The PHILCO Phorum

I am going through a 38-10.

My question is this; the tuner assembly looks as if it was isolated from the chassis with rubber feet. On this radio the rubber is rotten or missing on 2 of the 3 mounting points. This has caused the tuner to move around on the chassis.

1. Is the tuner suppose to be isolated or is the rubber a shock absorber type deal?

2. If it is there to isolate the tuner from the chassis electrically what would be a good substitute for the rubber?

Daniel

Also,

The unit is missing the speaker and output transformer. Until I find a suitable replacement I was thinking about using something off the shelf. Can anyone recommend a replacement speaker and where to get one? I figure a cheap output transformer from Antique Electric Supply will wire right up after looking at the schematic. Any suggestions.

Daniel

Hi Daniel,

I've just finished electrically restoring my 38-10 - working on the cabinet now. Here's what I know:

1. It's a shock absorber. If you check the schematic, you'll see that one side is grounded. There's a flexible, braided copper wire connecting the capacitor frame to the chassis.

2. It's not, but having a single ground point might affect the circuit behavior. Also having them will improve oscillator stability and keep the assembly in the correct position so it's centered in the cabinet hole. Although I have all 3 feet, they are a bit rotted so I'm looking for suggestions too Here's what mine look like.



Here's a bunch more on my Flickr site: http://www.flickr.com/photos/70039806@N0...383644064/

- Bob

an easy-fix for replacing the old rubber tuning cap grommets can be found at your local hdwe stores. Use the neoprene old-style rubber faucet washers. The center hole in the rubber washers can be carefully drilled-out with a small drillbit. The new faucet washers are avail in flat & tapered designs in several o.d. styles diameters & thicknesses. You can "stack" them, cut them with a knife ( carefully) for proper heights, special designs,thicknesses,etc you need, trim off excess outside measurements if needed, and fit them together, or separately !Careful use with a exacto knife can peel, or shim the rubber to exact retrofits. Just be careful using the knife!! The rubber faucet washers work great for securing the tuning-condensers back to the chassis,( or tuning condenser frame assy) and no more gum-rubber future failures due to age. Neoprene lasts!!.. and since replacing tuning condenser grommets isnt exactly a "fun" project from the get-go, use neoprene, and be done with it ! Lowes has a good selection of all types & sizes rubber faucet washers in the plumbing dept!!Ive used them many times and works great when total-originality isnt an issue.Paying close attention to exact height needed for correct view of the cabinets tuning-window can be acheived by close inspection with the chassis sitting on cabinet-floor and taking measurements of the space between chassis & tuning condenser when tuning window view of dial-scales are leveled precisely.Then, you can cut & retrofit to your needs. If flat metal- washers were used, put them back over the new grommets same locations between tuning-condenser legs, and/or under chassis, or etc. Bingo! Nice secure tuning condenser that grommets replacements will last virtually forever, and no future heat induced rubber-rot.

Just what I was looking for. Thanks for the help, now I am off to Home Depot for the needed parts.

Anything on a Temp Speaker Audio Transformer set up until I can find an original?

Daniel

If you are looking for exact replacement grommets, you can probably get them here. http://www.renovatedradios.com/parts.html

Best regards,

Ed

Thanks, Ed. Renovated Radio does make great reproduction chassis corner mounts for the 38-10. Unfortunately, the 38-10 doesn't use grommets or washers for the capacitor mounts. They are more like sleeves that slide over the capacitor frame in 3 spots. You can see two of them in the picture I posted earlier. They are the black, rectangular blocks . I'm thinking of just wrapping some rubber bands around them for now.

- Bob

Cool pictures, I am waiting on some caps and a replacement dial from radio daze. I will get some pictures up tomorrow.

Daniel

Hi Bob,

Quote:Unfortunately, the 38-10 doesn't use grommets or washers for the capacitor mounts. They are more like sleeves that slide over the capacitor frame in 3 spots.

If you have one good sleeve, Ed (Blacksmith) of Renovated Radios will usually cast new ones for you just to get the mold, so he can add the piece to his product line. You might want to send him an email and ask about this. You would probably be doing everyone with the 38-xx tuners a favor, since they probably all need replacing.

Ed

Hi Daniel,

In regards to the speaker and output transformer you can substitute using a pm speaker but with some modifications. The speaker in your radio has a field coil. It is used to create a magnetic field around a pole piece for the voice coil to work against. It also is used in the power supply as a choke to help smooth the dc voltage. Here is the schematic. http://www.nostalgiaair.org/PagesByModel...013233.pdf Part number 44 the 1140 ohm field coil is what you need to replace. You can do this with a power resistor (About 15 watts is as low as I would go) close to the same resistance +/- 20%. Usually better to go higher in my opinion. You can order one from many different vendors. Mouser is a good place. The output transformer I would use for a 6F6 ( about 7500 Ohms) is the Hammond 125CSE from Radio Daze ( prices have gone up since I bought one!). You can use the 5000ohm tap or the 10000 ohm tap for 8 ohms if that is what your speaker is. I think either one will work and sound fine. This can be a permanent fix if you want and you can't find the original speaker. You can mount this under the chassis kind of away from the other components. It will get hot. Maybe some of the other folks can add some more insight.

Hope this helps
Terry

Thanks for all the great info. I am waiting for a couple of tubes right now and a new dial. I have already worked on the cabinet (It was in good shape except for the finish on the top was flaking away) I should have a working unit in a week or so.

Daniel

Hi Daniel,

That's great to hear. I think we're just about at the same point in our restorations! I just finished staining the top and sides of my cabinet.
How did you make out with that tuning capacitor? Does yours have the same black rubber mounts like in my picture?
I've contacted renovatedradios.com and am waiting to hear back if they are interested in reproducing this part.

Bob

Another new Question:

The large can as you can see in the picture has been replaced in the past. It originally tested ok on my Cap Checker but upon some testing after I recapped the unit it blew out. What would be the best way to replace it? Can you get these anymore?

it is suppose to be a 12MFD Can but this one has been replaced with a 16MFD 450v unit

Daniel

PS the green washers on the tuning assembly are only there for measurement purposes so I can build correct rubber mounts.

Note from site admin: Sorry, but the photo which was attached to this post is no longer available.

You can leave the orig electrolytic metal housing in place, then add a new cap in place of it under-chassis by adding a isolated terminal-strip. Did you actually "restuff" the orig electrolytic can that blew out? If not, you didnt complete your "re-cap" job from the get-go. Those old Aerovox filter caps either need to be re-stuffed, or, replaced with new caps mounted under the chassis before powering up the chassis. If you blew out a new-cap, ( properly installed with polarity observed), then check your schematic for other possible probs associated w / the B+ under chassis. Look for "shorts" from B+ to chassis ground (-) of your electrolytics.
Depending on the schematic,and circuit design, some 500v ratings orig filter-caps were used in the early sets for extra "surge" factor. Someone may have replaced a orig 500v filter can with a 450v can somewhere down the line yrs ago before you got your set? Ive run across similar circumstances before. Good luck restoring your Philco!

Hi guys,

Since my 38-10 is working so well, I really don't want to take the tuning assembly apart. So I took a cue from your green washers and just made some shims from rubber bands.



Works for me


Here's the radio all restored except for the speaker cloth. It's not too bad so I'll leave it for now.