Thread: Antenna spacing
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Old January 3rd 06, 03:52 PM posted to rec.radio.amateur.antenna
Dave Oldridge
 
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Default Antenna spacing

Allodoxaphobia wrote in
:

On Mon, 02 Jan 2006 14:33:18 GMT, Dave Oldridge wrote:
Chris W wrote in
news:IT3tf.45644$ih5.19066@dukeread11:

I want to put a short 2 meter yagi and a long 70cm yagi on the same
vertical mast. The 70cm will be a horizontally polarized, center
mounted 17' boom and the 2 meter will be a vertically polarized, end
mounted 6 foot boom. How far apart do they need to be? I will only
be transmitting with one at a time but one could be receiving and
the other transmitting, the 70cm will be for ATV receive only for
now.


A good rule of thumb is to separate them by at least a half-wave at
the lowest frequency. In this case that means about a meter (39")
apart.


Not when they are orthogonally polarized. They can be 0.000
wavelengths apart. I.e., in the OP's case, the 2M elements can be
_mounted_ on the 70cm's boom.


You're right. I didn't catch the polarization thing. In fact, building
them on the same boom would be quite workable.

--
Dave Oldridge+
ICQ 1800667