Topband: 'vacuum relay powering'

[Tom Rauch]

>
> If your station uses a common type, regulated power supply 
> with pass
> transistors, the 'basic supply' within usually measures 
> about 24 vdc
> across the electrolytic filter caps. This is where I 
> obtain my
> approximately 26.5 vdc for war surplus relays. Works like 
> a champ with
> good stiff regulation. I pick off the power via an in-line 
> fuse rated a
> few amps, RF by-passed where it exits the enclosure. A 
> simple, free
> source of 24 or "26" vdc, already existing.


I connect a simple cheap common wall wart in series with my 
normal 12 volt supply.

The real danger of running relays at low voltage (that still 
allows transfer) is they slow down on pull in times. Of 
course the release time speeds up!

Also, for anyone using QSK a backpulse diode across the 
relay will slow the release time down a good bit.

73 Tom