[Kurt P]

Getting started on my first Philco here, done some research and hopefully I now know enough to be dangerous. 

Overall it's in pretty good shape but it's missing a few things, most notably a speaker and output transformer.  If anyone has a speaker and OT that will work (I understand it's the same speaker in a 19, 43 and 71) please let me know!

   

Not a lot of rust, either...

   

Not too much has changed but there are a couple of whacky things in here...

   

Looks like this cap was just tacked in, not sure if the old one is still in circuit but this is an easy fix...

   

I think this is supposed to be the 2nd IF transformer.  Heh, looks like this was pulled from a 40s AA5, definitely doesn't match the other 89s layouts that I've seen online...

   

I followed the guide to removing the caps from the tar bakelite boxes and it was incredibly easy!  I did 2 in around 20 minutes, way better than some of the horror shows I've seen on youtube.  Sure they were the easiest two blocks to get to but I didn't have to unsolder any wires but it looks like these aren't going to be a hurdle after all.  Replaced parts 36 and 17...

   
   

Hopefully I'm on the right track with the other blocks:

Part 23 & 24 are the same value and both go to ground.
Part 26 just has one cap in it, the center is a tie off point.
Part 41 just has one cap in it, the center is a tie off point.

Part 9 is a little less simple with a .0015 and a .05 cap with this strange note: "The .05 mf. section connects the same as condenser 6."  Can anyone translate this for me?  I see that Part 9 is the .0015 cap in parallel with an 8K resistor to ground so that's pin 2 to 1, should the .0015 cap go from pin 3 to 1?  Seems like the only option, are they trying to say that this cap also goes to ground like condenser 6?  It's possible I'm overthinking this, just want to be sure.

Part 4 looks pretty simple since the wires are color coded.

The power transformer checks out OK, so does the oscillator coil.  Unfortunately the detector/RF coil has an open primary.  I've found good instructions on rewinding this coil elsewhere on the phorum so hopefully it'll go smoothly.

I'll probably use 2 watt resistors for the ones that are out of spec.  I don't see any ratings on the resistors in the parts list.  Resistors 18 and 30 are a little bigger, but maybe that's what 2 watt resistors looked like in the 30s!

I'll look for rubber parts, grill cloth, correct speaker mounting screws and other bits and bobs down the road.  Appreciate any insight from people who have tackled one of these before and thanks for this great resource.  Glad to be here!

Kurt.

[radiorich]

Hello Kurt,
Welcome aboard and you have a nice set to start on !

Yes, the bakelite blocks and I too find them fairly easy to do .
I have been working on a Philco off and on in between other projects .

Sincerely Richard

[MrFixr55]

Hi Kurt
Welcome to the Philco Phorum. Lots of phriendly pholks (see a pattern here?) who are happy to help.  Keep posting on your progress and keep asking questions.

I had commented recently on 2 different Pholks that have acquired Model 89s.  Yours is the third.  I may be having an experience of deja vu, but my last post involved a guy named Curt or Kurt, also with an 89 missing a speaker. OOh, it's you!  A Moderator may combine your threads, as this is the same radio with new info.

Congrats on the work you have done so far.  It seems that thank goodness, you are starting with a clean chassis.  However, I think that that IF can mounted on the rear of the chassis was someone's "Mod", as it is a chronologically later design than used by Philco at the time of manufacture of your radio.  It looks dangerously close to tube socket connections.  It also seems that the filter caps were replaced before but may be old enough to want to replace again, especially the blue one under the chassis.

From my previous posts, you will find that this is similar to transformer powered AA5s except for the existence of an RF stage (AA6?) and the troublesome "autodyne" oscillator-mixer as opposed to the "pentagrid convertor" introduced (by RCA?) the same time that this set was designed.  Philco used the autodyne oscillator mixer in other models, including the model 80, but the circuit design of the 89 is a little more troublesome.  They switched to the 6A7 Pentagrid detector on new designs, but on some sets (such as the successors to the 80Jr.), they stayed with the autodyne circuit.

My notes on another 89 are linked below.

Help understanding a 89 radio rebuild new guy (philcoradio.com)

The correct speaker is a K7 style 8" speaker, Philco P/N 02819, also used on table versions of Models 19, 43 and 71.  Field Coil impedance is 1100 Ohm.  If you can't find the correct speaker, you can use any 8" speaker with a field coil of about 1100 Ohm or a PM speaker and 1100 Ohm resistor.  Any output  transformer that was used with a single 41, 42, 2A5, 6F6 or 6K6 output tube and matches the voice coil impedance of the desired speaker can be used.  Primary impedance should be about 7K Ohm.

RE parts 8,9 and 6, they should all be in the same block.   One end of caps 6 and 9 and one end of resistor 8 should be connected to ground through the end terminal if this block with the ring terminal integrated to it.  Make sure that good clean uncorroded star washers are in place on this terminal. when remounting the block.  Cap 6 is a 0.05uF B+ bypass cap, whose other end connects to the middle pin of the block.  A 0.047uf cap will suffice here.  Resistor 8 and cap 9 are paralleled and are in series with the oscillator tickler coil and supply cathode bias.  These parts connect to the remaining end terminal.  Please note that there were many upgrades to this circuit and the current values are 8KOhm for resistor 8 and 1500pF (0.00015uF) for Cap 9.  Best to use 2 700pF Mica caps here.  Please note that to confuse things more, the numbering convention in the diagram posted in the Philco Library is different from that of the Nostalgia Air diagram. This is because these are different Code numbers using different tubes for the 1st detector.  Please ensure that your set uses the '77 1st detector (autodyne oscillator-mixer) tube as the numbering and values for sets using the '36 1st detector are different. Please also note that the '77 1st detector is more stable than the earlier '36 detector.

There are articles in the Philco Library (part of this Phorum) that describe all of the changes in the various versions of the 89.  The Nostalgia Air diagram lists several modifications to the original circuit having to do with insulators for trimmer caps and a revised tuning cap.  My guess is that your radio, having the later '77 1st detector, has the mods described in the Nostalgia Air document 

The Philco Library document "evolution for the Model 89 is linked below:
Evolution of Philco Model 89 – Philco Library (philcoradio.com)

If you can connect a speaker, you can still test the set even with the dead RF to 1st detector coil primary.  Just touch a 10-20 ft wire to the grid cap of the 1st detector.  If you can pick up a station, then the 1st detector appears to be working.  This is a very good sign.  Note that because of the low IF frequency, it is likely that you will pick up a strong station on more than one location on the dial.

So in summation:

• I think that you have a later version of the Code 123, that uses a '77 detector.  If so, this is a bonus, as the '77 1st detector is much more stable than the '36 1st detector, and other service and factory mods are likely completed.
  
• If you can't find the right speaker, use any 8" speaker with an output transformer with a 7KOhm primary and secondary that matches the speaker voice coil impedance.  The field coil should be about 1.1KOhm. If using a PM speaker, use a 1.1K resistor and upsize Caps 44 and 46 to at least 20 uF
  
• Resistor 8 and Caps 6 and 9 are in the same block.  One end of all 3 components connects to the end lug that is grounded.  The other end of cap 6 (0.05uF) goes to the middle lug.  The other ends of the 1400pF cap 9 and 8KOhm resistor 8 go to the remaining terminal.
  
• The IF Can that likely hides a coil is likely an add-on.  Make sure that it does not short to tube sockets if left in.
  

Hope this all helps!