Philly BOL Schematic

[Robert Feenstra]

What schematic best represents the BOL Philharmonic?  The schematics I find seem to be for the pointer dial.  How much difference is there?

Also, my BOL has had roughly half of the capacitor changed using mostly Solar brand.  I presume this was done quite some time ago and was wondering how good these capacitor were/are.  The radio works and is quite sensitive, but there are quite a few problems so I'm thinking of recaping the whole thing.  I wish I had all of the originals so that I could restuff them!

[Kent King]

I have added a diagram (split across two files) to the Info Archive - it gives the later Riders schematic that is closer to the Deluxe Philly. I'll try to get a clearer scan and upload it this weekend. I didn't realize I only had the 1937 diagram out there. If I could ever retire, I'd have time to review all the set folders for more info. I have a ton of material that is not even scanned in yet. 

Regarding caps - I save every cap for restuffing for special sets. I can spare some extras I have but I doubt I'll have enough to do an entire Philly. Let me know if you want to get some from me. I'm sure glad you picked up those sets, they are in good hands - I was afraid someone would break them up to put on ebay as components.

Kent

[Robert Feenstra]

Thanks Kent!  Yes I would be interested in what caps you can spare. I can PM you info.  The schematic would be great.  I have all of the Riders but it seems to go from the ppointer dial to the AM/FM.  Not sure what's in between. The Riders schematic I have is 14-43,44,  dated April 4 1939.  The pics of the chassis do not correspond to the BOL I have.

[mike hadley]

Rob;

Have you considered rolling your own cap tubes, I have found that brown parcel paper looks good, as long as you seal the paper before applying white glue and rolling the tube, hairspray is excellent for this, it stops the tube from absorbing too much wax when they are dipped.

[Kent King]

The FM Philly is just the BOL Deluxe with FM added, it will probably be the closest diagram we can locate. However, I will try to find as many of the Philly diagrams as I can and get them posted soon.

Kent

Robert Feenstra said:

Thanks Kent!  Yes I would be interested in what caps you can spare. I can PM you info.  The schematic would be great.  I have all of the Riders but it seems to go from the ppointer dial to the AM/FM.  Not sure what's in between. The Riders schematic I have is 14-43,44,  dated April 4 1939.  The pics of the chassis do not correspond to the BOL I have.

[Robert Feenstra]

Mike, yes I have!  But, it's a lot less time consuming to re-stuff.  I have info on a guy who made all new cap tubes for a Masterpiece VI.  Certainly a possibility.

[Scott Seickel]

Robert, which BOL are we speaking of?  Pretty sure I sent you the AM/FM schematic I redrew?  I personally acknowledge 3 versions of the BOL, that being the earliest 7 knob, then the 9 knob then the AM/FM.  All 3 have significant changes. 

[Scott Seickel]

Oh, and BTW, those Solar caps are almost certainly original.  The Solar Sealdtite (blue color) are correct for the period.  Many of these later Philharmonics used several different brands in the same chassis, presumably, whatever Scott could get their hands on for a reasonable price.  I have several Philharmonics that have those Solar capacitors, and they are original. 

[Robert Feenstra]

Thanks Scott.  This BOL is NOT the AM-FM.  That one is still in the re-chrome process.

This BOL follows the Philly schematic (pointer dial) in the archives fairly closely with several variations (eg. the treble control is wired as it is in the AM/FM).  The blue Solars are definitely a later addition as the solder connections indicate they have been changed.  Pieces of the original capacitor wire are still in the terminal with the Solar capacitor wire wrapped around the connector.  Most are measuring ok but one in the Expander push pull 6L7 grid circuit was leaking giving a bias on the grid a nearly 0 volt reading.  That makes them all suspect in my mind.

If you have a Schematic of the 9 knob Philly BOL, I would be interested!!!!

Question on the Expander:  The expander full on has very little effect.  The output of the 6J5 driver is about 3-4 volts AC as measured using a scope on the coupling capacitor to the 6H6 diode.  But the voltage output from the diode circuit feeding the control grids on the 6L7's varies by only a few tenths of a volt - not enough to give a noticeable volume variation and almost no indication on the eye.  The 6H6 test good and I have substituted a NOS 6J5 for the driver..  Any ideas?  I haven't set the controls using the recommended procedure, but have played extensively with them to no good effect.  In general, I don't like the effect of the expander on other radios, but want it to work correctly.  Thanks in advance for anyone's help!

[Kent King]

Have you looked at the expander documentation in the Archive? Should be under accessories. The expander circuit is sensitive to component issues - I strongly recommended new capacitors throughout the circuit and check all resistors to spec too. 

Kent

[Robert Feenstra]

Thanks Kent.  The capacitors have been changed but the resistors have not.  They are "reasonable values".  But, I think I will change them anyway.  I'll look up the info in the Archive.

I have re-stuffed most of the original tubular caps.  I left the later Solar caps.  However, as I mentioned,  I did have one of those leaking so all are in question.  You mentioned that you might have some originals that I could stuff to replace those.  I sent a friend request so that I can PM you.

One more question:  The caps associated with the bass control chokes (.02 and .025 I believe) are molded and look like mica's.  But their values are higher than what one would expect a mica to be.  Are they paper as well?  The bass does not quite work the way I think it should.  Not nearly as good as on the pointer dial I have in the Gothic cabinet.

[mike hadley]

Hi Rob,

Yup the caps around the filter are paper as well, be careful with the values as the filter is resonant at 60hz.

[Robert Feenstra]

Thanks Mike.  I am aware of the 60 Hz issue.  Evidently, a lot of radio stations back then had a 60 Hz problem!  Those caps will be changed!  Getting to be a number of the not so lovely yellow caps in this radio.