[Amps] Reed Relay for QSK

[Paul Christensen]

> I'm modifying a SB-220 for QSK per Richard Measures' (AG6K) design which
> calls for a Matsushita RSD-12v reed relay for switching the amp input, and
> it looks like they are obsolete, so I'm unable to easily find one.  '

Rich, AG6K still sells them.  Th RSD-12V went through several changes in 
manufacturing, beginning under the Panasonic Matsuhita name, then Aromat, 
and ended up under Panasonic Electric Works (PEW) name at the time it was 
discontinued.

Another option is to compare the RSD-12V specification sheet with similar 
signaling relays in the PEW line:

http://www.panasonic-electric-works.de/pewde/de/downloads/ds_61015_0000_en_r.pdf

In particular, I would try to match-up the relay's "operate time" parameter 
of 3 ms. or less.  One possibility is the AGN or AGQ series as its pull-in 
and release time with a snubbing diode is comparable to the RSD-12V.  The 
RSD-12V's contacts are AuCo, while the AGN/AGQ series uses AgPd.  I know 
next to nil about metallurgy, so perhaps other folks can speak as to the 
contact composition for RF switching purposes.

http://panasonic-denko.co.jp/ac/e_download/control/relay/signal/catalog/mech_eng_gn.pdf

Paul, W9AC