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Re: [TowerTalk] Budget 4-Pack

To: towertalk@contesting.com
Subject: Re: [TowerTalk] Budget 4-Pack
From: Greg <ab7r@cablespeed.com>
Reply-to: "Tower and HF antenna construction topics." <towertalk@contesting.com>
Date: Tue, 02 Mar 2010 19:54:51 -0800
List-post: <towertalk@contesting.com">mailto:towertalk@contesting.com>
I think their new 8 pack also ground the unused antennas.  I am 
considering this but still waiting for the software to be finished.

73
Greg
AB7R


On 3/2/2010 7:16 PM, Jim Thomson wrote:
> Date: Tue, 2 Mar 2010 12:08:54 -0600
> From: Stan Stockton<k5go@cox.net>
> Subject: Re: [TowerTalk] Budget 4-Pack?
>
> Barry,
>
> Two DPDT relays for each antenna - one for each rig.  Activating a
> relay by Rig A with one set of contacts disables the other rig from
> being able to activate the same relay for the same antenna and vica
> versa.  If you are also wanting to prevent the other rig from
> transmitting at all that is another box to build.  Let me know if this
> is enough info.  If not I'll draw it.
>
> Stan, K5GO
>
> ### That's not how my six-pack works.  The 6 x pack uses 3PDT
> relays.  12 x relays in all, 6 x for radio..'A'.... and 6 x for..radio..'B'
>
> ##  for a 4-pack, and 2 x radio's... a total of 8 x 3PDT  relays required.
> The 1st pole of each relay simply OPENS OFF the  coil of it's mating
> relay.  [ and vice versa].    IE: radio 'A'   can grab any 1 of the 4 x ants'.
> Radio 'B'   can grab any of the 3 remaining available ants.  IF radio
> 'B'  is set to the same ant as radio 'A'....[say ant 1] , then radio 'B'
>   relay #1'  will not operate !
>
> ##  It's a real simple mech interlock arrangement really. It also provides
> aprx 70-80db  isolation between radio A + B 's  main 2 x coax inputs,
> and 60 db between either radio and any ant port [ this one is real important].
>
> ###     http://www.arraysolutions.com/Products/sixpak.htm
>
> then click on.. 'users guide'      Then scroll way  down the user's  guide,
> and u will see the complete schematic !    Notice that the 1st pole of
> each relay only uses 2 x contacts  [the common and normally closed].
> The normally open contact is not used.. or depicted on schematic[pole1].
>
> These NC  contacts are wired to each other's coils.[interlock]. 
> Coil-NC-NC-Coil
> The remaining 2 x pole's of each relay are used to do the switching,, and
> provide HIGH isolation [when de-energized]  The 2 remaining poles have
> their  RF contacts wired in SERIES !
>
> ##  The high isolation comes about by  using the 2 x sets of
> contacts in series.  When  de-energized, the leakage path is
> Doubled. You have the stray C of each open contact, now in
> series with each other = 1/2 the stray C = higher isolation  compared
> to, if just one set of contacts used.    Hence the use of 3PDT  relay's
> and NOT  DPDT relays.   The 3PDT  relays used in the 6 x pack use
> gold plated contacts.  It will handle 5 kw cxr, no problem.
>
> ##  The  relays are mounted [soldered] onto PC board, and use strip line
> technology to ensure the swr is dead flat  from 160-6m. [ no comp caps
> used either]
>
> ##  One caveat with the 6 x pack.... being a 2 x 6 matrix switch means ALL
> 6 x ant ports, when NOT in use, have floating center conductor's !
>
> ##  IE:  radio 'A'  is on ant #3..... and  radio 'B'  is on ant #5....  ant 
> ports
> 1-2-4-6  have open/floating center conductor's.
>
> ##  when done for the night, and everything shut off, ALL  6 x ant ports
> are opened off.
>
> ## On my 15 kw rat pack, [ 1 x 6 remote switch]  ALL  un-used ants
> have their center conductor's GRNDED !   IE: all de-energized relays.
>
> later... Jim  VE7RF.... owner of 6 pack    SN  001
>
>
>
> On Mar 1, 2010, at 1:40 PM, "Barry Fox"<foxbw@comcast.net>  wrote:
>
>    
>> I have two HF radios and 4 different HF antennas.  I would like to use
>> each rig on any antenna, while obviously locking out that antenna for
>> the other rig.  The commercial products 6-Pack, 8-Pack, etc are way
>> over my budget.  Anyone have a schematic for a "4-Pack" or similar
>> device they would like to share?  Obviously relays are the way to
>> go, and I can get the RF relay switching part of it on paper but
>> not the lockout logic.  Some sort of electro-mechanical exclusive-OR
>> gate array / diode matrix?  Anyone been there and done that?
>> TNX / 73,
>> Barry - W1HFN
>>
>>      
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