On Fri, 8 Feb 2013 09:08:47 -0500, "Tom" wrote:

Are any better than the others in cross frequency rejection? I want a high
gain antenna but nothing that would pull in too many high power operators
locally.

Sometimes there are pagers or text message providers who bleed onto two
meters, especially when a local ham transmits, seems to come in strong. Are
there any ways to reduce or eliminate the cross frequency intermodulation? I
like the idea of the 17 foot, no problem with height, height means gain,
gain sometimes means intermodulation.

The diamond X-510 has very good reviews,

Any ideas how to eliminate cross channel intermodulation with good antenna?
Or right antenna?

You're antenna isn't going to do much for removing excessively strong
signals, such as paging. The single best improvement you can do is to
lose your scanner, and get a better receiver with a better 3rd order
intermod (IMD3) specification. By the nature of the beast, scanners
are highly susceptible to intermod mixes in their front ends.

There are cavity and crystal notch filters, that will reduce the
signal levels around the paging transmitter frequency, without
affecting the operating frequency (much). Search for crystal VHF
notch filter or cavity VHF notch filter.
http://www.parelectronics.com/amateur.php
http://www.vk5zd.com/PagerFilter/Filter.aspx
Careful what you buy as some notch filers are receive only and will
blow up if you transmit through it.

You can also build a tolerable notch filter with a T-connector and a
1/4 wave coax stub:
http://dl4xav.sysve.de/coax.filter/coax-filter.html

There are also ham radio bandpass filters, such as:
http://www.dci.ca/?Section=Products&SubSection=Amateur-FAQ
A BPF has the advantage of removing multiple sources of IMD, from a
wide variety of off frequency sources, while the various notch filters
only remove one frequency.

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558