[R-390] multiple receiver coupler

[Charles Steinmetz]

Mike wrote:

>I'm interested in buying/building a 1 in >=4 out receiver coupler, 
>HF only, receive only, >=0dB gain per port relative to the incoming 
>antenna signal.

If you decide to go passive, as some have suggested, here is some 
info that I posted back on 1/11/13:

>>If you go passive, you may also want to consider the passive 
>>splitters from Mini-Circuits.  IME, they have better isolation and 
>>amplitude matching than the Stridsberg splitters, and can handle 
>>higher input levels with less distortion.  They are also less expensive.
>>
>>ZFSC-2-6  (two outputs, 2 kHz to 60 MHz, $51.95)
>>ZMSC-4-1 (four outputs, 100 kHz to 200 MHz, $66.95)
>>ZFSC-8-1  (eight outputs, 500 kHz to 175 MHz, $99.95)


>I'd be happy to build something, either tube or solid state, if 
>anyone has a know-good design.

I use a Mini-Circuits ZFSC-8-1 preceded by a broadband preamp with 
9dB of gain (so overall gain is 0).  I have used a simple AD8010 
preamp as well as several high dynamic range discrete preamps of my 
own design at various times.  Besides bringing the gain up to 0, the 
preamp deals better with antennas that are not matched to 50 ohms 
than the naked input of a splitter does.  Another good feature is 
that you have a nice 50 ohm point to insert filters if you want.

Are the discrete designs better than the 8010?  Yes, but.  Unless you 
have a very strong local signal that would overload the 8010 (which 
will accept an input of +3.9dBm when configured for 9dB of gain), or 
band noise 40dB lower than anyone else on the planet, you won't 
notice any difference.

The preamp plus passive splitter scheme works significantly better 
than any other multicoupler I have tried, and I've used most of the 
usual suspects.

I will send you some documentation by direct email.

Best regards,

Charles