Paul Christensen wrote:
> My long-term plan for the SPE amp is to replace the output relay with a
> Gigavac GH-1 and input relay with an Aromat/Matsushita RSD-12V. The
> latter
> of which is now an obsolete part, but still available through AG6K, and
> some
> "bottom feeders" on the internet. However, my short-term fix works so
I recently built a homebrew QSK switch using the Gigavac GH-1 relay
in the 12V version at the RSD-12V relay. I tested the GH-1,
which is rated at 6 ms, and found that it pulled in in 4 ms,
applying 12V to the coil. I applied 24V to the coil for the
first 3 ms and reduced the pull in time to 2 ms. After the
first 3 ms, the voltage falls back to 12V. The whole circuit
runs on 12V only and uses a capacitive charge pump technique to
pulse the 24V on the GH-1. Simple RC timing circuits are used.
The RSD-12V relay is good for 2ms just applying 12V to it.
Power MOSFET's are used to drive the relay coils. It works
perfectly with my FT-1000.
There is a special "HAM" price of something like $86 for the GH-1
when you order by email directly from Gigavac.
Rick N6RK
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"160-meters is a band for men, not for sissies!" - SM5EDX
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