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Re: Airline 62-2704 Need Help [message #63365 is a reply to message #63348]

Fri, 09 July 2010 22:21

Encryptor
Messages: 16
Registered: June 2010
Location: Central Bridge, NY

Chancellor

Yes it doesn't look like there are any rips. They say it works so we'll see when I get it. I was surprised they took less than half of what they were asking for it. Must have wanted to get rid of it. Hopefully it will work ok when I get it.

Bill

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Re: Airline 62-2704 Need Help [message #63368 is a reply to message #63365]

Sat, 10 July 2010 08:09

Wayne Parham
Messages: 18784
Registered: January 2001

Illuminati (33rd Degree)

Let us know when it arrives. Be sure to identify the field coil and voice coil windings, and measure them to make sure neither one is open.

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Re: Airline 62-2704 Need Help [message #63456 is a reply to message #63328]

Tue, 20 July 2010 16:48

Encryptor
Messages: 16
Registered: June 2010
Location: Central Bridge, NY

Chancellor

Wayne Parham wrote on Tue, 06 July 2010 11:11

That's the best way to find the schematics. Sorry I didn't have time to get the CD's out of storage, lots going on what with a 3-year-old running around and a million little projects. Everything seems to take months longer than it should, but that's just the way it is for a few years. So anyway, I'm glad you can scan through the Rider collection yourself. That's the only way to do it.

If you could and whenever you get time I'd appreciate it if you could get your CD's out of storage. Not to help me look but I may have found one that fits my chassis and I'd appreciate your opinion on it. Thanks.

Bill

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Re: Airline 62-2704 Need Help [message #63457 is a reply to message #63368]

Tue, 20 July 2010 16:50

Encryptor
Messages: 16
Registered: June 2010
Location: Central Bridge, NY

Chancellor

Wayne Parham wrote on Sat, 10 July 2010 08:09

Let us know when it arrives. Be sure to identify the field coil and voice coil windings, and measure them to make sure neither one is open.

The speaker arrived while I was on vacation. It's HUGE! lol

All the wires go into a single plug. On my chassis there are only 2 wires that say speaker but there are 3 wires I think that come from a small transformer that are taped up. I think they may go to the field coil of the speaker but I'm not sure.

Bill

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Re: Airline 62-2704 Need Help [message #63461 is a reply to message #63457]

Tue, 20 July 2010 22:18

Wayne Parham
Messages: 18784
Registered: January 2001

Illuminati (33rd Degree)

That plug is convenient, but of course, you have to have its mate to use it. Otherwise, you'll just have to wire in direct.

The speaker has two coils, one (voice coil) that is wrapped around the moving former attached to the cone. The other (field coil) is stationary, wrapped around the center pole that the voice coil former moves up and down on. The voice coil winding goes to the output transformer, and the field coil winding connects to the power supply, usually in series with B+, with the rectifier output on one side and all other tube anodes connected to the other side.

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Re: Airline 62-2704 Need Help [message #63534 is a reply to message #63461]

Mon, 26 July 2010 20:10

Encryptor
Messages: 16
Registered: June 2010
Location: Central Bridge, NY

Chancellor

I'm not sure what you said but it sounds complicated. *lol*

I received the speaker and I thought it was rather large so I measured it. It's a 12" speaker not the 10" that it was advertised as. I'm not sure what I'm going to do from here. I think I've found a diagram that matches my chassis. The schematic only shows 2 wires going to the speaker and the picture of the back of the cabinet shows a speaker that doesn't look like it has a transformer on it but it's not a great picture.

Bill

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Re: Airline 62-2704 Need Help [message #63541 is a reply to message #63534]

Mon, 26 July 2010 23:21

Wayne Parham
Messages: 18784
Registered: January 2001

Illuminati (33rd Degree)

Well, I suppose you could mount the speaker if it will fit inside the cabinet. The hole will be smaller but for AM broadcast, that's probably OK. Then again, if it means you have to tear anything up to get it in there, I'd probably get a speaker that was the right size.

The thing that concerns me right now is the matter of the field coil. You really need to identify if the radio originally had a speaker with a fixed magnet or a speaker with a field coil. If it had a field coil, there will be four wires going to it, two to the field coil and two to the voice coil. Most old tube radios are this way, using a field coil speaker. Honestly, I can't imagine the radio pictured in your first post having a fixed magnet speaker in it. But if it used a fixed magnet, then you won't have a field coil output. It is important to know what you have, so you'll know what you need.

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Re: Airline 62-2704 Need Help [message #63545 is a reply to message #63541]

Tue, 27 July 2010 19:46

Encryptor
Messages: 16
Registered: June 2010
Location: Central Bridge, NY

Chancellor

I may be able to make it work with some wooden brackets off the screws that are there for the 10".

I know but that is difficult to do when the speaker is gone and there are no schematics that I can find for this specific radio.

Do a Google search for a Gamble-Skogmo inc. Model 43-6927 and a Model 43-7603. They look like the same chassis but the latter has the phonograph in it. The picture of the back of the cabinet of the first model is easier to see the speaker. I don't know if you can tell if it's a field coil speaker from the picture or not.

The problem again is I don't know if this is identical to the one I have although the chassis top view looks to be identical to mine.

Thanks again for your help.

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Gamble-Skogmo 43-6927 and 43-7603 [message #63546 is a reply to message #63545]

Tue, 27 July 2010 21:28

Wayne Parham
Messages: 18784
Registered: January 2001

Illuminati (33rd Degree)

Both schematics - the one for the Gamble-Skogmo Model 43-6927 and the Model 43-7603 - show a fixed magnet speaker in them.

However, the chassis was designed like most other tube radios, with a tube rectifier and a "pi filter", having a capacitor in shunt across the rectifier output, followed by a series inductor (the field coil) followed by another shunt capacitor.

In the case of the 43-6927 and 43-7603 radios, the field coil is replaced with a 1.8kΩ, 20 watt resistor (connected to pin 8 of the 6X5 tube). That way, a fixed magnet speaker can be used. But if you have a field coil speaker, you can take that resistor out and put the field coil winding in its place.

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Re: Gamble-Skogmo 43-6927 and 43-7603 [message #63559 is a reply to message #63546]

Thu, 29 July 2010 17:54

Encryptor
Messages: 16
Registered: June 2010
Location: Central Bridge, NY

Chancellor

In your opinion and looking at the picture of the chassis I posted at the beginning of this thread would you say that the model 43-7603 is the radio I have?

If so wouldn't it be better to put whatever speaker it came with back in it? If I decide to do that could I use any 10" speaker?

Should I decide to put the 12" field coil speaker I have where do I hook it to?

Bill

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