1950's RCA 45 record player

radio, tape, stands and accessories
Hugues TR4
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Re: 1950's RCA 45 record player

Post by Hugues TR4 » 08 Apr 2015 09:09

@ Phil,

Extremely difficult to compare, as the 190 can be plugged directly into my HiFi combo, while the 168 belongs to a self contained record player in itself with built-in amp and speaker ( table top record player).
Only big difference is the heavier metal platter which could stabilize the speed and reduce the rumble a little.
My 190 (Mono) emits a reasonable rumble level up to VOL 12.00, higher, it gets disturbing, but I rarely use my HiFi higher than that volume anyway.
I'm using it mostly to play my old jazz mono 45EP's.
I'm exploring a way to connect the 168 PU directly into my amp, but only get a loud hum so far...

3012430125

But these little beasts gave me a lot of fun working on them and I enjoy listening to my old 7"'s with them.
I also like their vintage style and purely mechanical functionning.
Have you bought Phil Vourtsis' book? Think that's the RCA 45's bible!
Still ready to help you on an eventual 168 restoration.
Cheers,

Hugh.

Coffee Phil
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Re: 1950's RCA 45 record player

Post by Coffee Phil » 08 Apr 2015 22:28

Hi Hugh,

I do have to get that book. While it is tempting to play with an RP 168, I have to draw the line and say NO NEW PROJECTS until the Little Bear and my Citation 4 are done. Since I started the motor transplant on the Beogram 3000 about 20 years ago it should be next.

Is the amplifier in the unit with the RP 168 one of those "hot chassis" types? If so be careful. Do the motor windings power the amp? Where I'm going with all this is to figure a way to get the audio to your audio system.

Phil



Hugues TR4 wrote:@ Phil,

Extremely difficult to compare, as the 190 can be plugged directly into my HiFi combo, while the 168 belongs to a self contained record player in itself with built-in amp and speaker ( table top record player).
Only big difference is the heavier metal platter which could stabilize the speed and reduce the rumble a little.
My 190 (Mono) emits a reasonable rumble level up to VOL 12.00, higher, it gets disturbing, but I rarely use my HiFi higher than that volume anyway.
I'm using it mostly to play my old jazz mono 45EP's.
I'm exploring a way to connect the 168 PU directly into my amp, but only get a loud hum so far...

3012430125

But these little beasts gave me a lot of fun working on them and I enjoy listening to my old 7"'s with them.
I also like their vintage style and purely mechanical functionning.
Have you bought Phil Vourtsis' book? Think that's the RCA 45's bible!
Still ready to help you on an eventual 168 restoration.
Cheers,

Hugh.

Hugues TR4
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Re: 1950's RCA 45 record player

Post by Hugues TR4 » 09 Apr 2015 15:52

Hi Phil,

I enclose the schematic for the 9EY3 changer, featuring the RP168.
Scan0001.jpg
(494.19 KiB) Downloaded 458 times

It is published in Phil Vourtsis'book..
All I did was make an extension directly from the muting switch, in parallel with the wires coming from the tonearm, going out through a female RCA plug fitted in the plinth.
All I get is a loud hum through the speaker...
If you have an idea...
Thanks in advance!

Cheers,

Hugh.

Coffee Phil
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Re: 1950's RCA 45 record player

Post by Coffee Phil » 10 Apr 2015 07:23

Hi Hugh,

I think this is do-able. While you have series string tube heaters and an off the mains power supply they somewhat isolated B- from the chassis and motor board with a capacitor. This makes it much less of a death trap. The motor is connected to the mains and is not involved in the B+ supply or tube heaters.

You mentioned a mute switch. Two of the schematics show mute switches. One has miniature tubes and a three pin connector on the tone arm wiring and the other has octal tubes and the arm is hard wired. Which is more like yours?

The schemos are for 120 Volt machines. Are you using one of these with a transformer or is there a 240 volt machine?

Phil
Hugues TR4 wrote:Hi Phil,

I enclose the schematic for the 9EY3 changer, featuring the RP168.
Scan0001.jpg

It is published in Phil Vourtsis'book..
All I did was make an extension directly from the muting switch, in parallel with the wires coming from the tonearm, going out through a female RCA plug fitted in the plinth.
All I get is a loud hum through the speaker...
If you have an idea...
Thanks in advance!

Cheers,

Hugh.

Hugues TR4
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Re: 1950's RCA 45 record player

Post by Hugues TR4 » 10 Apr 2015 09:25

Hi Phil,

Thanks for your message.
To answer your questions, my changer is the 9EY3, described on the middle scematic.
It has the round 3 contacts muting switch, to which I connected a single shielded wire with a female RCA at the end. Maybe I got the polarities wrong (?)
The machine is running on a 120/220V transformer: the speed (60 to 50Hz) is corrected, like my RP190, by a sleeve on the motor axle, and it is accurate as per my strobe disc.
Tried to find a cheap and lightweight transformer, couldn't get more than 60W max and it just melted after an hour playing time!
Now it runs on an old heavy and bulky transfo, without problems. Still have to investigate if I can find something smaller I could put inside the plinth, like the other one.
Still busy on a Dual 1219 at the moment (hum/tonearm wiring problems), which occupies my bench, but will re-open the RCA soon and check the muting switch connections.
Thanks a lot for any suggestion!

Cheers,

Hugh.

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Re: 1950's RCA 45 record player

Post by Coffee Phil » 10 Apr 2015 22:02

Hi Hugh,

I think I have most of this worked out in my mind. I am looking at the second schematic. There are a few things I need to confirm. That schematic is of the whole machine and the location of things is not all that clear. That seems to be the way it was done even in the '50s. Now the common practice would be to show the amplifier as a module, the speaker as a module and the turntable motorboard as an assembly. We still might have one schematic, but there would be boxes drawn around each assembly. The main area of confusion is some of the grounding. Note the use of two types of ground symbols. One is for the "common ground" or B-. This is connected to the mains and can shock you. The other ground is the "chassis" ground which is tied to B- with a reactance (C7) sufficiently high to protect you.

If we look at the area of the mechanism we see the motor coil connected to the amp via a two pin connector. One side is connected to the mains and the other to the "death ground". OK so far. Now move up right above the turntable platter to the tone arm wiring. Note the black wire connected to the "death ground" symbol. That can't be right. If you follow that black wire to the three pin connector you will see it connects to the amplifier chassis ground. I think the confusion is that on the motor board they used the same symbol used for "death ground" on the amplifier. I'm pretty sure the ground symbol on that black wire is the motor board. They should have used a third symbol and defined it. We need to confirm all of this as we don't want "death grounds" exposed.

I believe that you used a small autotransformer in your RP 190. We may be able to use a similar transformer here by putting the motor coil in series with the amplifier power input and using the transformer to just deal with the difference in current between the motor and amp.

Do you have polarized receptacles where you know which side is hot and which side is neutral. We do now but in the day of this player our receptacles were not polarized. Both pins on out plugs were the same. Now one pin is larger and the plug can only be inserted one way. Old plugs fit modern receptacles but typically not new plugs and old receptacles.

Phil


Hugues TR4 wrote:Hi Phil,

Thanks for your message.
To answer your questions, my changer is the 9EY3, described on the middle scematic.
It has the round 3 contacts muting switch, to which I connected a single shielded wire with a female RCA at the end. Maybe I got the polarities wrong (?)
The machine is running on a 120/220V transformer: the speed (60 to 50Hz) is corrected, like my RP190, by a sleeve on the motor axle, and it is accurate as per my strobe disc.
Tried to find a cheap and lightweight transformer, couldn't get more than 60W max and it just melted after an hour playing time!
Now it runs on an old heavy and bulky transfo, without problems. Still have to investigate if I can find something smaller I could put inside the plinth, like the other one.
Still busy on a Dual 1219 at the moment (hum/tonearm wiring problems), which occupies my bench, but will re-open the RCA soon and check the muting switch connections.
Thanks a lot for any suggestion!

Cheers,

Hugh.

Hugues TR4
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Re: 1950's RCA 45 record player

Post by Hugues TR4 » 12 Apr 2015 20:54

Hi Phil,

Thanks for the detailed lecture!
The best I can do now is open the little beast again as soon as I get time and try and play with the black ground wire which leads to the cart. Maybe also invert the wires from the cart (it's mono anyway.)
Gary VM said the black ground could be forgotten: I'll make a test without.
Will find out about the exact connections and let you know about the detailed current situation.
The TT plays fine, with a little hum from the amp, but nothing to worry about.
Have to live with a 66 years old machine which still sounds quite nicely for its age!
Will keep you informed about the actual situation.
Take care,

Hugh.

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Re: 1950's RCA 45 record player

Post by Big B5515 » 13 Apr 2015 06:00

[quote="Coffee Phil"]Hi Big B,

Congratulations on getting your RP 168 up and running again. It is looking good. I was intimidated by all the moving parts in that thing so I got the simpler RP 190. I seem to remember that since the RP 168 is blazing fast in changing records it requires a dashpot to damp the lowering of the arm. You might look at that to solve the arm bouncing issue.

Phil

Phil, I was unaware of any dashpot, at least there was none on the unit I have. I was thinking that there should be some kind of damping, and there was evidence of previous service or adjustments when I found it. I did not come across a manual or diagram for a 168 (didn't look too hard either) so left things pretty much as they were when I found it. Was a little concerned about the top of the changer spindle being warped and having a fingerprint etched into it, although I guess it could be carefully shaved down and repolished if I cannot find another. It seems that my unit had an extended stay in a hot attic due to this, and the warped and shrunken turntable mat (flattened and reused for now). Apologize for the late response as I've been busy with the RV and haven't turned on the computer lately. Also, ordered a 1942 edition of the radio physics book you recommended. Only a little over 100 pages in, but looks to be a well written reference to old school electronics (and a refresher on the basics). Thank you for your recommendation.


Hugh, The knob was on it when I found it. I suspected that it did not look right, but was unsure as I had never seen another of this model. It did have a bakelite stem behind it, which was in pieces (replaced this with a piece of hard plastic tubing). The only label on the bottom cover is the one with the model, serial #s and warranty info, ect (mostly intact). The label on the changer mechanism has a 3 digit code of 911 on the 3rd line though, if this is it.

Hugues TR4
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Re: 1950's RCA 45 record player

Post by Hugues TR4 » 13 Apr 2015 09:34

Hi Big B,
Do you have the complete service manual for the RP 168?
You can find it on the net at http://oldtech.net/TT.html.
Your changer must have been manufactured in the 11th week of 1949 (late march), it's quite an early model. Think the arm cueing damper only came out later that year. I have it on mine (ca june '49). If I open my changer again, I will try and make a picture.
You will have a rough idea about the look of the record change button when looking at the pic I sent on this thread earlier. It looks like a little piece of blind 6.5mm copper tubing. Do you still have the original reject lever mechanism inside? This copper button just pushes on the reject lever through a small spring.
There is also another, different service manual on the net: try googling "Manuals of 1950 most-often-needed radio diagrams". Think I found it there. The exploded view shows the damping system.
Try and get yourself Phil Vourtsis' book I mentioned before: it's a must for anyone who is interested in the RCA changers. Seen it advertized on e-bay some time ago.
Have lots of fun,

Cheers,

Hugh.

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Re: 1950's RCA 45 record player

Post by Coffee Phil » 13 Apr 2015 17:06

Hi Hugh,

Thanks for posting the link. I couldn't find it and I was about to fire up my old computer as I must have bookmarked it there. I looked at the RP 168 manual which you linked and could not find the damper. I must have seen it on one of Chris Cuff's U-tube videos. I seem to remember the damper came later to fix the tone arm bounce issue. Now that you say you have it I know I'm not hallucinating.

Phil


Hugues TR4 wrote:Hi Big B,
Do you have the complete service manual for the RP 168?
You can find it on the net at http://oldtech.net/TT.html.
Your changer must have been manufactured in the 11th week of 1949 (late march), it's quite an early model. Think the arm cueing damper only came out later that year. I have it on mine (ca june '49). If I open my changer again, I will try and make a picture.
You will have a rough idea about the look of the record change button when looking at the pic I sent on this thread earlier. It looks like a little piece of blind 6.5mm copper tubing. Do you still have the original reject lever mechanism inside? This copper button just pushes on the reject lever through a small spring.
There is also another, different service manual on the net: try googling "Manuals of 1950 most-often-needed radio diagrams". Think I found it there. The exploded view shows the damping system.
Try and get yourself Phil Vourtsis' book I mentioned before: it's a must for anyone who is interested in the RCA changers. Seen it advertized on e-bay some time ago.
Have lots of fun,

Cheers,

Hugh.

Hugues TR4
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Re: 1950's RCA 45 record player

Post by Hugues TR4 » 13 Apr 2015 20:05

Hi Phil,
You are perfectly sane in your mind!
The damper really existed.
If you Google "Manuals of most often needed radio diagrams" and you scroll to page 127 (RCA 9EY3), you will find another (later ) version of the service manual with a mention of the damper.
Think the damper only came out around june '49. My 168 has got it and it does make a difference.
This manual also gives you a few tips not present in the earlier edition (think it's dated 1950).
Will try and send a pic soon.
Hope this helps,

Cheers,

Hugh.

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Re: 1950's RCA 45 record player

Post by Hugues TR4 » 13 Apr 2015 20:30

P.S. The web address I mentioned also contains a full service manual on pages 133-144. Make sure you type " Manuals of 1950 most-often-needed radio diagrams".
It will lead you to a big book full of info you might find interesting!
You will find the damper on page 138 in the exploded view, #91.

Cheers,

Hugh.

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Re: 1950's RCA 45 record player

Post by Big B5515 » 15 Apr 2015 12:03

Appreciate the link to service manual. Most everything appears to be in proper order, but manual will help with fine tuning. The knob is simply mounted with a plastic stem and screw with a felt washer inside, and activates original lever. It would probably be easy enough to make something a little less conspicuous now that I know what it is supposed to look like.

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Re: 1950's RCA 45 record player

Post by Hugues TR4 » 03 Dec 2019 10:38

Hi All,

Reviving a (very) old thread!
I need your advice again. Found an ad on e-bay for a complete RCA 9EY3 refurbishing kit containing all the necessary caps and resistors.

https://www.befr.ebay.be/itm/RCA-45-MOD ... 1438.l2649

Thought I could have a try at it...
Question: would it be worth buying and really make a big difference? And wouldn't it be too difficult for a not too good electr(on)ician like me?

Both my RP190 and 168 are working fine (currently listening to a stack of old 45's on the 190 through my main chain), but I tend to become fussier after working on top idler Dual's (1219 and 1229), and I wonder if I could improve the sound of my 168.
Your usual kind cooperation will be most appreciated!
Cheers,

Hugh

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Re: 1950's RCA 45 record player

Post by Coffee Phil » 04 Dec 2019 21:21

Hi Hugh,

Good to hear from you.

That kit strikes me as spendy for what you are getting, but he is adding value by making a kit. He is giving you a manual and marking the parts with the reference designators. I'm thinking you can get all the parts from Digi-Key or Mouser for ~ $20 to $30 USD. If you already have the schematic and are willing to put in a bit of effort on their websites you can save a bit of money. On the other hand his effort may be worth the extra $20 to $30. If duty is not too bad it may be worth it, but if duty is outrageous I think Mouser has a Europe office and you may may be able to circumvent that.

I have no doubt that you can pull this off after your RP 190 and RP 168 restorations. Make sure you have a good soldering iron, solder sucker, decent long nose pliers, wire cutters, and of course non acid core solder.

Keep us updated on the progress.

Phil


Hugues TR4 wrote:
03 Dec 2019 10:38
Hi All,

Reviving a (very) old thread!
I need your advice again. Found an ad on e-bay for a complete RCA 9EY3 refurbishing kit containing all the necessary caps and resistors.

https://www.befr.ebay.be/itm/RCA-45-MOD ... 1438.l2649

Thought I could have a try at it...
Question: would it be worth buying and really make a big difference? And wouldn't it be too difficult for a not too good electr(on)ician like me?

Both my RP190 and 168 are working fine (currently listening to a stack of old 45's on the 190 through my main chain), but I tend to become fussier after working on top idler Dual's (1219 and 1229), and I wonder if I could improve the sound of my 168.
Your usual kind cooperation will be most appreciated!
Cheers,

Hugh