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RCA J2 45 changer.

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RCA J2 45 changer.

Postby Hugues TR4 » 16 Aug 2013 11:09

Hi All,

Bought my first TT back in '58 to play my 7" out of my pocket money.
Very proud I was indeed! It was a RCA J2 45 changer.
Happened to see that several of this model are currently sold on e-Bay, but with the US standards: 115V, 60 Hz 15 watts.
Before I succomb to the nostalgy temptation, I'd like to know if the conversion to European standards (220V, 50 Hz) is at all possible and at what cost with that kind of motors. Mine was of course adapted for Europe when bought but I lost trace of it after buying more sophisticated equipment a few years later..
I'd really like to retrieve my teenage sensations when listening to my 7" golden oldies which I have all kept.
Could anybody answer this question?
Many thanks in advance,

Cheers,

Hugh.
Dual 1019/Shure M97xE/Jico SAS stylus.
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RCA 45 J-2 RP 190 record changer (1952).
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Re: RCA J2 45 changer.

Postby Coffee Phil » 16 Aug 2013 18:04

Hi Hugues,

I'm not an expert on these machines but I'm pretty sure they use an AC induction motor. The speed of these motors is tied to the frequency of the power line. I'm guessing that that the capstan is machined into the end of the motor shaft so you probably can't change it without changing the motor. If you can find a motor / capstan for 50 Hertz that would be the "clean" method to convert. There are places in the US which restore those machines but I'm guessing they aren't likely to have 50 Hz parts. If you can find such a place in Europe they may have the 50 Hz motor.

It may be difficult to find the 50 Hz motor but there is an other option. You might try one of these car cigarette lighter AC converters. You can run it of a 12 Volt DC power supply. I think the motor in the player will tolerate the "modified" sine wave from the car AC converter. It may buzz a little.

If you are committed to owning one of these machines you might buy one off of eBay and get a US car AC adapter and give it a try. If the buzz is excessive or the frequency (speed) is off, you can then pop for a
real ($$$) sine wave converter.

Phil




Hugues TR4 wrote:Hi All,

Bought my first TT back in '58 to play my 7" out of my pocket money.
Very proud I was indeed! It was a RCA J2 45 changer.
Happened to see that several of this model are currently sold on e-Bay, but with the US standards: 115V, 60 Hz 15 watts.
Before I succomb to the nostalgy temptation, I'd like to know if the conversion to European standards (220V, 50 Hz) is at all possible and at what cost with that kind of motors. Mine was of course adapted for Europe when bought but I lost trace of it after buying more sophisticated equipment a few years later..
I'd really like to retrieve my teenage sensations when listening to my 7" golden oldies which I have all kept.
Could anybody answer this question?
Many thanks in advance,

Cheers,

Hugh.
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Re: RCA J2 45 changer.

Postby Hugues TR4 » 16 Aug 2013 19:42

Hi Phil,
Thanks a lot for your extensive reply.
Finding a 50Hz capstan motor could be a challenge indeed.
I've got a 220V to 12 V converter, meant to serve as a battery loader for several apps. But it gives DC current.
I've also got a 220 to 110 volts transformer, but I do not think it will have any effect on the Hz rate needed by the motor (or yes?)
I'm far from being an electric/electronic specialist.
So, if I understand rightly, you suggest to feed the AC motor with 12V DC current?
Please correct me if I'm wrong.
Thanks again!

Cheers,

Hugh.
Dual 1019/Shure M97xE/Jico SAS stylus.
Thorens TD 146 & TD 166/Ortofon OMB5 and OM40 carts.
Marantz Mod 6170/Marantz E 5000 cart.
RCA 45 J-2 RP 190 record changer (1952).
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Re: RCA J2 45 changer.

Postby w_axlrose1 » 16 Aug 2013 20:55

You won't be able to run an AC motor off DC current. Especially a 110v on 12v.

I think what he is suggesting is try and find a European 240v to 12v DC transformer. One of the ones that emulates a car cigar lighter socket. They're designed so that you can use 12v DC car accessories on household mains electric.

You can then buy a US inverter that does the reverse job. They are designed to produce 110v AC @ 60Hz from the 12v DC you get from the cigar lighter socket.

Put the two together and you should have a handy little converter that'll allow you to run your US made turntable off Euro electric.
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Re: RCA J2 45 changer.

Postby Hugues TR4 » 16 Aug 2013 21:11

Thanks Axlrose.
What should I look for on the net to find this US inverter you are mentioning?
I've already got a 220V AC to 12V DC converter.
How should I connect them together to produce these 115V AC 60 Hz?
As mentioned before, I'm a poor electrician and my experience is based on practical work only.
Thanks for your answer.

Cheers,

Hugh.
Dual 1019/Shure M97xE/Jico SAS stylus.
Thorens TD 146 & TD 166/Ortofon OMB5 and OM40 carts.
Marantz Mod 6170/Marantz E 5000 cart.
RCA 45 J-2 RP 190 record changer (1952).
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Re: RCA J2 45 changer.

Postby w_axlrose1 » 16 Aug 2013 21:25

Something like this should do the trick...

http://www.ebay.com/itm/300W-Car-Cigare ... 19cda9c8e5

I can't vouch for the quality of these things produce as I've never used one. But basically you'd connect like this

220v AC@50Hz =====> 220v to 12v DC =====> 12v DC to 110v AC@60Hz =====> Turntable

You will want to check what kind of current your 220 to 12v transformer can handle before you go ahead with this. If it is only capable of supplying mere mA then it won't be able to handle the demand.
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Re: RCA J2 45 changer.

Postby Hugues TR4 » 16 Aug 2013 21:35

Many thanks Axlrose: will try and investigate.
The 115V motor isn't yet in my possession, but I'll report as soon as I'll get it.
Cheers,

Hugh.
Dual 1019/Shure M97xE/Jico SAS stylus.
Thorens TD 146 & TD 166/Ortofon OMB5 and OM40 carts.
Marantz Mod 6170/Marantz E 5000 cart.
RCA 45 J-2 RP 190 record changer (1952).
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Re: RCA J2 45 changer.

Postby w_axlrose1 » 16 Aug 2013 21:44

I'll point out that I have never tried the above combination of two adapters to switch between the different mains standards but theoretically there shouldn't be any reason why it wouldn't work. If you do attempt this (not going to say you should) you'll need to make sure there is a real good connection between the two 12v interfaces. The current at this point will be extremely high and will cause any loose connection to get very hot. If you are going to wire them together you'll need to use thick cable and keep the length short between those two points.
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Re: RCA J2 45 changer.

Postby Coffee Phil » 16 Aug 2013 23:38

Sorry I got back a bit late.

Do not put DC into the AC motor. It will not work and you could ruin the motor. The DC supply which you have is to power a device such as this:

http://laszpower.amazonwebstore.com/BESTEK-75w-power-inverter-car-dc/M/B003Q54V88.htm

The record player is in turn powered by the device which I linked.

The inverter must be powerful enough to power your record player and the DC supply which you have must be powerful enough to power the inverter with the record player connected and playing. If you have at least 3.5 amperes it should be sufficient. A 40 Watt inverter should be sufficient for the record player. I believe you said it was 20 Watts.
You need an inverter from the US as I would expect one intended for Europe would be 220 Volts 50 Hz. Even with the US unit confirm that it is 60 Hz and that the frequency is accurate as that will effect speed and hence pitch. Contact the manufacturer and ask. Don't trust the retailer unless they are specifically an inverter supplier. The pitch accuracy will be no better than the frequency accuracy of the inverter.

There is an other possible issue. As I mentioned the output of these cheapie inverters is a modified sine wave. What this means is that it is a stair step approximation to a sine wave such that the RMS, average, and peak to peak voltages are the same however there are only about three steps in the positive part of the cycle and three in the negative part. This results in a huge amount of distortion. Motors vary in their ability to tolerate this. My experience is that shaded pole induction motors (the kind which you will have) tolerate this reasonably well. They may buzz a little due to the stair step voltage as apposed to the smooth sinusoid of "real" AC from the power line.
If the buzz turns out to be intolerable you may have to go to a true sine wave 60 Hz AC source. These do exist but they are not cheap.

The 220 Volt to 110 Volt transformer can be useful to quick check the functioning of the player however the machine wont be useful for listening as it will run at 5/6 of the correct speed. I can't imagine that pitch error being acceptable to anyone.

Phil



Hugues TR4 wrote:Hi Phil,
Thanks a lot for your extensive reply.
Finding a 50Hz capstan motor could be a challenge indeed.
I've got a 220V to 12 V converter, meant to serve as a battery loader for several apps. But it gives DC current.
I've also got a 220 to 110 volts transformer, but I do not think it will have any effect on the Hz rate needed by the motor (or yes?)
I'm far from being an electric/electronic specialist.
So, if I understand rightly, you suggest to feed the AC motor with 12V DC current?
Please correct me if I'm wrong.
Thanks again!

Cheers,

Hugh.
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Re: RCA J2 45 changer.

Postby Coffee Phil » 17 Aug 2013 06:47

I've been doing some checking. It seems that for the modified sine converters which state a frequency accuracy, it is +/- 3 Hz. That is abysmally poor for this application. I haven't found a spec on the true sine wave units and the places to call are now closed.

I have some of the cheapies in my lab. I'll open one up and see how the oscillator works. It for sure is not quartz with that lousy accuracy. I'll see if I can add a pot to tweak the frequency. If that works it can be a speed control and the turntable speed can be set with a strobe disc. I can't promise a time schedule, but I'll get on it. You may have to buy the converter and send it to me to do the "value added" and send it to you.

Phil
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Re: RCA J2 45 changer.

Postby Chiltern » 17 Aug 2013 08:51

Hi, your post made me think that I have 2 RCA machines to restore. One I dismantled maybe 10-12 years ago but at the time could not easily get a replacement for the rubber faced auto cam, so back in the box it went.

I will find it out and check out the motor. Years ago I worked on many American classic jukeboxes, these had the same problems with motor speed. Running on 50Hz with a transformer gave no problems, the standard mod for 50Hz by the 2 main jukebox manufactures that had flat platter designs (AMI & Rock-Ola) was to fit a spring over the standard 60Hz motor spindle to increase the od that the idler runs on.

With a little trial & error this is the way to go, I will post pictures of the motor later.

The Jukebox show at Rosmalen in Holland used to be a good source for these RCA machines.

Alan
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Re: RCA J2 45 changer.

Postby Hugues TR4 » 17 Aug 2013 11:20

@ Axlrose and Phil: A huge thank for your contribution!
All this really is very complicated and, after a quick check through the net, it seems that there is no easy solution to the problem. But I will keep the lectures in mind for future reference. In the meantime, the first thing to do is try and find a suitable motor or attempt to modify the pulley. But I do not know at this stage what the pulley in question looks like and if it allows any mod...
Will advise about the progress...
Many thanks to both of you again.
@ Alan: Nice surprise to hear that there are still J2 45 survivors this side of the pond! Looking forward to seeing your pics, my memories date back to my teens and wouldn't help in this case. At least, there were RCA J2 manufactured for export to Europe (I had one): wonder whether some would still come up in UK. That would solve the motor problem.
About your rubber faced autocam, I discovered on the net a chap who sells repair kits for our little beast: just google "V-M RCA 45 player parts". They sell idler wheels, cam wheels, new adaptable MM cartridges with diamond stylus, etc...
Worth a visit!
Thanks again for joining the forum.

Cheers to all,

Hugh.
Dual 1019/Shure M97xE/Jico SAS stylus.
Thorens TD 146 & TD 166/Ortofon OMB5 and OM40 carts.
Marantz Mod 6170/Marantz E 5000 cart.
RCA 45 J-2 RP 190 record changer (1952).
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Re: RCA J2 45 changer.

Postby Hugues TR4 » 17 Aug 2013 21:51

Well... Just bought one on e-Bay for 10 Bucks, waiting for delivery.
It looks complete but has to get through a full restoration (including esthetic), so I'm currently screening the net for info and parts opportunities.
By the way, if someone would have an owner or service manual for the RCA J2 to share, I would be grateful for ever!!!
By the way, the USPS rates are shockingly high! ( cost me 60 bucks to ship the beast home!) Seller couldn't believe it.
Many thanks for your interest!

Cheers,

Hugh.
Dual 1019/Shure M97xE/Jico SAS stylus.
Thorens TD 146 & TD 166/Ortofon OMB5 and OM40 carts.
Marantz Mod 6170/Marantz E 5000 cart.
RCA 45 J-2 RP 190 record changer (1952).
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Re: RCA J2 45 changer.

Postby analogaudio » 17 Aug 2013 23:44

only $60 that was cheap! It is the same high cost in the opposite direction. I think THEY want to make a lot of money out of shipping across the Atlantic. Happy Listening :-)
Ted

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Re: RCA J2 45 changer.

Postby Hugues TR4 » 18 Aug 2013 09:30

Thank you Ted,
It really is shocking indeed!
Maybe we should set up a TT transport company across the Pond, we might get some success!
Cheers,

Hugh.
Dual 1019/Shure M97xE/Jico SAS stylus.
Thorens TD 146 & TD 166/Ortofon OMB5 and OM40 carts.
Marantz Mod 6170/Marantz E 5000 cart.
RCA 45 J-2 RP 190 record changer (1952).
Hugues TR4
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