[CQ-Contest] Receiving Antenna Splitter and Switching SystemQuestion

[Tom W8JI]

I use this system:

http://www.w8ji.com/images/New%20Contest%20Room/Contest%20station%20CQWW2007/receiver-switch-matrix.jpg

Except now I have PC boards laid out....the PC boards I have are cascadable, 
so they will build into a system as large as required in multiples of two. 
For example, I can do a 8x10 matrix or anything else.

It has magic T splitters, and splits six inputs into four outputs.

The controls for receivers look like this:

http://www.w8ji.com/images/Shack/RX-ant-select.jpg

In the house, the matrix is 7 antennas to four channels. I have Eu Bev rear, 
Eu Bev Front, Bev rear 8 directions, Bev front 8 directions, Eu verticals, 8 
direction 8 antenna vertical array, and a spare port that can be assigned 
any new antenna array.

Pulling one plug and inserting another changes the system from house to the 
barn. It now takes about a minute to change from house use to barn use.

I can transmit on 160 and receive at the same time, so dynamic range is 
good, but I do have wide antenna separation. On 40 I can get into band noise 
floor ~3 kHz off my own transmitter.

My system is all 75 ohm, because the cable is very good, cheap, and very 
easy to use, and because very few receivers actually measure 50-ohm anyway. 
The receiver leads are all 75 ohm miniature coax.

73 Tom




----- Original Message ----- 
From: "Dave Hawes" <dave.n3rd at verizon.net>
To: <cq-contest at contesting.com>
Sent: Sunday, December 18, 2011 5:26 PM
Subject: [CQ-Contest] Receiving Antenna Splitter and Switching 
SystemQuestion


> Hello, contesters.
>
> At our M/2 station, we are adding RX antennas and operating positions, and
> have outgrown our homebrew "six in, four out" RX antenna switching system.
> This system takes each of six RX antennas, and splits it four ways using a
> symmetrical 50 ohm power divider circuit (tnx W1FV), and relays to select 
> the
> desired RX antenna for each of four operating positions.  Unselected 
> antenna
> positions are terminated in 50 ohm resistors.
>
> We have added several more RX antennas and also are now up to six
> operating positions, so we need a solution.
>
> What are you guys with multi-op stations doing to split and distribute 
> your
> receiving antennas to your operating positions?
>
> I will summarize any direct responses.
>
> 73 - Dave N3RD
> At the N3RS M/2 Station
> _______________________________________________
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