[Yaesu] Help please with FT4021B

[w6jzr]

I recently acquired an FT401B, S/N 5D323044, because it is similar to =
the FTDX401 that was my first SSB XCVR in the early 70's. In fact the =
original manual that was supplied is actually for an FTDX401, except for =
the schematic. I would appreciate some comments and opinions before I =
begin the restoration process.
1. The FTDX401 manual does not mention the AM mode, while the schematic =
for the FT401B includes the function. Can someone please comment on the =
correct tuning procedure for AM and is there any available documentation =
for the AM module shown in the schematic? Where is the best source for a =
proper manual?
2. I remember issues with sticking relays, as my FTDX401 aged, but are =
there any other notorious problems to look for?
3. What are the primary component failures to look for? I see no sign =
that this radio has ever been worked on, and in fact has all the =
original tubes.
A bench test showed some distortion on strong signals, indicating AGC =
problems, and a significant drop in output power during key down, =
probably due to "soft" original Toshiba finals.
4. I noticed that several of the tube shields seem to be frozen to the =
ground wire that goes between the tube and the tube shield. Are there =
any tricks to freeing these shields?
5. The plastic sheeting on the front face is still in tact, but very =
dirty and yellowed. Is it common practice to just remove this sheet, or =
can you actually replace it?

I look forward to any advice on restoring the fine Yaesu classic.
Thanks,

Bob/W6JZR

--- StripMime Report -- processed MIME parts ---
multipart/alternative
  text/plain (text body -- kept)
  text/html
The reason this message is shown is because the post was in HTML
or had an attachment.  Attachments are not allowed.  To learn how
to post in Plain-Text go to: http://www.expita.com/nomime.html  ---