07-26-2015, 02:07 PM
Hi guys, I'm restoring an old 89B that I got a while back (its in terrible shape, but I'll get there). I've done a thread over on ARF - would it be helpful having it here as well? Its a full strip and rebuild - I'm happy to repost here, orjust the highlights with my questions (given it is a Philco). This is what I started with:
[Image: http://i241.photobucket.com/albums/ff222...ca96fj.jpg]
[Image: http://i241.photobucket.com/albums/ff222...miqvh1.jpg]
[Image: http://i241.photobucket.com/albums/ff222...rcem03.jpg]
[Image: http://i241.photobucket.com/albums/ff222...fmcihb.jpg]
I have a couple of problems, and I'll need a couple of parts that I haven't managed to track down here in New Zealand yet too.
First request is for a decent hi res scan of page 3 of Philco Service Bulletin 146-B if anyone has a copy - I have everything else I need, and I'm working from this 2nd-to-last-run circuit diagram http://www.philcoradio.com/tech/images/89v9.jpg (thankyou Ron
) as the actual run was questionable, although its a code 123. It just didn't fully match any run when I was checking the circuit but it had been monkeyed with quite a bit - so I made the call to push it up to a near final run spec (and if I could find a nice 350k switched pot I'd go to the final run) just because I didn't want the hassles of the 36 tube as an oscillator, and because I was going to have to fully strip it anyway. Surprisingly, all the coils were good except the 1st IF, which I got a new old stock replacement for.
Anyway, I'm hoping a decent image of the chassis layout will help me figure out where all the 0.05 and 0.09uF caps come from and go to because its a little confusing at the moment and certainly doesn't match the photos or notes I took to begin with (all the caps were bypassed with externals and the wiring was a huge mess).
I'm also after a tube shield - I have 2, just need to find a third...
And finally - I'm replacing the 2-wire power cord with a three-wire - adding an earth. Is it ok to just earth the chassis? Is there anything else I should do before doing that? I've replaced the original line filter caps with an X/Y safety cap block.
I'm sure there were more questions, and I'm sure there will be more yet
Cheers
Steve
[Image: http://i241.photobucket.com/albums/ff222...ca96fj.jpg]
[Image: http://i241.photobucket.com/albums/ff222...miqvh1.jpg]
[Image: http://i241.photobucket.com/albums/ff222...rcem03.jpg]
[Image: http://i241.photobucket.com/albums/ff222...fmcihb.jpg]
I have a couple of problems, and I'll need a couple of parts that I haven't managed to track down here in New Zealand yet too.
First request is for a decent hi res scan of page 3 of Philco Service Bulletin 146-B if anyone has a copy - I have everything else I need, and I'm working from this 2nd-to-last-run circuit diagram http://www.philcoradio.com/tech/images/89v9.jpg (thankyou Ron
) as the actual run was questionable, although its a code 123. It just didn't fully match any run when I was checking the circuit but it had been monkeyed with quite a bit - so I made the call to push it up to a near final run spec (and if I could find a nice 350k switched pot I'd go to the final run) just because I didn't want the hassles of the 36 tube as an oscillator, and because I was going to have to fully strip it anyway. Surprisingly, all the coils were good except the 1st IF, which I got a new old stock replacement for.Anyway, I'm hoping a decent image of the chassis layout will help me figure out where all the 0.05 and 0.09uF caps come from and go to because its a little confusing at the moment and certainly doesn't match the photos or notes I took to begin with (all the caps were bypassed with externals and the wiring was a huge mess).
I'm also after a tube shield - I have 2, just need to find a third...
And finally - I'm replacing the 2-wire power cord with a three-wire - adding an earth. Is it ok to just earth the chassis? Is there anything else I should do before doing that? I've replaced the original line filter caps with an X/Y safety cap block.
I'm sure there were more questions, and I'm sure there will be more yet
Cheers
Steve
