Perhaps the best answer is to see what the public-safety agencies use at
sites with several dozen UHF repeaters within a few hundred meters. In
my area of Central California, the most common repeaters are Motorola
Quantar and MTR2000, or Kenwood TKR-840. The brand of the repeater used
is driven by the brand of mobile and portable radios being used, since a
Kenwood mobile radio will not mute quietly on a Motorola repeater, and
(except for the Professional Series radios) vice-versa. While many GE,
Vertex, and Icom radios will mute quietly on a Kenwood repeater, that is
not a "given."
While selecting top-quality equipment is important, there is a great
deal of engineering that must go into the design of a repeater at a
dense site. Logical placement of antennas is important; you don't want
to put your antenna right next to an antenna that has a harmonic or
subharmonic relationship to yours.
My personal preference is to use large-diameter cavity bandpass filters
on both RX and TX, double or triple ferrite circulators on TX, and
nothing but double-shielded cable or hardline throughout. The Number
One Rule is that nothing but an on-frequency signal can get into my
receiver, and nothing but an on-frequency signal leaves my transmitter.
In an ideal world, all of the repeaters at a dense site would be
designed to follow this Rule. Alas, such is not the case...
73, Eric Lemmon WB6FLY
mbloom0947 wrote:
>
> I suspect that many of the participants here have had experience
> selecting UHF repeaters for high-RF applications such as at
> broadcasting sites. Which would you buy and why? Yaesu/Vertex,
> ICOM, Kenwood, or some Motorola type? At present I am using a pair
> of Moto GM300s with a RICK controller.
>
>
> Yahoo! Groups Links
>
>
>
>
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