[Elecraft] K3 Typical TX Current Consumption

[Paul Christensen]

> The power supply used for these tests is an Hewlett Packard digitally
> controlled model 6652A with remote voltage sensing--the sensing leads
> are connected to the Anderson connector where it enters my K3.

Same here, Jack.  I recently purchased a used HP 6652A and use the sense 
leads in the same manner.  I run the K3 at 14.5 VDC and the 6652A is 
programmed to open at 16 VDC.

For those curious, the HP/Agilent 6652A is a programmable 25A, 0-20 VDC 
lab-grade supply.  It runs very cool, and is extremely stable.  It's also a 
linear pass-transistor design  ;-)   The 6652A replaces a 16-year-old Astron 
RS-35A.

On the used market, it's possible to find these supplies for about $400-$500 
in good operating and cosmetic condition.  I believe the new price is close 
to $6K.

The supply's fan runs a bit louder than I'd like.  I just completed a 
modification using a NTC thermistor, power MOSFET, multi-turn pot, and a 5W 
resistor in series with the fan lead.  Now, the fan only operates when the 
temp threshold is exceeded and when active, is no longer audible yet is 
still produces adequate cooling volume.

Hey, this is starting to sound like an eHam review, so I better stop here.

Paul, W9AC