[Tracy1928]

Hi. I need to know the number of Ohms this speaker requires so I can replace it with a modern speaker.
Thanks!

[Ron Ramirez]

The 91L is a 1932 model, not 1928.

Most 91 consoles used two speakers - a K-12 (8 inch diameter) and an H-7 (10-1/2 inch diameter).

K-12: 3275 ohm field coil, 1.25 ohm voice coil
H-7: 3275 ohm field coil, 1.25 ohm voice coil

The voice coils were connected in parallel.

[Tracy1928]

Hm the radio is a 1928 Philco but I got the 91 L model number from the visual id posts. Its currently in the shop getting cleaned and a new tube or I would take a look at the the label. Would model 75 make more sense? Thats the model number we used to find and purchase a new tube. The speaker is in bad shape. Does that make more sense? I'm sorry I can't access the radio today to read the label myself.
Thank you for your patience and help. Its appreciated.
Tracy

[Tracy1928]

Gads. Now that I look at them, the model number 75 was for the tube...ugh
I apologize.

[Ron Ramirez]

Well, since the 75 tube was not used in Philco sets until early 1933 (the models 89 and 19 were the first Philcos to utilize this tube), that means your radio is definitely not a 1928 model.

Can you post a picture of your radio? That will make it easy to make a definite, positive identification of it.

[Tracy1928]

I was thinking the same thing. Won't be able to for another day or two but will asap. The guy repairing it said model 75 for the tube so I guess we'll see what happens when the tube comes.
Thanks for your patience.
Tracy

[Tracy1928]

Well I finally got a look at my lovely Philco that's still at the shop. It is a Model 60L made in July of 1933. It has one speaker that is dead. What Ohms would a replacement speaker require?
Thank you so much for all of your patience. The replacement tube I bought works but think I need to replace the speaker to be sure if all other issues are resolved. Will post pics when I can.
Thanks again.
Tracy

[Radioroslyn]

What is the issue with the original speaker?? Your speaker has several parts to it some repairable and some not.
Terry

[Tracy1928]

The paper cone is completely deteriorated and has a hole in it.

[jerryhawthorne]

Tracy, if the cone is the only problem and the field coil and voice coil are good there are many people that replace cones.
Regards, Jerry

[Radioroslyn]

Ok so if you look at the speaker in the front in the center you should see a small nut. It holds a cardboard piece that looks like the insert you use in the center of a 45rpm record to reduce the large hole to a small one. That part is called the spider. The paper cone is glued to the spider.
On the back of the speaker there is a transformer that has four connections. Two of them connect to the back side of the spider. On the backside of the spider is the voice coil. The other two connections go to the wires feeding back into the radio chassis. On the speaker on the back in the center is the field coil. Where modern speakers have a large magnet your speaker has an electromagnet. One of the wires from the field coil will connect the transformer the other goes to the chassis radio.
The reason I explained this to you is if you would like to do a little troubleshooting we need to know the field coil is good. Sometimes they are open (no resistance) and is the death blow. Time to find a new one. But if it is good all you will need to do Is have it reconed. Up for some troubleshooting??
A couple of notes
When the set is plug in and turned on these wires on the back of the speaker carry about 300V of electricity. It is important that these wires are in good condition (no worn though insulation) cause if you touch them you will get the shock of your life!!! Don't ask me how I know!
Speaker replacement on this set isn't as easy as it is on a modern set because of the field coil. Modern ones don't one and your set won't play without it. Was can discuss options later.
GL
Terry
ps You may want to use the full edit feature to correct the title of this thread.

[Tracy1928]

Hi Terry.
Wow thanks for all of the info and I will look into it.
And thanks for the tip to change the subject of my original post. Makes sense.
Tracy

[Radioroslyn]

Hi
The bottom line is if you want to you can use the original speaker for it's FC and output transformer. Leave it connected as is. Find a suitable modern speaker that fit where the original one came from.Disconnect the two wires that go from the output transformer to the VC. Connect two new wires from the output transformer to the terminals on the replacement speaker. Leave old speaker in the cabinet
A few notes. Philco used odd size speakers. Most common replacement that will be close to the size you need is 8". ( I think your set uses the same size for the table and the console models) Philco used a 7 1/2" or so one. So you may need to do a little work to fit/mount the 8" job in there. Truth be told size doesn't matter so much but the impedance does.
The Philco speaker VC impedance is about 1 1/2 ohms. Modern standard speakers are either 4, 8, and 16 ohm. what you are looking for is the 4 ohm. It's the closest you can get and will work fine. This is the answer to your original question.
Hope all this helps
Terry
ps Don't know where you are located but if you near eastern PA big radio convention here Fri and Sat.

[jerryhawthorne]

Tracy, let's just get back to the basics, do you have an ohm meter? If so, radio unplugged and the speaker plug off the back of the chassis, measure the resistance between the plug held in your hand. According the schematic attached as a link, there are 3 lines going to the speaker. Set you meter to perhaps 10K. All three lines should check the field coil and output transformer primary. If the measurements do this (the meter dips down to about 0), they are good. Report back please.
Jerry

http://www.nostalgiaair.org/PagesByModel...013793.pdf