radio

[Dale Uhrich]

I bought a vertical radio for my truck made by motorola. It is marked bat, grd, v.c., and s.fld . The bat and grd are understandable, but what about the others. It also has cr797724 on the radio

[Bob_Koch]

The v.c. stands for "voice coil". That's another way of saying speaker. One lead of the speaker goes to V.C. The other lead goes to ground. fld usually means "field". Not sure about the s.fld, or what kind of field that is.

Just a little mention regarding radios, if you have changed the polarity on your truck, or converted to 12 volt you will need to insure that your radio doesn't end up getting fried. Wouldn't want that to happen.

[Mario Loya B1B]

Dale, I just purchased a vertical radio (MoPar 802) for my truck, too. I am trying to figure out how to hook it up as well. It has four wires. One is labeled "6 Volt Fuse 4A" I assume this is the wire that will power the unit and should be wired with a 4amp fuse. the other 3 wires are bunched and are attached to a female connector, which from what I can see attaches to a male connector at the back of the speaker. That is all well and good, but my speaker doesn't have that male connector. The 3 wires that attach to the connector are labeled as follows, 2 wires labled "speaker 4ohm" and one wire labeled "speaker field 6 Volt".

The 2 wires make sense to me, because that is how you hook up a modern day speaker "+ -" , but what is this 3rd wire? a ground? Anyone?

[Bob_Koch]

Speakers work by moving a small coil (voice coil) inside of a large permanent magnet. Older radios used electromagnets to create this magnetic field. This was the "field coil". It was dc power that was sent to this coil to create the magnetism. In about the 50's these field coils were replaced with permanent type magnets.

Here's an article that may help explain:

http://www.tubesandmore.com/scripts/foxweb.dll/extpage@d:/dfs/elevclients/cemirror/ELEVATOR.FXP?page=TECHSPEAKER01

[Mario Loya B1B]

Bob, as always you are a welath of info. I am not sure if the speaker in my truck is a electromagnet or permanent magnet speaker. It appears that the previous radio only had 2 wires running to the speaker attaching to the terminal strip. Am I correct in assuming an electromagnet speaker would require a 3rd wire (to power the field coil) I have attached a photo of the speaker taken under my dash. I will probably remove the speaker to get a better look at it, since I don't even know if it works.

[Mario Loya B1B]

Evening, Reg!

No. I have an 802. Even have a copy of the installation instructions. Hey, I should send that to Bob for the DPETCA site. I forgot I even had it until I started typing this.

Why do you ask, Reg?

Steve

Hey Steve, I recently purchased an 802 for my truck but am not quite sure how it mounts to the fire wall. The radio included the "L" shaped mounting bracket and was attached to the threaded post that sticks out of the back of the radio when it was shipped to me. Can you describe to me how it should be mounted, or better yet post a copy of those installation instructions you mentioned in a previous thread.

[Charles Furman]

Here is a picture of a Model 802 radio with the correct bracket for a pilothouse truck application. The "L" bracket you have fits the automobile applications. I hope this helps.

Charles

[Mario Loya B1B]

Now that makes more sense. I don't have that piece, but looks pretty easy to fabricate. Does this function as a ground, too?

[Steven Hood]

Hey Steve, I recently purchased an 802 for my truck but am not quite sure how it mounts to the fire wall. The radio included the "L" shaped mounting bracket and was attached to the threaded post that sticks out of the back of the radio when it was shipped to me. Can you describe to me how it should be mounted, or better yet post a copy of those installation instructions you mentioned in a previous thread.

Mario,

Yes, I can try and get them scanned here in the next couple of days for posting. I have a list of things I am looking up for people here, so please be patient. My scanner only holds 9x12, so I will have to check out the size of the instructions.

[Bob_Koch]

Mario, that coil of wire on the back is an electromagnet. The voice coil is behind the paper speaker cone and can't be seen. Since you only have two wires I assume the ground is being used as a third, common wire.

You could test this with a small battery, a 1.5volt flashlight battery of any size should work. Connect one side of the battery to the speakers metal frame (ground). touch the other side of the battery to one terminal. Then try the other terminal. The cone should move when one of them is touched. The one that doesn't move the coil is the electromagnet connection. You may even get a metal screw or something small to be drawn to the back of the speaker with the magnet energized.

Let me know how it goes.

Any instructions and schematics you guys can forward or mail me I'll post on the web

[Bob_Koch]

Steven,

If you want just throw them in the mail to me. If my scanner won't handle the size then the copy machine at work will. It has a built in scanner that I can download from. I've got time this week to do some of these things.

[Mario Loya B1B]

Bob, I removed the speaker from the dash and tried the test you recommended. I didn't see any movement in the speaker, but did hear static when the wire touched the terminal post where a green wire is currently connected. I assume this is the field coil connection. Ironically (or by no coincidence) the wire from my "new" radio that is labeled field coil is green. Now after making that connection, I will have 2 remaining wires that need to be connected to the speaker. FYI - these wires look like lamp cord. I guess I will connect those to the 2 remaining posts and if I don't get any sound will just reverse them. i assume i am not going to fry anything by doing this.

I installed the radio in the dash cutout by fabricatiing a bracket (thanks for the reference picture Charles). It is real sturdy but still needs a little tweaking to be perfect. I attached the wire that powers the radio using a 14amp fuse. The radio now turns on (lights up, but no music yet. i need to figure out the speaker connection) When on, the radio does produce a very audible humming sound. Is that to be expected with these old radios?

[Steven Hood]

For everybody that is looking for the instruction sheet for the Motorola 802. I am mailing it to Bob Koch, probably right after Christmas, to be scanned. My scanner will not work, as it is too small. Sorry for the inconvenience, but it will be on the website soon.

Steve

[Mario Loya B1B]

http://www.youtube.com/watch?v=Abc4JOsJtGc

Take a look at this video I made. Santa was good to me. I now have 2 radios to listen to in the truck. One is the 802 which I got working just a few hours ago. I still need to tweak the mounting bracket to get it to fit well in the dash cutout, but I'm getting good sound out of it. See for yourselves. The other is a speaker accessory for my iPod. I really like the way it mounts. Can easily be dismounted to take to the beach, prevent theft, etc.

[Merle Coggins]

Nothin' like a little Skynyrd to get things rollin'

Cool video.

Merle

[Bob_Koch]

The man has his truck and he has his tunes. What more could we ask for?

Great going.

[Bob_Koch]

Mario's video prompts me to ask a question - What other vehicles put the radio on the drivers left side. I kinda think it's cool, but I don't recall ever seeing any other manufacturers do this. Was Dodge the only one?

[Vintrader]

1950 DODGE TRUCK RADIO

MODEL MOPAR 802. IT HAS 7 CROME PUSH BUTTOND AND A VOLUME AND TUNE AHAFT AT THE BOTTON NO KNOBD AND TUNING GLASS WITH #S VERTICAL BESIDE BUTTONS 1950 DODGE TRUCK RADIO STORED IN MY GARAGE FOR 25 YRS.I DONT KNOW IF IT WORKS BUT ITS A GOOD PLACE TO START. 48 AND 49 HAD ROUND BUTTONS,50 AND UP HAS SQUARE ONES?

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=150088117158&fromMakeTrack=true

[49Bseries]

Anyone ever figure out the dimensions for the truck bracket? I would like to make one up so that I can finally install the radio.