Martyn wrote:
"Kerry Miller" wrote in message
newsBgEf.149059$WH.120009@dukeread01...

gb wrote:


"Kerry Miller" wrote in message
news:84YDf.148864$WH.136453@dukeread01...


Since I'm going to have to order a chip for that Astron PS I was working
on, I dug out another old PS that died a few years back. If I have to
pay shipping, I might as well order enough parts to at least make up for
the shipping costs...

Does any of you guys know where to find a schematic for a Yaesu FP-757HD
power supply? It has a 3-terminal regulator in it, it looks like a 317,
but it has funky markings on it which say B824, then down and to the
right it says Q5D. It might be an O or 0 (zero) 5D. Do you guys know if
you can replace this B824 thing with an LM317? The transistors are
oddballs too but I haven't gotten the number for them. If I have to, I
can just start from scratch on it, there's not much to it and there were
a couple of caps with the legs corroded off. I can probably just come up
with my own regulator as easy as I can fix this one unless I can find a
schematic.

Do you guys know where to find a schematic for this thing?

Tnx,
Kerry, WD5ABC


Here we go:

3 - Pass (NPN) transistors Q1 - Q3: 2SD717-Y
on heat sink

These 3 should be on PC board (AVR Unit PB-2156
Q101 - 2SK192-BL (looks like FET)
Q102 - 2SA1012Y (looks like PNP bipolar)
Q103 - 2SA950Y (looks like PNP bipolar)

Q102 drives the pass transistors
Q103 Base connected to VR101 for adjustment (voltage adjust?)

w9gb


Perfect, I got the schematic, thanks! Looks like there's not too much to
it. I picked up a few parts in San Antonio today for the Astron (I
thought it was fixed, but it's still not right). I'll have to think about
the Yaesu and see if I can find some of those parts or at least find what
they cross to.

Thanks for all your help!
Kerry


i have a schematic for the YaesuFP757HD power supply.
in the schematic there are no regulators, there are no IC's, just 5
bipolar transistors and a fet.
this is providing that they didn't update the circuit and you have a
newer one than me.
if you email me your address i will photocopy the schematic and post
it to you.

martyn preston G0THY


Martyn,

You're right, no regulators! W9GB sent me a schematic, but thanks for
the offer.

Thanks,
Kerry, WD5ABC