I have an AV-5 airband antenna [1] hooked-up to my scanners, and it
just struck me that (doh!) I didn't tune it before I installed it.
Looking at their docs, I was horrified to see that the supplied length
of the elements is such that it's way off tune. From my math, it'll be
tuned to around 95MHz instead of the 125MHz that would be the rough
center of the airband. How big a deal is this? Do I have to get the
ladder out again? Or will the losses be managable in an rx-only
application?

[1] http://www.rami.com/gaa/antenna-info.cfm?pid=15

I don't think I'd worry about it all that much. It seems to be fairly
broadbanded, so I doubt that in a receive-only environment you would notice
any difference. I would believe that you would only have an issue if you
were on the very edge of the receiving range for whatever particular station
you wanted to monitor. In that case, having it "properly tuned" MIGHT get
you that extra tiny bit of signal to make the difference between hearing and
not, but even that is iffy.


"Mike Granby" wrote in message
oups.com...

I have an AV-5 airband antenna [1] hooked-up to my scanners, and it
just struck me that (doh!) I didn't tune it before I installed it.
Looking at their docs, I was horrified to see that the supplied length
of the elements is such that it's way off tune. From my math, it'll be
tuned to around 95MHz instead of the 125MHz that would be the rough
center of the airband. How big a deal is this? Do I have to get the
ladder out again? Or will the losses be managable in an rx-only
application?

[1] http://www.rami.com/gaa/antenna-info.cfm?pid=15

From my experience, the more 'metal' you get in the air for receive the
better.
If you doubt this try attaching a long wire to your receiver and see for
yourself
'tuned' antenna's sound good on paper and as great advertising 'gimicks' but
an 8 inch tuned
antenna will not out perform a 120 feet of long wire (for receive).

and before any of you 'howl' about antenna design, etc etc .... go try it
then leave me a message


"Mike Granby" wrote in message
oups.com...

I have an AV-5 airband antenna [1] hooked-up to my scanners, and it
just struck me that (doh!) I didn't tune it before I installed it.
Looking at their docs, I was horrified to see that the supplied length
of the elements is such that it's way off tune. From my math, it'll be
tuned to around 95MHz instead of the 125MHz that would be the rough
center of the airband. How big a deal is this? Do I have to get the
ladder out again? Or will the losses be managable in an rx-only
application?

[1] http://www.rami.com/gaa/antenna-info.cfm?pid=15

Yeah, I would have thought that while a properly tuned antenna will help
you, it is nowhere near as critical as if it was hooked up to a transmitter
where a bad SWR can be costly / lead to bad transmission performance.

However because you aren't transmitting, I wouldn't say it is a critical
issue but still an issue that could matter in the longer term.

I've been using poles geared for lower end frequencies and while they do a
great job for those frequencies, even the stock standard antenna that came
with my handheld does a better for the 400MHz+ range that I've been
focussing on in recent weeks. I guess I'm just hooked on the awesome look
of lower frequency antennas!!

However if I was you I'd wait for advice from others before you get the
tinsnips out.

Neil



"Mike Granby" wrote in message
oups.com...

I have an AV-5 airband antenna [1] hooked-up to my scanners, and it
just struck me that (doh!) I didn't tune it before I installed it.
Looking at their docs, I was horrified to see that the supplied length
of the elements is such that it's way off tune. From my math, it'll be
tuned to around 95MHz instead of the 125MHz that would be the rough
center of the airband. How big a deal is this? Do I have to get the
ladder out again? Or will the losses be managable in an rx-only
application?

[1] http://www.rami.com/gaa/antenna-info.cfm?pid=15