
not possible.

I have no idea what you mean by "typical antenna selector switch".

Someone may explain here that they have connected more than one antenna with
a single feedline, but it flies in the face of proper operating procedure.
Most operators however do use antenna selector switches to provide more than
one antenna choice to a given receiver or transmitter. The individual
antennas always have their own individual feedline in those cases.

Yes, I was referring to more than one dipole on a single feed line (in
my case two dipoles 40 and 15).

Thanks, Ron

You might try something like this:

http://www.hamuniverse.com/multidipole.html

73, AC6XG

"rhymer" wrote in message
news
Yes, I was referring to more than one dipole on a single feed line (in
my case two dipoles 40 and 15).

OM,

Since a dipole will also work on the third harmonic of its design frequency,
it's very common to use a 40 M dipole on 15. You usually don't need a second
dipole to work 15 if you already have one for 40.

As other have pointed out, however, it's perfectly fine to put dipoles for
other bands on the same feedline: 20, 17, or whatever. The antenna that's
not in resonance presents a high impedance to the feedline, and the resonant
dipole takes the power.

HTH.

73, Bill

"rhymer" wrote in message
...
On Fri, 21 May 2004 10:22:20 -0400, "Tam/WB2TT"
wrote:
.................................................. .....
Is the 40m at a right angle to the 17m, or is the V separation
adequate?

The 40 is not at right angles. Only shifted horizontally enough to clear the
tree trunks and find suitable anchors for the ends. Vertically, there might
be 30 degrees separation, since the ends of the 17 go up, and the ends of
the 40 come down

Since you have to trim the lengths slightly (lowest frequency first), it
is

That is because the 40 has more effect on the 17 than the 17 does on the 40.
I am using a 1:1 balun. Not sure if that affects anything or not.

simplest to run EZNEC or some other simulation first.

Tam/WB2TT

Thanks muchly for that,

Ron, W1WBV

Yes I forgot to add that each antenna was 1/2 wave long.

Jack