[CQ-Contest] Multi 2 locking device, TriPlexers and BPF

john at kk9a.com john at kk9a.com
Tue Jan 10 19:24:35 EST 2017

The 4O3A units have impressive specs but I wondering how important the extra
20+dB is. I have never observed an isolation issue with my Array Solutions

John KK9A

To:	cq-contest at contesting.com
Subject:	Re: [CQ-Contest] Multi 2 locking device, TriPlexers and BPF
From:	Jim Brown <k9yc at audiosystemsgroup.com>
Reply-to:	k9yc at arrl.net
Date:	Tue, 10 Jan 2017 14:28:45 -0800

On Tue,1/10/2017 8:23 AM, W0MU Mike Fatchett wrote:
Is there an "easy" way to improve the port Isolation in the WX0B six pack?

The only way I know of is replacement. I had one here, replaced it with
4O3A's 6x2, which was about 20 dB better (measuring both units on the
bench). Not long after that, 4O3A introduced the new 8x2, and I replaced the
6X2 with it. The 8x2 is more than 20 dB better than the 6x2, making it 45 dB
better than the WX0B unit. Isolation is 100 dB, +/- 3-4 dB, depending on
which band and which output.

Several years ago, I tried to get specs on the Microham unit. What I got,
eventually, was rather hard to read plots that showed that the BEST case
isolation of the 6x2 was quoted in the data sheet as "typical", and that
other ports were significantly worse (6-10 dB). I asked for a unit to
measure (to give them the benefit of the doubt), but W4TV insisted that I
buy one.

Bottom line -- the 4O3A 8x2 is the best I know of. It's very well built, the
control interface is close to being universal, and the guys in CO who
distribute it are great to deal with.

I've NOT given any attention to weatherproofing, because my switching is all
done in the shack. My bandswitching is being done by the band decoders in my
5B4AGN TXBPF filter sets.

73, Jim K9YC

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