[TowerTalk] Help need Vacuum Relay Isolation 1.8 to 30

[OM7ZZ]

> 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 at earthlink.net>
To: "OM7ZZ, Jozef Urban" <om7zz at stonline.sk>; <towertalk at 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
>
>


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