There is a "slight" flaw in the approach mentioned below. First of all
the SB220 relay runs at 125VDC. It is also a 3 pole device, one switches
the exciter , the other the output and the third controls the bias
circuit. Not very easy to do with even 2 Dow Keys AND very carefull
adjustment of the aux contacts even if you could find ones with a 125VDC
coil.
A reasonably close replacement relay is available thru the Newark catalog
and others. An alternative, if the coil is OK, is to use one good set of
contacts (they cant all be bad??) to control another relay with a 12VDC
coil for instance. (12VDC 3PDT relays are pretty cheap surplus). The
12VDC can be obtained from the 5V filament xfmr, a halfwave tripler and a
3 terminal regulator...cheap and simple.
If the SB220 coil is bad it is still fairly simple to wire in 12VDC
relays and keep all functionallity. Please E-Mail me direct for details
so as to not bog down the group.
73....Carl KM1H
On Mon, 10 Mar 1997 14:49:07 -0800 (PST) "David B. Ritchie"
<dbr@alumni.caltech.edu> writes:
>
>Lots of relays will work -- the one used by Heathkit in the SB220
>never
>quit on me, but I always viewed it as a weak link. Why not just go
>with
>a Dow Key, Amphenol or Transco -- these are widely available and
>bullet
>proof and should readily fit in the available space (they generally
>require connectors, though). For a less bullet proof solution, Henry
>still makes amps and I recall that they had a similar approach to
>Heathkit -- they can be reached at 1-213-820-1234; alternatively,
>similar
>types of relays are available from the standard electronics supply
>houses, e.g., Mouser, Jade, and Newark (order a catalog from Newark at
>
>1-800-298-3133 x48 -- its not quite 1500 pages long!).
>
>Anyway -- good luck
>Dave N7UE
>
>
>
>
>On Mon, 10 Mar 1997, Chris Pedder wrote:
>
>> Hi there,
>>
>> A friend of mine, very much an old timer and not on this mode, is
>looking
>> for an antenna relay for his SB220. He tells me that he has had no
>joy
>> getting one in UK and I wondered whether there was anyone on this
>reflector
>> who could point him, through me, in the right direction?
>>
>> 73,
>>
>> Chris
>>
>>
>>
>> ________________________________________
>>
>> Chris Pedder G3VBL/8P9EM
>> E-mail g3vbl@netcomuk.co.uk
>> AX25-mail g3vbl@gb7bnm.#45.gbr.eu
>> DX-Cluster g3vbl > gb7dxd
>> ________________________________________
>>
>> --
>> FAQ on WWW: http://www.contesting.com/ampfaq.html
>> Submissions: amps@contesting.com
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>> Problems: owner-amps@contesting.com
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>>
>
>David B. Ritchie, Esq.
>D'Alessandro & Ritchie, P.C. -- Intellectual Property Lawyers
>3521 E. Yorkshire Road, Pasadena, CA 91107-5432
>818-683-8800 (TEL) 818-683-8900 (FAX) dbr@alumni.caltech.edu
>
>
>
>
>--
>FAQ on WWW: http://www.contesting.com/ampfaq.html
>Submissions: amps@contesting.com
>Administrative requests: amps-REQUEST@contesting.com
>Problems: owner-amps@contesting.com
>Sponsored by: Akorn Access, Inc. & N4VJ / K4AAA
>
--
FAQ on WWW: http://www.contesting.com/ampfaq.html
Submissions: amps@contesting.com
Administrative requests: amps-REQUEST@contesting.com
Problems: owner-amps@contesting.com
Sponsored by: Akorn Access, Inc. & N4VJ / K4AAA
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