[Heath] HP-1144 PS QUESTION

[JF]

On 11/3/2017 11:59 AM, Alexander N. Gerli wrote:
> Hi, folks! I have two of these PSs, both work fine. But they have
>  different regulator PCBs. Both cases say HP-1144. I thought there
> was an -A version, but which PCB did that have? My Manual shows
> the PCB with the large screw-mounted diode. Which one is which?
> Thanks. 73,  Sandy AC1Y


I don't know if there ever were "A" and "B" named versions, but the 
first version of the HP-1144 did not have the "large screw-mounted 
diode". That diode was part of a field update modification kit which 
added crowbar over-voltage protection and modified the regulator 
circuitry; that large diode provides the crowbar's short to ground.
The mod. kit manual said the PS is model 830-33, Series 00835.

Later HP-1144's from the factory must have included those 
modifications and a new manual, so if your manual shows the large 
3-terminal screw-mounted diode then you have the updated version. The 
field update kit included a completely new PCB, regulator IC, caps & 
resistors, plus a new manual.

If your other HP-1144 is the old version, then I have its manual; let 
me know if you need some pages scanned. I seem to recall that the 
older regulator IC was somewhat unreliable and is no longer 
available; whether or not the newer regulator IC is still available I 
don't know.

73
John  KE5ZB