LM Ericsson, Sweden (the old telephone manufacturer) had a patent many years
ago regarding double contacts in relays. They showed that the reliability of a
relay was major increased when you had two relay contacts in parallel. I
believe you still find a term for this, just can't remember what.
Hans - N2JFS
In the "for what it's worth" columb. - I once heard that since precise
simultaneous closing and opening of the two contacts cannot be guaranteed
when just paralleling two circuits, the instantaneous current flow/arcing
contact damage may be the same for one of the contacts in a two contact
configuration as for the single contact.configuration. Obviously the longer
term I^2 R loss/heating would be improved but if one contact was welded by
the initial arc........
Gene / W2LU
----- Original Message -----
From: "Jim Lux" <jimlux@earthlink.net>
To: <richard@karlquist.com>
Cc: "Van K7VS" <wa7fab@cdsnet.net>; <towertalk@contesting.com>
Sent: Monday, September 27, 2010 11:20 PM
Subject: Re: [TowerTalk] X99KP 12VDC RELAY FOR AMERITRON REMOTE
ANTENNASWITCHES
-----Original Message-----
From: Gene Fuller <w2lu@rochester.rr.com>
To: Jim Lux <jimlux@earthlink.net>; richard@karlquist.com
Cc: Van K7VS <wa7fab@cdsnet.net>; towertalk@contesting.com
Sent: Tue, Sep 28, 2010 10:20 am
Subject: Re: [TowerTalk] X99KP 12VDC RELAY FOR AMERITRON REMOTE ANTENNASWITCHES
In the "for what it's worth" columb. - I once heard that since precise
simultaneous closing and opening of the two contacts cannot be guaranteed
when just paralleling two circuits, the instantaneous current flow/arcing
contact damage may be the same for one of the contacts in a two contact
configuration as for the single contact.configuration. Obviously the longer
term I^2 R loss/heating would be improved but if one contact was welded by
the initial arc........
Gene / W2LU
----- Original Message -----
From: "Jim Lux" <jimlux@earthlink.net>
To: <richard@karlquist.com>
Cc: "Van K7VS" <wa7fab@cdsnet.net>; <towertalk@contesting.com>
Sent: Monday, September 27, 2010 11:20 PM
Subject: Re: [TowerTalk] X99KP 12VDC RELAY FOR AMERITRON REMOTE
ANTENNASWITCHES
> W8JI mentioned tat they have form X contacts. That is the two contacts on
> the armature are bridged permanently, and there's no separate connection
> to the armature. Sort of like a rf transfer switch. Reduces parasitic c
> from armature to coil, etc.
>
> On Sep 27, 2010, at 10:55 AM, "Rick Karlquist" <richard@karlquist.com>
> wrote:
>
>> Van K7VS wrote:
>>> THE X99KP 12VDC RSCo. SPDT RELAYS ARE MANUFACTURED BY A COMPANY IN
>>> CHICAGO
>>
>> The company is probably Magnecraft, in my old home town of
>> Des Plaines, IL, a suburb of Chicago. They show some
>> nice off the shelf relays for antennas. Maybe the
>> Ameritron has gold plated contacts as a special. That's
>> the only thing I can think of where the OTS relays
>> are less than optimum.
>>
>> Rick N6RK
>>
>> _______________________________________________
>>
>>
>>
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>
>
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