Two Antenna Mounting Proximity?
 

Any performance issues I need to be concerned about when putting up two
rooftop antennas (a 2-Meter xmit/rcve Firestik and a rcve only wideband AOR
SA7000) in close proximity to one another? I'm thinking about using my
chimney chase which would allow at most a couple feet separation between
the two. How about the affect of other objects such as a metal chimney flue
cap?

Thanx,
Bob

"Bob" wrote in message . 14...
Any performance issues I need to be concerned about when putting up two
rooftop antennas (a 2-Meter xmit/rcve Firestik and a rcve only wideband AOR
SA7000) in close proximity to one another? I'm thinking about using my
chimney chase which would allow at most a couple feet separation between
the two. How about the affect of other objects such as a metal chimney flue
cap?
================================================== =======================

You didnt say whether you would be using the 2 mtr antenna for
xmitting. If both are for recieving the antenna placment wont make
much difference. If you are going to be xmitting on the 2 mtr antenna
then the other antenna "should" be 1/4 wavelength away from it in
order for it not to ineract with it. For 2 meters that would be about
19"s. As long as the antennas are above the flue itself that wont be a
problem. If you are going to be xmitting on the 2 mtr.ant. you're
going to have some significant rf induced into the other antenna, so you
might want to keep that in mind when operating.

Jeff

If your planing to xmit with the two meter antenna then disconnect the
receiver
from the other antenna's co-ax cable at the receiver input while transmitting
This will avoid e transmitter Radio Frequency energy (rf) burn out in the
receive. A
co-ax switch at the receiver's antenna jack would be a good way to keep the rf
out if the receiver.
Just remember to switch the receiver antenna off or out of the co-ax line.

There was a 'professional' grade scanner made for emergency vehicles that
had this antenna switch
in the form of a pull down relay built into the scanner. It was activated by a
cord that would go to a
connector on so equipped transceivers collocated in the emergency vehicle. So
when the mike was
'keyed' the scanners antenna would be cut out to avoid rf burn out!
Jim
Bob wrote:

Any performance issues I need to be concerned about when putting up two
rooftop antennas (a 2-Meter xmit/rcve Firestik and a rcve only wideband AOR
SA7000) in close proximity to one another? I'm thinking about using my
chimney chase which would allow at most a couple feet separation between
the two. How about the affect of other objects such as a metal chimney flue
cap?

Thanx,
Bob

If you're remembering the Uniden MR-8100 - if I remember it correctly
it was simply a speaker mute - it did not disconnect the antenna. It
was simply there to prevent audio feedback....




On Tue, 18 Nov 2003 21:54:43 -0500, Jim Mac Donald
wrote:

If your planing to xmit with the two meter antenna then disconnect the
receiver
from the other antenna's co-ax cable at the receiver input while transmitting
This will avoid e transmitter Radio Frequency energy (rf) burn out in the
receive. A
co-ax switch at the receiver's antenna jack would be a good way to keep the rf
out if the receiver.
Just remember to switch the receiver antenna off or out of the co-ax line.

There was a 'professional' grade scanner made for emergency vehicles that
had this antenna switch
in the form of a pull down relay built into the scanner. It was activated by a
cord that would go to a
connector on so equipped transceivers collocated in the emergency vehicle. So
when the mike was
'keyed' the scanners antenna would be cut out to avoid rf burn out!
Jim
Bob wrote:

Any performance issues I need to be concerned about when putting up two
rooftop antennas (a 2-Meter xmit/rcve Firestik and a rcve only wideband AOR
SA7000) in close proximity to one another? I'm thinking about using my
chimney chase which would allow at most a couple feet separation between
the two. How about the affect of other objects such as a metal chimney flue
cap?

Thanx,
Bob