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Consoles => Magnificent Magnavox => Topic started by: PanAm on July 26, 2017, 12:07:31 PM

Title: 1962 Magnavox Astrosonic Stereo Theatre
Post by: PanAm on July 26, 2017, 12:07:31 PM
Hello, 
I recently aquired a Magnavox stereo theater for $90. It seems to be in immaculate condition and it was originally owned by a couple with no children. When they died, all their furniture was sold with their house. I got the stereo from the people who bought the house. It had been sitting in their garage for 5 years and was unused for a while when it was still in the living room. Everything works like it should except the right side speakers. On radio and stereo phono I get nothing out of them. Same when it is on TV. Already tried tinkering with the balance and was able to get the left side louder but still not sound out of the right. I do not want to rip this thing apart trying to figure out the problem and I am not good with electronics let alone vintage stereo consoles. Now if it was a tube that needs replaced I am capable of doing that. I also wanted to know some background info on this console. I have googled and I can't find another like it. The only reason I know it is from 1962 is because it was in the 1962 Magnavox Catalog in the downloads center. It is the Scandinavia one. It seems to be quite rare. Any info about the stereo or the speaker issue is greatly appreciated. I will include some pictures if someone could help me figure out how to post them. Thank you!
Title: Re: 1962 Magnavox Astrosonic Stereo Theatre
Post by: amglow on July 26, 2017, 12:12:30 PM
Pictures, please. We like to see lots of pictures! :)
Title: Re: 1962 Magnavox Astrosonic Stereo Theatre
Post by: PanAm on July 26, 2017, 12:27:33 PM
I'm unsure of how to post pictures. Can you help me? I just joined.
Title: Re: 1962 Magnavox Astrosonic Stereo Theatre
Post by: electra225 on July 26, 2017, 06:25:09 PM
Congratulations on your Stereo Theater.  I have been looking for one for two years now.

I would respectfully suggest that if your instrument says "Astro-Sonic" on it anywhere, it is neither an all-tube model nor a 1962 model.  Astro-Sonic is Magnavox nomenclature for their new line of solid state instruments introduced in mid-1963.  They were sold along side certain left-over tube models, many times in the same or similar cabinets.  A genuine 1962 Stereo Theater would have an all-tube stereo with a 23", 24", or 27" all-tube black and white TV chassis.  An Astro-Sonic model would have a solid state stereo with a tube TV.  Color TV was available in a Stereo Theater for the first time in 1963. 

If you have an Astro-Sonic model, and you are experiencing a problem with a channel, I would suggest you clean the controls, particularly the function switch and external speaker switches.  It is possible you need to replace certain electrolytic capacitors in the amplifier to restore function to the dead channel.  Good luck with your Stereo Theater.
Title: Re: 1962 Magnavox Astrosonic Stereo Theatre
Post by: PanAm on July 26, 2017, 07:04:55 PM
Congratulations on your Stereo Theater.  I have been looking for one for two years now.

I would respectfully suggest that if your instrument says "Astro-Sonic" on it anywhere, it is neither an all-tube model nor a 1962 model.  Astro-Sonic is Magnavox nomenclature for their new line of solid state instruments introduced in mid-1963.  They were sold along side certain left-over tube models, many times in the same or similar cabinets.  A genuine 1962 Stereo Theater would have an all-tube stereo with a 23", 24", or 27" all-tube black and white TV chassis.  An Astro-Sonic model would have a solid state stereo with a tube TV.  Color TV was available in a Stereo Theater for the first time in 1963. 

If you have an Astro-Sonic model, and you are experiencing a problem with a channel, I would suggest you clean the controls, particularly the function switch and external speaker switches.  It is possible you need to replace certain electrolytic capacitors in the amplifier to restore function to the dead channel.  Good luck with your Stereo Theater.

You are correct. I forgot that Astro-Sonic was used starting with solid state in 63. It is all tibe with a black and white television. I haven't pulled the back off yet to see what the problem is with the balance. The balance screw in the bottom of the bass knob only seems to make the left speaker louder, and does not bring in the right side. Would it need a new tube? Keep in mind this is my first stereo and am very unfamiliar with the electronics.
Title: Re: 1962 Magnavox Astrosonic Stereo Theatre
Post by: TC Chris on July 26, 2017, 07:39:01 PM
We all hope for the quick fix of a new tube.  However, tubes are actually fairly durable, and it's often something else.  You have already seen the suggestion of cleaning controls, especially speakers.  That's a first step. Caig makes their DeOxit line of cleaners that are generally admired for being effective.   http://caig.com/

Sometimes you can get an oxidized switch to work--a little, and intermittently--by just working it back and forth.  And the same thing goes for tubes.  Their pins can make bad contact wit the socket.  Try wiggling them in the sockets.  Don't get ham-handed and break anything.  Just wiggle some.  Or better still, use some DeOxit on the tube pins and sockets.

If you don't have access to a tube tester, you can sometimes test by moving the right-channel tubes to the left channel and vice-versa.  If the problem follows the tubes, it's a tube.  If not, it's something else.  It's in the amplifier that you'll find discrete right and left tubes.  And the amplifier is probably most likely the place to make no noise from one channel.

Chris Campbell
Title: Re: 1962 Magnavox Astrosonic Stereo Theatre
Post by: PanAm on July 26, 2017, 08:03:54 PM
We all hope for the quick fix of a new tube.  However, tubes are actually fairly durable, and it's often something else.  You have already seen the suggestion of cleaning controls, especially speakers.  That's a first step. Caig makes their DeOxit line of cleaners that are generally admired for being effective.   http://caig.com/

Sometimes you can get an oxidized switch to work--a little, and intermittently--by just working it back and forth.  And the same thing goes for tubes.  Their pins can make bad contact wit the socket.  Try wiggling them in the sockets.  Don't get ham-handed and break anything.  Just wiggle some.  Or better still, use some DeOxit on the tube pins and sockets.

If you don't have access to a tube tester, you can sometimes test by moving the right-channel tubes to the left channel and vice-versa.  If the problem follows the tubes, it's a tube.  If not, it's something else.  It's in the amplifier that you'll find discrete right and left tubes.  And the amplifier is probably most likely the place to make no noise from one channel.

Chris Campbell

Thanks Chris for your help. I will pull the back off soon to see if there is anything visibly wrong like disconnected wires or such. In the meantime, if I were to go about the DeOxit, how would I get it into the places it is needed in? I don't want to have to rip it apart. I also need to know how much to use.
Title: Re: 1962 Magnavox Astrosonic Stereo Theatre
Post by: TC Chris on July 26, 2017, 08:24:45 PM
You can get it in aerosol spray cans or, as I prefer, a pump-action can.  For switches, I like to use a small artist's brush.  Pump some DeOxit into a small container and use the brush to apply it to the contacts on a wafer switch.  For enclosed switches, you may have to squirt some in via whatever opening is available.  You do have to remove the chassis from the console to do most of this, although some devices have speaker selector switches mounted externally, I think.  For tubes, if wiggling produces some effect, you could try applying some DeOxit to the tube pins alone, or maybe to the socket also via a small toothpick.  That wouldn't require removing a chassis either.

Chris Campbell
Title: Re: 1962 Magnavox Astrosonic Stereo Theatre
Post by: PanAm on July 26, 2017, 09:28:09 PM
You can get it in aerosol spray cans or, as I prefer, a pump-action can.  For switches, I like to use a small artist's brush.  Pump some DeOxit into a small container and use the brush to apply it to the contacts on a wafer switch.  For enclosed switches, you may have to squirt some in via whatever opening is available.  You do have to remove the chassis from the console to do most of this, although some devices have speaker selector switches mounted externally, I think.  For tubes, if wiggling produces some effect, you could try applying some DeOxit to the tube pins alone, or maybe to the socket also via a small toothpick.  That wouldn't require removing a chassis either.

Chris Campbell

What switches are you referring to? The speaker selectors on the radio panel and the balance screw? Or are there internal switches you may be referring to?
Title: Re: 1962 Magnavox Astrosonic Stereo Theatre
Post by: TC Chris on July 26, 2017, 09:34:06 PM
I'm not familiar with your specific unit.  Exploration is part of the fun of these things.  A dirty speaker switch, wherever it is located, can create your problem.  I have an old but nice Sherwood receiver.  The contacts in the headphone jack get crummy and one channel's speaker cuts out.  Each time it does,  I think it's an amp problem and replace the receiver with another.  Slow learner, I guess.  We always assume the worst instead of seeking the simplest solution first.

Chris Campbell
Title: Re: 1962 Magnavox Astrosonic Stereo Theatre
Post by: PanAm on July 27, 2017, 05:50:54 AM
Ok. Thank you for your help. I will soon spray the DeOxit in some of the switches and rotate the tubes.
Title: Re: 1962 Magnavox Astrosonic Stereo Theatre
Post by: PanAm on July 27, 2017, 05:52:23 AM
Pictures, please. We like to see lots of pictures! :)

I have posted the pictures in the Members Gallery section of the Phot Gallery. They are listed under 1962 Stereo Theater. Let me know if there is any trouble viewing them.
Title: Re: 1962 Magnavox Astrosonic Stereo Theatre
Post by: electra225 on July 27, 2017, 07:02:11 AM
Model 1MV357, maybe?  Magnavox lead dress in their cabinets is notoriously sloppy.  You might check to see if one of the neutral wires (black) has come off a speaker or speakers on the affected channel.  That would be easy to happen, especially during a move.  The external speaker switch for your Stereo Theater is located above the TV tuner. 
Title: Re: 1962 Magnavox Astrosonic Stereo Theatre
Post by: PanAm on July 27, 2017, 09:03:21 AM
Electra225, you are correct about the model number. When I take off the back I will look for your suggestion. I plan to hook up extension speakers to the unit and see if the right extension speaker doesn't work. Then I know something must be wrong with the right side of the unit and the balance is off. I will post about my findings and see if you guys have any suggestions. When I pull of the back I'll take some photos of the inside and add them to the gallery and see if your trained eyes can see something wrong that I can't. In the meantime, I will continue enjoy my Maggie.
Title: Re: 1962 Magnavox Astrosonic Stereo Theatre
Post by: electra225 on July 27, 2017, 09:38:07 AM
If there is a wire off the speakers, the external speakers may not work.  It depends on model series and how the set is wired.  The neutrals are typically connected together.  I have only experienced one instrument with a weak channel.  The problem turned out to be a 6EU7 in the tuner, used as an audio amplifier.  If your instrument has any 6EU7's at all they are immediate suspects.  If a neutral wire was disconnected, a channel or speakers on a channel would be totally dead.  You might want to take a close look at audio tubes in the tuner.  Subbing works well, if you have spares.  Good luck.
Title: Re: 1962 Magnavox Astrosonic Stereo Theatre
Post by: PanAm on July 27, 2017, 10:09:43 AM
I know I probably seem annoying, but I have no idea what a 6EU7 is. Could I just take a picture of the components inside the console and then post them and then you can point them out individually? I have no background in electronics and I'm trying to save a buck and get this right channel to work so I don't have to have it repaired.
Title: Re: 1962 Magnavox Astrosonic Stereo Theatre
Post by: Bill on July 31, 2017, 11:44:07 AM
6EU7 is a tube.  It's one of the smaller ones with the small pins.  Pictures are always good.

Bill
Title: Re: 1962 Magnavox Astrosonic Stereo Theatre
Post by: Motorola Minion on July 31, 2017, 12:02:08 PM

If yours has 6EU7 preamp tubes instead of the standard 12AX7, that is THE last all-tube console.

If it is like my Normandy Symphony of the same year, the tuner is a 79-series and your amp is a 9300-xx series. The four output tubes would be 6BQ5 then. You also might have the separate multiplex adapter as well. A very interesting combo, and probably has the horns instead of the pair of cone speakers.

Get inside this thing and wiggle the tubes a bit. I had to replace a bad tube socket in mine.
Title: Re: 1962 Magnavox Astrosonic Stereo Theatre
Post by: PanAm on August 05, 2017, 12:22:17 PM
Thanks for your suggestions. I will get inside it soon to troubleshoot and take some photos.
Title: Re: 1962 Magnavox Astrosonic Stereo Theatre
Post by: PanAm on August 11, 2017, 11:32:00 AM
Haven't had time to get inside yet, but I did look through the ventilation holes on the tuner side and I saw what looked like amber colored glass on the floor. Is it possible something exploded and that's why I am not getting sound from the right channel?
Title: Re: 1962 Magnavox Astrosonic Stereo Theatre
Post by: TC Chris on August 11, 2017, 05:10:42 PM
The usual reply to "is it possible?" questions is "anything's possible."  It's really easy to get the backs off, and then you can see what's actually happening.  Sometimes a tube that has lost vacuum (cracks, etc.) may show some orange-ish color.  But really, guessing at what might be wrong doesn't really get you anywhere.  Open it up and have a look-see.

Chris Campbell
Title: Re: 1962 Magnavox Astrosonic Stereo Theatre
Post by: PanAm on August 11, 2017, 05:55:40 PM
It will definitely happen within the next week.
Title: Re: 1962 Magnavox Astrosonic Stereo Theatre
Post by: PanAm on August 14, 2017, 08:16:53 AM
Here's the pictures of the inside. Let me know if there is anything visibly wrong that would cause the right channel not to have sound or if you have trouble viewing.
Title: Re: 1962 Magnavox Astrosonic Stereo Theatre
Post by: PanAm on August 14, 2017, 08:19:23 AM
Some more:
Title: Re: 1962 Magnavox Astrosonic Stereo Theatre
Post by: electra225 on August 14, 2017, 09:14:49 AM
Check or replace V3, the 6EU7 in the tuner.  6EU7's came out in the 1961 models of the 8800 and 9300 series of amps and their corresponding tuners.  Magnavox used the 6EU7 twin-triode due to its low-noise characteristics.  They tend to short cathode to filament and one half tends to die.  I have found the 6EU7 problematic and is always a suspect when I encounter a performance problem.  It is entirely possible that one half of that tube is dead, causing the dead channel.  This is only a "guesstimation", based on experience, since I have not laid eyes on your instrument.  Also suspect control switches of being electrically "dirty" such as the function switch and the external speaker switch.  There are two 6EU7's in the amp, these should be tested and subbed for the same reasons noted above.  A schematic and directed electrical testing, guided by a schematic, is your best procedure for troubleshooting.  Good luck.

Look on the diagram you posted for locations of the 6EU7's. 
Title: Re: 1962 Magnavox Astrosonic Stereo Theatre
Post by: PanAm on August 14, 2017, 12:15:39 PM
Thanks for your input. I don't have a tube tester and I don't really want to mess around with testing them so I will probably end up buying new 6EU7s. You previously mentioned DeOxit. Is there an acceptable substitute for it that I can buy at the store or is my best bet just to buy the brand name?
Title: Re: 1962 Magnavox Astrosonic Stereo Theatre
Post by: TC Chris on August 14, 2017, 07:24:53 PM
Here's the pictures of the inside. Let me know if there is anything visibly wrong that would cause the right channel not to have sound or if you have trouble viewing.

The 5th photo down shows a press-on connector--the kind often used for speakers--that is not pressed on to anything.  Maybe a speaker lead is disconnected?  Can't tell from the photo.

Chris Campbell
Title: Re: 1962 Magnavox Astrosonic Stereo Theatre
Post by: TC Chris on August 14, 2017, 07:26:33 PM
Some more:

Last photo here--TWO connectors not connected.

Chris Campbell
Title: Re: 1962 Magnavox Astrosonic Stereo Theatre
Post by: electra225 on August 14, 2017, 09:10:21 PM
I saw the disconnected wire and thought it might be a wire for the AM antenna.  It has to be disconnected to remove the back.  It is a black wire.  If that black wire was disconnected from the amplifier, all the speakers would be dead.  I can't see the speaker wires well enough in the photos to really tell.  I have been wrong before.  Naturally, if a wire is disconnected, that would be a problem.  The FM antenna uses twin lead.  Good call, Chris.
Title: Re: 1962 Magnavox Astrosonic Stereo Theatre
Post by: PanAm on August 15, 2017, 12:10:03 PM
Here are some pictures of those disconnected black wires. They were either disconnected when I bought the unit or I accidentally disconnected them when I removerd the back. I have no idea what they plug into. Also included are pictures of the speaker connections.
Title: Re: 1962 Magnavox Astrosonic Stereo Theatre
Post by: PanAm on August 15, 2017, 12:16:01 PM
And here's the last ones:
Title: Re: 1962 Magnavox Astrosonic Stereo Theatre
Post by: electra225 on August 15, 2017, 09:01:48 PM
External speaker wires.  Unless my eyes are not looking correctly, that terminal strip on the back is not wired correctly.  There should not be two black wires.  All the commons are supposed to be connected together.  That not being wired right might just kill one set of speakers.  Refer to the sticker pasted in the cabinet that you posted a picture of.  Somebody has had this apart before, witness the pieces of tape with numbers on it.  Before you go any farther, I would seriously suggest you make sure the speakers are wired right.  The console should play without the back on and without the external speaker terminal wired up.  See if your dead speaker(s) work with the back off like it is. Could you post a head-on picture of that external speaker terminal?  Not at an angle like it is now.  I'd like to see how the second black wire is connected.

Edit.  The pictures you just posted show the speaker in the top picture missing a wire.  It needs that wire re-connected.
Title: Re: 1962 Magnavox Astrosonic Stereo Theatre
Post by: PanAm on August 16, 2017, 09:28:48 AM
The speaker tab that is missing a wire isn't supposed to have a wire connected to it if I am reading the schematic correctly. It is exactly like that on the left side too and that is the side that is working correctly.
Title: Re: 1962 Magnavox Astrosonic Stereo Theatre
Post by: PanAm on August 16, 2017, 09:31:14 AM
The last one:
Title: Re: 1962 Magnavox Astrosonic Stereo Theatre
Post by: electra225 on August 16, 2017, 09:50:21 AM
The diagram showing speaker connections is drawn a bit differently than I have seen.  There is a "2-1-C" terminal, shown below the external speaker terminal on the back.  I don't see that terminal in your pictures.  It shows that double black wire.  Perhaps that is where the two loose black wires connect.  I don't see on the diagram any indication that any speaker will have an open terminal, but if the channel that works is like that, so be it. 

As an aside, and something I have wondered about, the TV chassis power plug is powered from the tuner chassis.  The TV has its own power supply, rectifier and that, apparently?  And an RCA-style jack with a wire going to the function switch for audio and the function switch providing power to the TV chassis?

You could reverse the speaker connections on the amplifier, shown behind the output transformers, to see if the dead speakers work.  That will tell you if the problem is in the speakers or their wiring or in the electronics.  After you are satisfied that the speakers work and are wired right, you can troubleshoot the electronics with confidence.  Hang in there.  You're doing fine!
Title: Re: 1962 Magnavox Astrosonic Stereo Theatre
Post by: PanAm on August 16, 2017, 11:16:45 AM
Thanks for the reassurance electra225. I am so scared I am going to break this thing though. The double black wire comes out of the remote stereo channel 2 port on the back panel but is looped into the remote stereo channel one port and the extension channel one port. My question is, where do the double black wires connect to inside the unit? You are correct about the tv having its power source from the tuner. Only way to turn on the tv is to put the knob on tv.
Title: Re: 1962 Magnavox Astrosonic Stereo Theatre
Post by: PanAm on August 16, 2017, 11:22:45 AM
Just noticed the woofer on the right side is missing a wire. Is it supposed to connect to one of the double black wires? Also the woofer on the left has blue, green, and two black wires going into it. The schematic makes no mention of a blue wire? Is it possible someone was in the middle of rewiring it and gave up? Also, how do I reverse the speaker input? That would be a great way to narrow down the issues.
Title: Re: 1962 Magnavox Astrosonic Stereo Theatre
Post by: PanAm on August 12, 2018, 07:08:58 PM
Hey guys,
Iíve been on a hiatus for a while, lifeís got in the way. I pulled out the 6EU7 in the tuner you guys suggested to do. It was wrapped with a metal tube that it easily slipped out of. I looked it over, too prongs were bent about so I straightened them. I put it back in, turned on the stereo, let it warm up a bit. As soon as the needle touched the record, the speakers made a horrible screeching sound, like a high pitched police siren. I know itís not the changer as I have not messed with it at all because it works like a charm and was working fine two minutes earlier. All evidence points to the tube. I ordered a new one online. Am I correct in my assumption and where should I go from now?
Thanks,
Jack
Title: Re: 1962 Magnavox Astrosonic Stereo Theatre
Post by: electra225 on August 12, 2018, 10:57:37 PM
The sleeve the tube was in was a tube shield.  I needs to be there.  The screeching is probably not caused by that tube or any tube.  More likely an open ground in the cartridge wiring somewhere.  Or anywhere.  Does it screech in another mode of the function switch?  Does it screech in FM?  Or AM?  If not, the problem is in the phonograph somewhere.  If it does, then you need to look elsewhere.  How did the tube pins get bent?
Title: Re: 1962 Magnavox Astrosonic Stereo Theatre
Post by: PanAm on August 13, 2018, 06:57:59 AM
I did not check to see if there was screeching in the radio or not. I just shut it off immediately. By cartridge do you mean the needle cartridge? If so, I had zapped myself earlier that evening touching the underside of the tone arm but never gave it any thought as I figured it was always like that. I will attach a picture of the underside of the tone arm.
Title: Re: 1962 Magnavox Astrosonic Stereo Theatre
Post by: PanAm on August 13, 2018, 07:05:51 AM
Some pics of the underside of the tone arm:
Title: Re: 1962 Magnavox Astrosonic Stereo Theatre
Post by: Bill on August 13, 2018, 07:39:59 AM
Greg was referring to the cartridge in the tone arm, if defective they will produce a horrible screeching sound.  I am more concerned that you got zapped touching under there.  Zapped like 110 volt zapped? 

Bill
Title: Re: 1962 Magnavox Astrosonic Stereo Theatre
Post by: PanAm on August 13, 2018, 09:28:34 AM
Zapped like I felt a vibration and I kept my hand on there and it started to sting a bit. Not anything serious, just knew I touched a live wire. I donít know if by picking it up from underneath I messed some of the wiring up, but all I know is it was working like a charm literally five minutes before that. I ordered a new needle a couple days ago. Should I also order a new cartridge too? Or is it just messed up wiring. I hope you can see in the pictures because my untrained eye canít tell.
Title: Re: 1962 Magnavox Astrosonic Stereo Theatre
Post by: electra225 on August 13, 2018, 10:57:51 AM
That looks like a Euphonics cartridge.  I have only owned one.  The compliance was all wonky on it, so I subbed it for an EV 26.  Getting zapped, even gently, is not normal nor is it good.  Something is not right.  Sounds like it is time for some serious troubleshooting.

First thing I'd recommend is to see if the screeching is in all modes of the function switch.  Then take it from there.
Title: Re: 1962 Magnavox Astrosonic Stereo Theatre
Post by: PanAm on August 16, 2018, 08:19:57 PM
Alright guys, I replaced the 6EU7 in the tuner. That didnít solve the speaker issue. On a good note, the screeching noise is not in any of the other modes. Now I need to figure how to get and install a new cartridge. Iím considering buying another changer like mine and using it for parts and as a test unit. I still donít understand what the MPX adapter does or if mine even has one. Would that have anything to do with it? Sorry about that barrage of info and questions. At least I can eliminate that tube as a possible suspect.
Title: Re: 1962 Magnavox Astrosonic Stereo Theatre
Post by: amglow on August 16, 2018, 08:39:16 PM
The MPX decoder was an add on for early 1960's FM tuners to allow the tuner to decode the two separate channels from the transmitted FM signal.  Many companies built in the option to plug in an external MPX decoder so one can easily update their current tuner after the FCC picked a decoding standard.  The FCC, in 1961, chose an MPX decode standard for stereo FM broadcasting in the United States.  All later tuners now have the MPX decoder built in to the FM tuner.
Title: Re: 1962 Magnavox Astrosonic Stereo Theatre
Post by: PanAm on August 16, 2018, 08:54:35 PM
So,
What happened before they were able to decode the two signals? Sound only play out of one aero of speakers or was the FM signal not as strong?
Title: Re: 1962 Magnavox Astrosonic Stereo Theatre
Post by: amglow on August 16, 2018, 09:06:45 PM
There was no two-channel FM broadcast prior to 1961.  Everything was monophonic.  Even today if you have a mono FM broadcast tuner, it will decode embedded data as one combined audio signal.  A tuner with MPX decoder will decode and separate the audio to its requisite left and right channels.
Title: Re: 1962 Magnavox Astrosonic Stereo Theatre
Post by: PanAm on August 16, 2018, 09:57:43 PM
Oh! I understand now. Thank you for clearing that up for me.
Title: Re: 1962 Magnavox Astrosonic Stereo Theatre
Post by: walyfd on August 17, 2018, 04:22:16 AM
"Stereo" FM was simulcast prior to 1962.  It only works on units with both an AM and FM tuner.  Stations would, and sometimes only at certain times of the day, air one channel on their AM band and the other channel on their FM band. 

So you set it to AM-FM and one channel, like the one coming in on AM, was heard on the left speaker and the FM channel on the right...

I tried it on my Fisher.  We have a local talk radio station that airs on both bands and it was kinda stereo...