[kiwi_steve]

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

[kiwi_steve]

Oh - one more question... why do they run the two 0.015uF line filter caps permanently connected to the mains and not on the radio side of the on/off switch?  I'm considering moving them to the other side of the switch... any advice on that would be appreciated.

[Image: http://i241.photobucket.com/albums/ff222...5ayite.png]

Cheers

Steve

[Steve Davis]

Oh - one more question... why do they run the two 0.015uF line filter caps permanently connected to the mains and not on the radio side of the on/off switch?  I'm considering moving them to the other side of the switch... any advice on that would be appreciated.

The only reason that I can see for putting the line filter capacitors ahead of the switch is, when the switch is off, the voltage on the chassis will be limited to one half the line voltage. If the line capacitors were connected after the switch, with the switch off, the chassis will at zero or line voltage, depending on which way the plug is inserted into the receptacle. If you are installing a three wire cord, there would be no advantage for the caps to be ahead of the switch.

[morzh]

I am not sure those were the reasons. I think it was simply to save the switch as every time you connect the switch you would create an arc charging caps at zero volts. But when the caps are connected you connect an inductance and it is benign.
The fact the caps might stay charged was disregarded due to low overall capacitance (7.5nF).

[klondike98]

Hi kiwi, great to have you posting your restoration pics and questions here!!! Put your "wanted" requests in the "Wanted Ads" section please. More chance of a hit there.

[kiwi_steve]

Thanks guys - I will move the safety cap into the switched circuit along with the three-wire power cord.

I think I've finally nutted out the caps and I'm almost done with the partial rebuild underneath. I'll add some photos of the progress when I get a moment.

Cheers

Steve

[kiwi_steve]

Quick addition before bed... This is the before shot of the chassis, once stripped
[Image: http://i241.photobucket.com/albums/ff222...s9daiv.jpg]


And this is the after shot once de-rusted
[Image: http://i241.photobucket.com/albums/ff222...tnwcbh.jpg]


And after painting (which took 5 minutes, as opposed to the masking up that took over an hour!)
[Image: http://i241.photobucket.com/albums/ff222...wqlt3e.jpg]


And a final note before bed: never ever get curious as to how the tuning caps come apart... because really they don't  
[Image: http://i241.photobucket.com/albums/ff222...ii2cmw.jpg]

Steve

[morzh]

Nice job derusting, what did you use?

As for caps, other than usually not taking apart padders/trimmers part, they come apart very easily and are assembled back as easily.


Yours is the one with ballsy uning gear , a cool thing and easy to clean and does not break, unlike those otger ones (although does not afford as fine a tuning as some others due to small mechanical advantage but so frikkin' what...)

[kiwi_steve]

Nice job derusting, what did you use?

Just some cheap rust killer - Phosphoric acid based - I've been very pleased with how its worked.  Everything I've used it on has come out really nice but I've been very careful to fully wash down everything and keep an eye on how long it soaks for.  The chassis I left outside and brushed liberal coats on (I had nothing big enough to soak it in, and nowhere near enough anyway) keeping it wet for about 3-4 hours... it worked really well.  You can't (to the best of my knowledge) get Naval Jelly here.  As you can see it did a nice job on the dial lamp holder, which was very rusty and tarnished to begin with.

[Image: http://i241.photobucket.com/albums/ff222...qb38rm.jpg]

As for caps, other than usually not taking apart padders/trimmers part, they come apart very easily and are assembled back as easily.

This made me chuckle - the darn thing soaked up about 2 hours of my time in reassembly.  As you can see from the photos below, without removing the rivet holding the grounding tabs in place (and I couldn't remove it as I had nothing small enough to replace them without rubbing on the vanes) I had to bed them well beyond what I thought they would take... but they took it.  I think next time I'll see about buying some evaporust or getting a sonic cleaner.  The main time putting it back together was getting all the vanes neatly aligned which took ages, and then having to do it again because I realised when it was done that I hadn't tightened the ball bearing cap at the back that seats the main shaft - which pushed all the vanes together so I had to start again!   Once derusted I clear coated it to hopefully stop it re-rusting.
[Image: http://i241.photobucket.com/albums/ff222...xjxqwd.jpg]

[Image: http://i241.photobucket.com/albums/ff222...nyq44m.jpg]

Yours is the one with ballsy uning gear ,  a cool thing and easy to clean and does not break, unlike those otger ones (although does not afford as fine a tuning as some others due to small mechanical advantage but so frikkin' what...)

I didn't realise they came with a geared tuning gang... although I seem to recall the later runs did change part number... but simple is often best, so given the grief this one has caused I doubt I want to put anything else in it

Cheers

Steve

[kiwi_steve]

The power transformer checked out ok... I rewired it using the RMA scheme before I found the original Philco colour scheme on a service bulletin (there was no easy way to tell the original colours)... so I rewired it again

Before
[Image: http://i241.photobucket.com/albums/ff222...d71hew.jpg]

[img][URL=http://s241.photobucket.com/user/4wdstuff/media/Philco%2089B%20Code%20123/Philco%2089B%2046_zpsl21cnade.jpg.html][/img]

[Image: http://i241.photobucket.com/albums/ff222...1cnade.jpg]

After
[Image: http://i241.photobucket.com/albums/ff222...u14vwo.jpg]

And then AFTER after
[Image: http://i241.photobucket.com/albums/ff222...a0uuyc.jpg]

[morzh]

I coud be mistaken about the gear, I saw the balls lying there and I thought that was it, it usually involves the bell shaped thing pyt over the shaft with bals in them.
Maybe not here.

[kiwi_steve]

I coud be mistaken about the gear, I saw the balls lying there and I thought that was it, it usually involves the bell shaped thing pyt over the shaft with bals in them.
Maybe not here.

That sounds way too fancy for my radio

[kiwi_steve]

One thing I did before reassembly was to bake the coils.  I left them sitting by a 75W light bulb for a couple of days... then I gave them a liberal coating of clear polyurethane spray to try and stabilise their sponge-like behaviour  I think the Osc coil enjoyed it - you can see it smiling.

[Image: http://i241.photobucket.com/albums/ff222...fatqtm.jpg]


And the dial was a mess, but intact.  I cleaned it with IPA and then rubbed a light film of 3-in-1 oil over both sides which has made it look fantastic.  I don't know how long it will last, but its great for the time being

Before:

[Image: http://i241.photobucket.com/albums/ff222...7fjdtl.jpg]


After:

[Image: http://i241.photobucket.com/albums/ff222...llmdhy.jpg]


And here are some of the notes I took during disassembly which were supposed to help putting it back together 

[Image: http://i241.photobucket.com/albums/ff222...lmwyqj.jpg]

[sam]

steve
looking great

[kiwi_steve]

Long story short, its almost ready to fly There are a few other rebuild details I'm sure I'll get to - but I'm almost finished underneath and then its flip and finish The end is nigh... its been 6 months or so, will be nice to finish the chassis and get on to the cabinet (an area I have absolutely no skill in at all)...

[Image: http://i241.photobucket.com/albums/ff222...6tdmnx.jpg]


And there is one missing purple line here... anyone spot where it is?
[Image: http://i241.photobucket.com/albums/ff222...xkfd1f.jpg]

Cheers

Steve