[Heath] SB/HW PS WANTED

[Kenneth G. Gordon]

On 19 Sep 2015 at 19:09, Alexander N. Gerli wrote:

> Hi, folks!
> 
> I am looking for an HP-23(whatever) in a SB-600 Speaker. I sold my 
> SB gear last year, and I just found a decent SB-102 so we're going 
> round the horn again. Gotta get a PS and one in a speaker cabinet 
> would be really nice.

Sandy:

Be aware that the FIRST model HP-23 has significantly lower HV than the 
later models. HV was something like 750 VDC at no load, while all later 
models output 820 VDC at no load. Also, the HP-23 requires a physical 
wiring change internally to switch the LV from low to high and vice-versa. 
There is no switch.

If you look carefully at the schematic of the HP-23 vs the later models, you 
will see that the AC output voltage for the HV is 20 volts lower (262 vs 282) 
for the later models.

The "best" model is the HP-23A, which has both the correct value of HV, and 
the other more versatile outputs. (Variable and fixed bias, LV switching, both 
6.3 and 12.6 V filament, etc.)

The B and C models were cost reduced versions.

However, for your SB-102, the "A" and later models would be quite sufficient.

Ken W7EKB