[TowerTalk] remote ant switch decision

[dw]

I've also used the surplus pulsed rotary switches with good success.
Had an 8-pole 9-throw unit I used for about 5 years switching an
external impedance match-box with 9 fixed L-networks in it.
Used a programmable PIC, to step it to a specific position, powered by
13volt supply.
As long as one keeps critters and weather out of it, pretty reliable.



On Wed, Apr 13, 2016, at 08:28 AM, Jim Hargrave wrote:
> Don't sell the surplus military antenna switches short. Mine is a small 4
> position rotary drum type fully enclosed.
> I have a homebrewed control box (24v) which now contains  a Binary
> decoder interfaced with Logger32. 
> It is still operating after 60+ years. They are not cheap, but very
> reliable.
> 
> http://lists.contesting.com/_towertalk/2009-03/msg00290.html
> 
> 73, Jim – w5ifp at gvtc.com
> 
> >> -----Original Message-----
> >> From: TowerTalk [] On
> >> Behalf Of J. Hunt via TowerTalk
> >> Sent: Tuesday, April 12, 2016 7:08 PM
> >> To: towertalk at contesting.com; Bob K6UJ <k6uj at pacbell.net>
> >> Subject: Re: [TowerTalk] remote ant switch decision
> >> 
> >> Great - I also agree with Joe, W4TV.
> >> 
> >> I have also replaced / upgraded many "open-frame" relays within
> >> transceivers / amplifiers / antenna switches over the years with
> >> appropriate sealed relays.
> >> The "open relays" I have replaced - exhibited the same failure type
> >> as described below.
> >> 
> >> My HF tower switch is home-brew.
> >> It features "N" connectors, computer controlled from station, with
> >> lock-out and feedback protection.
> >> Including integral lightning protection.
> >> Insertion loss <0.05db @ 50MHz., >60db isolation between ports
> >> (4).
> >> 
> >> About 10 years ago, I got fed up with pre-manufactured remote
> >> antenna switches.
> >> Problems, one lightning hit - toast, high insertion loss, with
> >> questionable isolation between ports.
> >> 
> >> 
> >> Thanks n 73,
> >> James
> >> ki5dq
> >> --------------------------------------------
> >> On Tue, 4/12/16, Bob K6UJ <k6uj at pacbell.net> wrote:
> >> 
> >>  Subject: Re: [TowerTalk] remote ant switch decision
> >>  To: towertalk at contesting.com
> >>  Date: Tuesday, April 12, 2016, 11:45 AM
> >> 
> >>  thanks Joe,
> >> 
> >>  Bob
> >>  K6UJ
> >> 
> >>  On 4/12/16 7:47 AM, Joe Subich, W4TV wrote:
> >>  >
> >>  > Stick with the switch that uses enclosed relays with higher
> >> impedance  > coils.  The "open frame" relays (even with a
> >> carbonate cover) with  > low impedance coils (higher current) are
> >> more sensitive to corrosion  > *and* resistance in control
> >> leads.  The "open frame" relays *will*  > become unreliable over a
> >> relatively short period of time.
> >>  >
> >>  > The better switches use enclosed relays, and at least in one case,
> >> > cast, moisture resistant enclosures rather than bent sheet metal
> >> > that is susceptible to moisture intrusion.
> >>  >
> >>  > 73,
> >>  >
> >>  >   ... Joe, W4TV
> >>  >
> >>  >
> >>  >> To:    towertalk at contesting.com
> >>  >> Subject:    [TowerTalk] remote ant switch decision  >>
> >> From:    Bob K6UJ <k6uj at pacbell.net>  >> Date:    Tue, 12 Apr 2016
> >> 00:56:48 -0700  >>  >>  >> I am considering getting either the Array
> >> Solutions RatPak or a DX  >> Engineering remote antenna switch.
> >> Any feedback on either of these,  >> positive or negative ?
> >>  >>
> >>  >> thanks,
> >>  >> Bob
> >>  >> K6UJ
> >>  >>
> 
> _______________________________________________
> 
> 
> 
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 Bw_dw at fastmail.net