[Heathkit] Heath HP-23 question

[Kenneth G. Gordon]

Richard Franzson wrote:

> Also,  can someone please tell me why the newer HP 23 power supply has
> an option for voltage levels. And the old version HP 23 did not.

I forgot to answer this last part: the very first model of the HP-23 (one of 
which I just finished rebuilding) DOES have an option for the 250/300 
VDC voltage levels, but it is only available via a wiring change internal 
to the supply. When you are building the supply you connect a 
particular wire to one point for 250 VDC output, and to another point for 
300 VDC output.

Kees has told us about the development of the various versions. IMHO, 
the HP-23A (which you have) is the best choice because of its multiple 
outputs, switching, and breaker. 

My early HP-23 is the next choice, as it does have all the outputs of the 
HP-23A, but has no switch, nor breaker. In fact, I had to mount a fuse 
holder in mine since originally it used that somewhat dangerous dual-
fused plug for safety. I got rid of that and went to a three-wire cord and 
a slow-blow fuse in a chassis mounted fuse holder.

Later models don't have as many choices of voltage outputs.

Ken W7EKB