[Elecraft] Gamma Research Very Small Switching Power Supply

[John Buck]

The voltage on my meter is 13.65 with no load.
With K2/100 set for 50 watts out the voltage drops to 13.3 with a string 
of 15 wpm dashes.
At 75 watts it drops to 12.75 volts.
At 100 watts it drops to 12.2 volts.

Due to the large capacitance, it takes several seconds to drop to the 
levels measured.  The voltage is slightly higher, I do have a fuse in 
series between the measurement point and the PS.
I do not recommend solid straight Key down for several seconds.  I have 
not tested it this way.
The power supply would probably fold back at some point.
This small amount of testing did not seem to heat the supply much.
The fan noise is much quieter than the computer under the desk.  I could 
not hear it at first.

The K2 does not seem to mind.  I would recommend a different PS if you 
want 100 Watt plus CW for extended periods.  If you want to run 100 watt 
ssb or 75 watts or so of cw and you want a small, quiet alternative to a 
battery then this seems to be a good choice.

It is basically a 35 watt commercial supply module with the addition of 
the very large output capacitors.  It is recommended for a max of 35 
watts continuous like RTTY, AM, FM modes

It is rated for 5 amps continuous or 22 Amps @ 25% duty cycle from the 
HPS-1a data sheet.
Perfect for 100 watt SSB and use good judgment for cw.

It is more compatible with my k2/100 than with the Orion.  The Orion 
does not like it at 100 watts CW.  50 watts seems ok

These are all the answers I know.  If you are interested but still have 
questions, you should contact WWW.Gammaresearch.net

John KH7T
no affiliation, just a happy customer.

Robert Tellefsen wrote:
> John
> Can you tell us how well regulated the output voltage
> seems to be between key up and key down?
> Thanks and 73
> Bob N6WG
>
>