When dealing with Yaesu (Vertex) it is worth the effort to contact
Vertex for special parts. There is a special regulator in the power
supply for the FT-301 that is no longer available. Contacting Vertex
led to a replacement subassembly for about $6. Not bad support for a
25 year old piece of equipment.



On Tue, 31 Jan 2006 23:56:11 -0600, Kerry Miller
wrote:

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
John Ferrell W8CCW