Topband: Receive Splitter or Not?

[Rick Karlquist]

Jim Brown wrote:
> On Mon, 23 Mar 2009 19:32:44 -0700 (PDT), Jim Murray wrote:
>
> An excellent company based in Brooklyn, Mini-Circuits Labs, makes
> very good passive splitters that do exactly what you want. The
> ZFSC-2-1W is a 2-way splitter that is specified for a minimum of
> 20dB isolation (30 dB typical) from 1 MHz to 750 MHz. The ZFSC-2-4
> is a 4-way splitter that covers 0.2-1,000 MHz with about 10dB less
> isolation. With both splitters, the loss is about 0.5dB greater
> than theoretical (3dB for 2-way, 6dB for 4-way).

It is important to realize that the splitter's isolation depends
on the source match.  If the receive antenna is far from 50 ohms,
you will not get much isolation, not matter what the spec says.
Most people don't worry much about source match of receive antennas
because it ordinarily doesn't matter much.  But it does matter in
this case.

Rick N6RK