Hi Eric and others, Thanks for the info. We are wanting something portable
but not as to carry them around. Just something we can transport with out to
much trouble, The repeater puts out about 25 watts. I guess thats why most
use UHF gear for this.
Randy
----- Original Message -----
From: "Eric Lemmon" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Saturday, April 22, 2006 12:34 PM
Subject: RE: [Repeater-Builder] Duplexer Wanted
> Randy,
>
> You won't find such a duplexer for a 600 kHz split. Mobile duplexers are
> notch-only, with no bandpass action at all. As such, they are almost
> useless for anything below a 5 MHz split. Even the larger "compact base
> station duplexers" such as the Celwave 5085 series are generally no good
> below a 3 MHz split.
>
> One of my local ARES groups has a "portable" 2m repeater that uses a
> Telewave TPRD-1454, 4-cavity Bp/Br duplexer that works fine with the
> low-power Hamtronics repeater. It's built into a foot-locker sort of
wooden
> box that can be carried by two men- more like transportable than portable.
>
> My CommShop program calls for about 77 dB of isolation between a 5 watt
> transmitter and a 0.35 uV receiver at a 600 kHz split, and this is exactly
> the specification of the TPRD-1454 duplexer. For 10 watts TX power,
you'll
> need about 80 dB of isolation. At 2m, a very small duplexer is simply not
> practical.
>
> The 2m coordination group in my area of California, TASMA, wisely set
aside
> one wide-spaced frequency pair for short-term portable repeater usage.
This
> pair is 147.585 MHz input and 144.930 MHz output, for a split of 2.655
MHz.
> This is within the capability of a Celwave 5085-1 compact base station
> duplexer, when ordered tuned on this pair from the factory. I am
assembling
> a portable repeater using this duplexer and a Motorola R1225 10-watt
> full-duplex radio. The entire repeater fits into a case that is less than
> one cubic foot in volume and can be carried with one hand. The Celwave
5085
> duplexer is about 50% larger than a typical mobile duplexer, and it comes
in
> models for both 3 MHz and 5 MHz splits.
>
> 73, Eric Lemmon WB6FLY
>
>
> -----Original Message-----
> From: [email protected]
> [mailto:[EMAIL PROTECTED] On Behalf Of Randy
> Sent: Saturday, April 22, 2006 8:12 AM
> To: [email protected]
> Subject: [Repeater-Builder] Duplexer Wanted
>
> We are looking for a Mobile type duplexer for a portable Repeater.
> tuned to 147.015 tx and 147.615 rx. If anyone has one or knows where we
> can get one please let me know, Thanks
>
>
> Randy
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> Yahoo! Groups Links
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> Yahoo! Groups Links
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