I think I would have to take out a second mortgage just to pay for the 20
Vacuum Relays! ;>)
Mike Baker K7DD
k7ddmjb@qwest.net
-----Original Message-----
From: towertalk-bounces@contesting.com
[mailto:towertalk-bounces@contesting.com]On Behalf Of OM7ZZ
Sent: Wednesday, January 05, 2005 6:55 PM
To: Jim Lux; towertalk@contesting.com
Subject: Re: [TowerTalk] Help need Vacuum Relay Isolation 1.8 to 30
> Of course.. but, in any case, they are transmission lines, as opposed to
> casually chosen pieces of copper.
Yes, you are right, transmission lines at a given impedance providing match
to 50ohm.
Hardest task was a design of this striplines. 7/16DIN antenna connectors are
in circle layout with diameter 43cm (17in).
73 Jozef OM7ZZ
----- Original Message -----
From: "Jim Lux" <jimlux@earthlink.net>
To: "OM7ZZ, Jozef Urban" <om7zz@stonline.sk>; <towertalk@contesting.com>
Sent: Thursday, January 06, 2005 1:56 AM
Subject: Re: [TowerTalk] Help need Vacuum Relay Isolation 1.8 to 30
> At 04:22 PM 1/5/2005, OM7ZZ, Jozef Urban wrote:
> >Yes Jim.
> >Little blue relays are used for switching of power vacuum relays.
Principle
> >is same as used at serialy produced little brothers of this switches -
> >Double Ten and Double Six. Diagram of one port is available at:
> >http://www.microham.com/double%20ten%20switch%20features.html
> >Strip star cannot be at 50ohm because arms to unselected ports creates
open
> >stubs and affects matching. Correct impedance is higher and has been
> >obtained experimentaly.
>
> Of course.. but, in any case, they are transmission lines, as opposed to
> casually chosen pieces of copper.
>
>
> >-70dB of isolation is a value who can be obtained relative easy with most
of
> >relays suitables for RF switching if two are used in line. As Tom said,
very
> >important is a grounding and proper layout.
> >
> >73 Jozef OM7ZZ
>
>
-=x=-
Skontrolované antivírovým programom NOD32
_______________________________________________
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_______________________________________________
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
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