[Greg Hyduke]

Hi all,

51-yr-old newbie and total amateur here...

I have just returned my attention to a Philco 91B single-band that was my maternal grandparents' first radio. I have had it as a decorative antique piece since 1976. At the time I was 16 yrs old and I rescued it from my dad's garage. It had been his workshop radio and he had painted it, of all things, navy gray. I loved the gothic cathedral shape and the deco grille and the oldness of it. I re-finished it myself, by hand, which came out incredibly gorgeous, but never did try to get it working again. Later when I got married we bought an old Vic and it's been a decorative antique in my house since then. Over time the grille cloth started deteriorating badly. When it got so shabby that the the speaker cone and pot became visible, I moved it into my workshop down the basement thinking I would try to do something with it 'some day'. That was ten or so years ago.

Yesterday I started looking at it and doing some research with an earnestness I had never done before.

If I'm interpreting the chassis layout for a 91B Code 121 (same as 14/121) that I found on the linked Philco Repair Bench site correctly, it looks to me like two tubes may be missing. There are supposed to be 9, right? I count 7. The two that are missing are the back or innermost pair of the set of four tubes to the right when I am looking into the back of the set. (The 42 and 80 that sit behind the 37 and 42 respectively?) There is a flat piece of metal forming a small barrier. Behind the barrier is a space where it looks like the two tubes might should be. Behind that is the transformer. I never took any tubes out and I don't think my dad did either. Would it play with 7 instead of 9 tubes?

All 7 of the tubes light up, by the way. (I know, I wasn't supposed to do that, but I plugged it in before I found this site!)

Everything else (power transformer, tuning condenser, dial/shadowmeter works, etc) looks to still be there. The Bakelite escutcheon still looks great. The rosette knobs are fine. The cabinet is superb except for a sliver of veneer lifting off the rim at the very bottom near the moulding, facing the back.

Options are: (A) at a minimum, figure out how to replace the grille cloth with a repro myself, or have it replaced by a professional, so at least I can display it as an antique piece again; (B) send it off to a professional and have the grille cloth replaced AND get it working again, or © sell it.

My issue - and the reason I have come here - is that I have no idea in even rough orders of magnitude terms how much A or B will cost.

I know this probably sounds naiive and also maybe dispassionate on an enthusiasts' site like this, but from my perspective, I can't afford to get into this as a project without knowing what the total cost is likely going to be at the end, and I don't have the expertise to make my own estimate. A couple hundred I can do. A thousand I can't. But see, I don't even know if it's worth sinking a couple hundred or a thousand into it!

I have lots of photos I could post, including close-ups of the grille/speaker cone opening and the components, if that would help. (And, if I can figure out how to post them...)

I am at your mercy and would appreciate any advice I can get.

respectfully,
Greg

(Sorry this is so long...)

[Greg Hyduke]

Okay, I am going to attempt to post pertinent photos...

[Image: http://i1223.photobucket.com/albums/dd52...1324236398]

[Image: http://i1223.photobucket.com/albums/dd52...1324236669]

[Image: http://i1223.photobucket.com/albums/dd52...1324236980]

[Image: http://i1223.photobucket.com/albums/dd52...1324236753]

[Image: http://i1223.photobucket.com/albums/dd52...1324236722]

[Image: http://i1223.photobucket.com/albums/dd52...1324236834]

[Image: http://i1223.photobucket.com/albums/dd52...1324237104]

[Image: http://i1223.photobucket.com/albums/dd52...1324237023]

[Image: http://i1223.photobucket.com/albums/dd52...1324237060]

[Phlogiston]

If the 80 is missing (4 pins on bottom of tube) the good news is that you probably did not hurt anything turning it on. The bad news is - it will not work with the 80 missing it is the rectifier for the high voltage - no high voltage - no work. If there are 2 42s in push pull it will work with one missing.

Where are you located?

[Greg Hyduke]

I'm at the Jersey Shore, phlogiston.

If there are 2 42s in push pull it will work with one missing.

According to the diagram on the Philco Repair Bench site there are supposed to be two (2) 42's, cattycorner to each other in a set of four tubes to the right. There is only one 42 in my set, the one to the right of the 37 in the pair of tubes closest to the opening in the back. (Is that what 'push pull' means?)

Just before I replied to you I submitted a post with some photo links, including the chassis, so hopefully it will be posted. EDIT: It was posted above, but I've also posted a link to the slide show below, with larger photos.

[codefox1]

Actually you are lucky that the 80 rectifier is missing, as you will certainluy have to replace the electrolytic capacitors at a bare minimum before firing the set up again. Actually there are about a dozen or so other capacitors that should be changed out as well along with out of spec resistors. You will need to get a nice little digital volt-ohm meter (<$20) and a circuit diagram for your set.

None of this is rocket science, or large expense at all, and if you have a little time and interest, we can help you through a restoration. Don't plug it in again so soon.

[Greg Hyduke]

Thanks, codefox. If it doesn't cost me more than a couple hundred bucks, I think I might like to try. Should I buy a book? (I see that the site-owner has one...) Or does the site have all the schematics and step-by-step instructions and part sources I would need? Remember, I really have no idea what I'm doing or even looking at.

Not sure why those photos above are so small, but here is a link to the Photobucket site where I uploaded them:
http://s1223.photobucket.com/albums/dd52...l%20Radio/

The parts and wiring to the dial/shadowmeter (slide 11) looks intimidating.

See slide 13? That's a photo of tube 37 and 42. There's a rusty metal barrier behind them. Just behind that is a space. And behind the space is the transformer. Is that space where the 42 and 80 are supposed to be? (I've seen a picture of a Model 91B that didn't have that thin metal barrier. That's confusing me...)

I'd also like someone to take a close look at slide 6, the close-up of the shredded opening in the grille and the speaker cone. Is that the speaker material that is shredded too?

Also, I've seen pictures of sets here with the chassis out of the cabinet. That would seem practical for working on it, but how do you remove the chassis from the cabinet?

[Phlogiston]

Schematic

http://www.nostalgiaair.org/Resources/657/M0029657.htm

The good news

The cabinet looks nice. The pictures are still small, but you might not NEED to do anything to it except replace the grill cloth.

It looks like it might have a couple of globe tubes, always a plus. If all of the tubes you have are good you should be able to get the missing 2 for around $25.

It still has the original Mershon (copper) caps. Also a big Plus. Most of these were replaced and thrown away. This is also a minus since there is just about a 100% chance that they are bad. So don't plug it in again!

This is a family heirloom and you have the interest in keeping it and the ability to make a small investment.

The bad

This is your first radio. Please do not electrocute yourself. You do not have to look hard to find 300 volts on that chassis when turned on. If you have any doubts find a local repairman that specializes in OLD radios. That is why I asked where you are. Others here may suggest someone. A $200 RESTORATION would be cheap. A $1000 repair would be WAY too much.

As mentioned the caps will short the power supply when you find an 80 and install it. ALSO, that radio has line filter caps across the 120Volt AC line even when the switch is OFF. These are also very likely to short and may cause a shock or fire. Again, do not even plug it in.

The chassis is rusty. The shields are VERY rusty. If the rust has not invaded the chassis too much it can be cleaned and touched up. Some people paint them. That usually means that they are too far gone, unless they were painted from the factory. If only the shields are rusty they can be removed and cleaned up or replaced, which is also a consideration for the entire chassis. Sometimes a nice one, less a cabinet becomes available. Occasionally it has even been rebuilt.

You need a speaker or at least a new cone.

The rust on the chassis causes me some concern for the cabinet integrity since moisture also causes the wood to delaminate and joints to fail. But this should be easy for you to check.


You might still be able to get an acceptable grill cloth from these guys:

http://www.tubesandmore.com/

Pattern:
S-G431F

Don't wait long to order.

If you elect to sell it, I would be interested in the cabinet.

Good Luck

[Greg Hyduke]

Thanks so much for all that information, ph, and I appreciate your frank assessment.

I hope this link will let people see the photos in full size slide show mode: (I've never used photobucket before.)
http://s1223.photobucket.com/albums/dd52...=slideshow

If there's another better way to let people see the full size photos here, someone please advise: They're all 2048x1356 jpgs. Should I just attach each one? I feel like I'm inside the cabinet the zoom and detail are so good. (I wish I had photos like this that were labeled, especially when I'm looking at the back of the dial and shadowmeter and speaker.)

I'm struggling to understand where the parts you and codefox are referring to (capacitors, resistors, shields, etc) are even located on the chassis, so I definitely need to get a book or some picture of the chassis on-line that has each and every part labeled.

The schematic helped me understand what each of these tubes are for, and now I understand what you meant about only needing one (1) 42 to power it up. And it shows the speaker wiring. But unless I'm missing it, it doesn't identify and show the location of anything else except the tubes.

You mentioned globe tubes. Based on that being descriptive of the shape, it looks like the 37's (DET RECT, DET AMP, and AF) and the 42 (PWR) are all globe tubes. The 44's (RF, IF) and 36 (D. OSC) are not. Is that correct?

Why does the 37 DET AMP have a casing around it? Is this one of the shields you were referring to? Are the other shields missing or is there something peculiar/special about the DET AMP that it requires a shield?

Is the thin metal wall or barrier between the 37 AF and 42 PWR and the missing 42 PWR and 80 RECT also considered a shield?

Similarly, is the curving open box-like thing covering the 44's and the 36 a shield?

Are the Mershon copper capacitors the two canisters immediately to the right of the 37 DET AMP with six holes in a circular pattern in the top of each?

Are the silver canisters the other capacitors? I count 5 of those. Two that look to be the same exact same shape and size to which the 44 RF and the 36 D OSC are wired through a hole in the top that is not dead center. Another one next to those in a row that is the same exact shape and size that is not wired to anything and does not have a hole in the top. And a fourth in that row that is thinner in diameter and shorter that has a hole in the top dead center but not wired to anything. The fifth is smaller than any of those and it's tucked in next to the 44 IF, to which it is wired.

I am guessing that the tiny upright bulb is a light for the shadowmeter. (By the way, I am assuming the reason the dial looks a little low to me when looking at it from the front, through the escutcheon, is because the yellow-y ~3/4 round tuning disk (dial?) with the frequency numbers and graduated marks is warped a little around the edge. If it was in its original shape it would sit closer to the slot in the escutcheon, and therefore appear higher when looking at it from the front. Is my assumption on that correct?)

What is the other bulb? (Appears to be blue or have something blue inside it.)

Where is all the wiring? Under the chassis?

The rust on the chassis and shields (if I am guessing right on what those are) is removable, I think, with baking soda, maybe one of the less harsh solvents, steel wool and elbow grease. The rust I am more intuitively concerned about is the rust on the ribbing of the tuning condenser. Is that bad? Can I go at that rust like the rust on the shields? Or do I need to leave the condenser alone?

The cabinet is structurally sound. It's very solid. I detect no soft spots and see no separations anywhere. When I move it, I carry it around with one hand by the arched spanner at the top of the back.

Thanks for the grille cloth link and pattern number. I found a site called Retro-Tronics that sells a laser cut grille cloth frame (fiberboard) for $20. Do I need to do that from the back? Do I have to remove the chassis and take the speaker cone etc off from inside? Do I just unscrew the two screws I see in the face of the grille? I am fairly confident I can replace the grille cloth if I can figure out how to get to it from the back. That would let me put off the question of restoring it to working condition.

My biggest concern about a restoration is whether or not I can do it myself. The schematic is intimidating and I am trying to reconcile your comments (which are a little more cautious) with codefox's. There's a big difference between "not rocket science" and "if you have any doubts." I have ALOT of doubts. You said that I may not NEED to do anything other than replace the grille cloth (by which I am assuming you were referring to getting it working again), but I don't know how to make that assessment. Replace all the capacitors and resistors and then plug it in again to see if it works?

Finally, some questions from a collectible standpoint: I collect WWII militaria, where originality is prized. Take Willys Jeeps for example, which I own. There are all kinds of reproduction parts available to restore one. But original parts are more desirable and make the Jeep worth more in value. Does it work that way for Philcos? Do serious restorers try to restore as much originality as possible? I don't know that I want to even treat this Model 91B that way; as you say, it's an heirloom, and let's face it, my renewed interest is sudden. But given that it's in fairly good condition and has remained almost completely untouched inside for 79 years, I wouldn't want to do anything stupid that ruined its integrity either, if it matters. (Is the 91B Baby Grand coveted? How rare is it? I am of the unschooled notion they are not common, but not necessarily scarce either.)

[Phlogiston]

All very good questions, which will lead to many more very good questions.

Don't take this the wrong way, but you are starting at a very basic level. The decision that you have to make is whether you want to take the time to do this safely and correctly, many people do and enjoy it, OR pay someone else to do it. If you take the time to learn how it will probably lead to many more radios.

That being said, if you want to do it, you need to find a good book - or two which will cover basic TUBE electronics and old radio restoration. For me to give you all the information that you NEED would simply take pages and pages of text pictures and drawings.

You will also find much good and bad information on the internet.

I would encourage you to read up a little and then ask questions pertaining to your radio here.

As to your radio's value and scarcity, it is a classic easily identified by the public as an "antique" radio. Its value at this time is for parts or restoration, I would say around $100 tubes and all. If that cabinet is as good as it looks and displays nicely and the radio chassis is restored correctly and works well, it could sell for $400 or more in the right venue. Keep in mind that the old radio market is depressed except for the very most desirable sets. This might change if the economy picks up and it might not. It would be better to look at this as an investment in your family's history and a nice hobby rather than a road to profit.

[Greg Hyduke]

Thanks. Apologies to you and all for the basicness of the questions - trying to quickly assess the set and just how big my learning curve is, admittedly, by using this forum and any gracious expertise I might find here, as a shortcut. If I took on the project I wouldn't continue like this.

My question about rareness wasn't about salable worth so much as value in a preservation sense. Usually (at least in WWII militaria) there is a correlation between scarcity, desireability, and value. If this was one of the "more desireable" (as you put it) Philco sets, I was thinking I might approach what to do with it differently. It's obviously not a museum quality example of a Model 91B, but it seems like it could be if I wanted to invest that kind of a restoration in it, given the condition of the cabinet and the fact that everything in it is original. Some WWII-era Jeeps, to extend the analogy, will never be museum quality, because they are fundamentally altered, cannibalized, or fixed with parts that were not original in 1941-1945 and in ways that can't be undone. Butchered, in a word, by what we more appraising and careful collectors and restorers refer to as "Bubbas." I didn't want to be a Philco Bubba, especially if this was a rare set.

My take on what you're saying is, if I was only interested in having this set restored, I should probably pay to have it done, because it's not going to cost me more than a couple hundred, and it will otensibly be done professionally and correctly without any costly or ugly or unsafe mistakes. If I want this restored AND I wanted to do it myself, as a pleasure, I should probably expect to invest alot of time and learning in addition to money.

I don't know that I can handle another demanding "hobby" right now, and I'm afraid that if I say I'll take it slow, a little at a time, it'll be another 10 years.

I think I'll see if I can replace the grille board and cloth for now.

Thanks, again. I really appreciate your guidance, helpfulness and patience.

[codefox1]

Really isn't as hard as it looks. I didn't even look at a radio for decades, and just fell in to it again a few years ago.

Safety first. The radio can and will kill you if you let it. Best never have your hands on any of it when plugged in. You can buy meters for a couple of dollars that can do testing for you, and if they don't make it. not a big problem. Teach yourself how to solder if you have forgotten or never knew. 99% can be done with a pencil iron of 25 or 30 watts.

If you can get a schematic, which is really a lot like a blueprint, you can get a sense of what is going on in the set. All capacitors need to be replaced in my opinion, along with all the small wattage resistors, which you will uproot anyway, and they are all just pennies apiece. Take lots of pictures, proceed methodically, and resign yourself to maybe a couple of months before everything is correct. Never give up.

Always someone around here who isn't to busy to chat.

[Greg Hyduke]

phlogiston posted a link to a 91B schematic above. I already downloaded it. I'd have to bone up on wiring diagrams just to be able to read it. What I'm looking for, for now, is a spatial diagram or layout or drawing or labeled photograph of a chassis so I can identify what and where everything is located. The schematic doesn't really do that (except for the tubes, shown and labeled as they are arrayed on the chassis in a little drawing on the bottom of the schematic). For example, when you say I will uproot the low-wattage resistors, I find myself wondering where they are and what I will be doing and at what step in the process that uproots them. Pulling on someting, I am guessing, probably a wire. Heh.

I am off to the library... Too many questions, and I see that this place is really for the more experienced. That's totally understandable. I still don't even know if I'm supposed to take the chassis out of the cabinet, and if so, how. So if I'm going to do this (still an if) I feel like I'm a long way from a voltage meter...

Thanks again.

[Ron Ramirez]

Greg

Everyone is welcome here at the Philco Phorum, whether they are an experienced collector/restorer or a "newbie."

I suggest you take a look at this page here in the Phorum:
http://www.philcoradio.com/phorum/showth...?tid=14958

and then look at the pages intended for beginners at Phil Nelson's website:
http://www.antiqueradio.org/begin.htm

The original Philco service literature includes a drawing of the underneath of the 91 chassis showing where the various parts are located. You can obtain this service information, at a reasonable cost, from Chuck Schwark at the Philco Repair Bench website.
http://www.philcorepairbench.com/schematics.htm

There are plenty of folks here willing to help you. Terry (Radioroslyn) is sort of our unofficial official resident technician, and I am sure he will chime in with help if you ask. Many other folks here will also offer help and advice, and some have done so already.

Oh, and to answer your question about the chassis - yes, it must be removed for service. Not too difficult - remove the four knobs, they should pull off although sometimes they become stuck from decades of corrosion. If you find you have a stuck knob, just ask and someone will offer some suggestions on removing it.

Once the knobs are off, there are four bolts under the radio that hold the chassis inside the cabinet. Remove these bolts, and the chassis will slide out from the back. You will have to remove the speaker at the same time since it is hardwired to the chassis (no connector plug & jack as used on some Philco models). The speaker is held with four nuts in back.

Good luck, and have fun! Yes, you can learn how to service it yourself, if you are patient, willing to learn, and do not take any shortcuts.

[Ron Ramirez]

One more thing. Directions for posting photos using Photobucket may be found here:

http://www.philcoradio.com/phorum/showth...p?tid=4371

Please, do not post images larger than 1024 pixels wide. Thanks.

[Greg Hyduke]

Thanks for the links and the advice, Ron.

Didn't mean to imply the site was exclusive or unhelpful - everyone has been very gracious. I just have to do more reading before I ask so many basic questions. I appreciate your tips on removing the chassis. I may do that tonight just to set things up for replacing the grille board and cloth, to learn where everything is, and to try to remove some of the rust. I think I'll delay my decision on whether to DIY it or send it out until I read more...