On 12/25/2010 6:52 AM, Howard Hoyt wrote:
> Howdy and Merry Christmas all,
>
> I maybe restating common knowledge here, but I just discovered that
> Gigavac has a special program to sell HV/RF relays to hams directly at a
> really reasonable cost:
>
> _http://www.gigavac.com/products/relays/ham/index.htm
> <http://www.gigavac.com/products/contactors/datasheets/gx14/index.htm>_
>
I can report that the ham purchase program works as advertised
for about $85. I bought the 12V version and rebuilt
my homebrew QSK circuit for my linear. I used the speed up circuit
shown here:
http://members.cruzio.com/~k6xx/radio/fastrely.pdf
Using this, the turn on time is less than 5 ms.
Although this circuit doesn't speed up release,
it was already under 10 ms.
The whole thing runs on +12V including the reed
relay for the radio.
I had previously used Rich Measures' QSK circuit,
which was very inconvenient because it required
100V, which I didn't happen to have (my linear runs on 48V).
I kept the reed relay from that circuit to use in the
new one. BTW, the reed relay doesn't need any speed up.
It's something like 2 ms from the factory.
The 28V vacuum relay in that circuit failed.
I had bought it surplus, used. I think its worth the
extra money to get a new one.
The dimensions of the current relay are slightly different
from my old surplus one. I had to slightly enlarge the
mounting hole. They converted to metric dimensions.
The new relay still has the same flimsy coil connections,
be real careful you don't bust them off.
Rick N6RK
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