[R-390] MOV's and snubbers

[Roy Morgan]

On Jan 25, 2014, at 10:12 AM, Phil Mills <pmills7 at comcast.net> wrote:

> This begs the question……. The HA-1 keyer is most
> likely used for keying DC circuits.

Phil,

Yes, that certainly is the case.

>  Is that chart
> in the manual good for AC circuits?

Very good question, I suspect it was not meant for keying AC.

> Roy, thanks for pointing out that manual.  I used
> an HA-1 for several years and never paid any attention
> to that table or the need for a snubber.

You probably did not need to.  Most or all of the transmitters I’ve heard of being used with the HA-1 (HT-32, Ranger, Valiant, … ) have keying voltage and currents that figure out by the chart to need NO snubber for the mercury relay.  So no worries.

Roy


Roy Morgan
RoyMorgan at alum.mit.edu
K1LKY Since 1958