Michael Cox wrote:
Will this Duplexer work with the Mastr II repeater?
http://cgi.ebay.com/UHF-50W-6-CAVITY-DUPLEXER-FOR-REPEATER-FREE-TUNING
<http://cgi.ebay.com/UHF-50W-6-CAVITY-DUPLEXER-FOR-REPEATER-FREE-TUNING_W0QQitemZ350300447727QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item518f88a3ef>
Sure, it would work. It's a six cavity unit capable of providing enough
isolation for desense free operation with a receiver of -116 dBm and a
50 watt transmitter at a 5 MHz TX to RX spacing - as long as you aren't
in a crowded RF environment.
Would I recommend it? - absolutely not. As I and others have
mentioned, a BpBr design, (like the WP-678 I referenced in an earlier
mailing) would be a much better choice. Why? You'll likely buy a 100
watt PA to go along with your recent repeater purchase, and likely some
day you'll want to add a receiver preamp for hearing the real weak
ones.... The duplexer must provide enough RF isolation so the receiver
can hear a very weak signal, while, at the same instant, putting out
several watts from the transmitter so people can hear it. Look at it
this way, let's say you are listening for a pin to drop on a cushioned
floor while someone is shouting into your ear. The duplexer allows you
to 'tune out' the person shouting - giving you the ability to hear the
pin drop. This can only happen because the transmitter and receiver are
on two distinctively separate frequencies and the duplexer is optimized
for those exact frequencies.
There are places to save money where building a repeater is concerned.
The duplexer is not one of them. This doesn't mean you can't save money
- you can. The $250.00 WP-678 I spoke of in an earlier mailing was
about $800 to $1000 new. I'm recommending you buy $800.00 technology
not $79.00 technology.
Kevin Custer
