Are there 6vdc speakers?

[ojh]

On a current project I found the radio lying in the trunk fenderwell.  Looking it over I see a frayed wire and I thought I fix the wire, connect it to a 6v battery, connect a speaker and see if it works.  Then I thought what if the speakers are different voltage or polarity (positive ground system), can I connect a modern speaker to it?

[TerryB]

Speakers are rated in resistance in ohms for most basic ones.  Eight ohms is typical resistance for the speaker coil.  Usually two wires go to the speaker coil from the radio.   Post a pic if you can.

Edited December 12, 2020 by TerryB (see edit history)

[JimKB1MCV]

Best way to test your speaker would be to connect it to a working 6v positive ground radio, preferably to one that is in your car.

Not a good idea to put a battery across it.

If the radio was in the trunk, it may require service first. Not a good idea to just connect a battery to a radio of unknown condition, you may let the smoke out.

Good luck and stay well.

[Bloo]

Speakers are rated in impedance, not resistance. Both are measured in Ohms, but an ohmmeter only measures resistance.

 

6 volts vs 12 volts makes no difference at all, and neither does the polarity of the charging system, but there have been some screwy designs in car radios and the impedance could be literally anything. If you tell us what car it is, I might be able to guess... or not...

 

There is no conversion factor for ohms of impedance to ohms of resistance. That is because resistance is a DC measurement, and is always the same, while Impedance is an AC measurement, and will vary depending on the frequency (hertz) it is measured at.

 

There is, however, a happy accident in the case of speakers. A speaker will usually have a resistance (which you can measure) that is just a little less than the rated impedance. For instance, an 8 ohm speaker will measure about 6 ohms. A 4 ohm or 3.2 ohm speaker will measure more like 2 ohms.

 

A radio old enough to be 6 volts might take a special speaker with an electromagnet. That type of speaker may have been connected in series with the high voltage internally for the tubes, in which case the radio would not work without it. On the other hand, sometimes the electromagnet just runs on 6 volts.

 

EDIT: If it is a tube type radio with a vibrator be sure to get it serviced by someone who knows how before you put power to it. The buffer capacitor (for the vibrator) is almost certainly bad, and it will damage the vibrator. They aren't making any more of those.

 

 

Edited December 13, 2020 by Bloo (see edit history)

[TerryB]

Well yes it’s impedance and not resistance but for the novice the idea of dc resistance might be easier to grasp  and the speaker might actually have an ohm value stamped on it.  I didn’t want to go down the impedance road.  As correctly stated a dc ohmmeter will measure something close to the impedance of the speaker and is helpful to see if the speaker coil is still operating when checked for continuity.  Often a noise can be heard from the speaker when the ohmmeter is first connected.  The idea of it having an electromagnet is sure possible, a picture of the radio and speaker would help.  

[ojh]

Thanks for the replies, the car is a '52 Nash Healey, the radio may or maynot be original, the speaker has only 2 wires, theres no speaker anywhere in the car, there is no mfgr name of the radio.  I might be able to get started cleaning it up today.

 

[JimKB1MCV]

  As TerryB said, some pics would be in order, there was a lot of unbranded aftermarket car radios being installed  ' in the day'.

  Parts and service is available, mostly.

  Car is looking good.

[54vicky]

when I need to check a speaker I use a small battery (9 volt or less)has worked for me for almost 60 years.just touch the positive post while holding the other wire on the ground. you will hear a crackling sound do not hold on just touch.there are new updated vibrators available.there are radio repair shops that are qualified to  repair.

[Bloo]

I use a 1.5v battery for that. It won't do the original poster much good because his speaker is completely missing.

 

As for the new updated vibrators, they are solid state and are controversial. If you post about them on the antique radio forums you will probably get a 20 page argument with one side explaining how great they are and the other explaining that they have no "off" time when they switch, and as such are much harder on the power transformer, which will run hot and might be irreplaceable. I have no dog in that race.

 

For my own cars however, I will stick with the mechanical ones because in my opinion that noise they make when they start is as much a part of the experience as the music coming up slowly as the tubes warm. I won't have any "converted" radios either for the same reasons. It would be a shame to burn up a mechanical vibrator just because you didn't change the buffer capacitor.

 

 

[radioguybill]

Yes but with the Aurora Design SS vibrator you can have tube emulation. Where there's a warm up time and buzzing sound. In turning on the radio you have the option of While in the warmup period (change will be immediate): • tube warmup/vibrator sound -> tube warmup only • tube warmup only -> no warmup Within 4 seconds of turning the radio on (changes on next startup): • no warmup -> tube warmup/vibrator sound (a confirmation beep will be heard. With a twist of the tuning control.

 

Designed especillay for the judges

 

 

[ojh]

Speaking of sound, do you remember going to the matinee as a kid the sound of that single Klipsch speaker when they turned it on?

[JACK M]

5 hours ago, ojh said:

the sound of that single Klipsch speaker when they turned it on

 

I have a Klipsch sub on my home set up.

Its the real deal.

[ojh]

heres the radio

Theres no name or anything on it

[Bloo]

I think it is a 51 or maybe 52 full-size Nash radio. What year is your Nash Healey?

 

https://www.ebay.com/itm/1951-NASH-AM-PUSH-BUTTON-RADIO-WITH-FACEPLATE-AND-KNOBS-/203093936945

 

.

Edited December 17, 2020 by Bloo (see edit history)

[ojh]

14 hours ago, Bloo said:

I think it is a 51 or maybe 52 full-size Nash radio. What year is your Nash Healey?

 

https://www.ebay.com/itm/1951-NASH-AM-PUSH-BUTTON-RADIO-WITH-FACEPLATE-AND-KNOBS-/203093936945

 

.

Wow!  Look at that, thats it for sure.  The NH is a '52.  I haven't had a chance to test this one, I'm having to make an 'anti-chatter' rod for the clutch.  This car never had one and it shows it in the manual, I'm getting clutch chatter in my test drives so I'm copying what is shown in the shop manual for the car.  I'll probably get to the radio this weekend.  Thanks for posting that up, very good of you.

[28 Chrysler]

Some speakers have more than two wires. Some radios were designed to use an electro magnet that is also a choke for the power supply.

Duel voice coils discussion will not be included at this time.

Your radio will probably need all of the electrolytic capacitors changed to get it to work.  

[ojh]

21 hours ago, 28 Chrysler said:

Some speakers have more than two wires. Some radios were designed to use an electro magnet that is also a choke for the power supply.

Duel voice coils discussion will not be included at this time.

Your radio will probably need all of the electrolytic capacitors changed to get it to work.  

I once did a '59 Caddy and I think each speaker took 4 wires, it had a 'Transistorized' Radio and the sound that came out of it was priceless, Patsy Cline never sounded so good as coming from that radio.

[Bloo]

6 hours ago, ojh said:

I once did a '59 Caddy and I think each speaker took 4 wires, it had a 'Transistorized' Radio and the sound that came out of it was priceless, Patsy Cline never sounded so good as coming from that radio.

 

My mother had a 59 Cadillac. The only thing transistorized in hers was the audio output. The rest of it was 12 volt "space charge" and other low voltage tubes, so no vibrator was needed. The sound was amazingly good, as was the sensitivity. It's ability to pull in distant stations was phenomenal. Many GM cars of that era had similar Delco radios, and the slightly older ones with vibrators were also extremely good.

 

On 12/18/2020 at 8:44 AM, 28 Chrysler said:

Your radio will probably need all of the electrolytic capacitors changed to get it to work.  

 

I agree, and the paper capacitors too as they were still the default in 1951-52. They are likely to be in worse shape than the electrolytics this many years in. The buffer capacitor is still job one. Me? I would do it all and get it overwith.

[ojh]

18 hours ago, Bloo said:

 

My mother had a 59 Cadillac. The only thing transistorized in hers was the audio output. The rest of it was 12 volt "space charge" and other low voltage tubes, so no vibrator was needed. The sound was amazingly good, as was the sensitivity. It's ability to pull in distant stations was phenomenal. Many GM cars of that era had similar Delco radios, and the slightly older ones with vibrators were also extremely good.

 

 

I agree, and the paper capacitors too as they were still the default in 1951-52. They are likely to be in worse shape than the electrolytics this many years in. The buffer capacitor is still job one. Me? I would do it all and get it overwith.

Excellant!  I'll send it right on over to you, I was hoping somebody would offer.

Just kidding, just kidding.

[37_Roadmaster_C]

5 hours ago, ojh said:

Excellant!  I'll send it right on over to you, I was hoping somebody would offer.

Just kidding, just kidding.

 

NO FAIR!!  He is supposed to be fixing the one for my dads 37 Buick!!

 

Just kidding Bloo!!

[ojh]

18 hours ago, 37_Roadmaster_C said:

 

NO FAIR!!  He is supposed to be fixing the one for my dads 37 Buick!!

 

Just kidding Bloo!!

I'm just trying to figure out what these 'vibrators' are, why they need replacing and afraid to ask.

[28 Chrysler]

The vibrators are a electro mechanical way to turn DC to AC. A step up transformer is used in the power supply section of your radio and this supplies the high voltage for the tubes.

There are contact points inside that get dirty /corroded. The cover can be preyed off and the points cleaned.

[Bloo]

It is part of a mechanical version of what we call a "DC-DC Converter" today. Normal vacuum tubes need high voltage on their plates, maybe something like 100-250 volts in a car radio. Transformers only work on AC, and the voltage available in a vintage car is 6 or 12 volts DC. What to do? Make something like a giant buzzer that switches the polarity back and forth. Then you have AC that can be stepped up with a transformer.

 

Once you have high voltage AC, you need to convert that back to DC because the tube plates in the radio need DC. That can be done one of two ways. The first is with a "Synchronous Vibrator". It has more sets of points in the same vibrator, mechanically synchronized with the first sets of points, doing the exact opposite of what the first sets of points did. The second and more common way is to use a rectifier tube to convert the AC to DC, like a radio that plugs into the wall would do.

 

That muffled "BWWWwwwoommmmp" noise you hear when you turn on most car radios made before the late 50s is the vibrator starting up.

 

 

.

 

Edited December 21, 2020 by Bloo (see edit history)

[Frank DuVal]

15 hours ago, ojh said:

 

I'm just trying to figure out what these 'vibrators' are, why they need replacing and afraid to ask.

 

Just use the three terms (auto radio vibrator) together in your Google searches! Ha!🤣