Author Topic: RCA 45 record player  (Read 1798 times)

Magnavoxland

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Re: RCA 45 record player
« Reply #15 on: April 09, 2018, 06:31:56 PM »
Frankly I am stumped as to what to do.  I hate finding stuff that is jury rigged or modded like this. 

I just restored a stereo RCA amp that had some replacement parts installed that was real shoddy work.  An electrolytic lug had been cut off and was just pulled up and suspended in mid-air and two crazy radial electrolytics were attached...one looked like an AA battery...real long and skinny.  Two other wax capacitors were replaced with two capacitors in series as the person didn't have the right value.  I had to straighten all that mess out and do it right.

As I said earlier, I would probably test it initially with the oddball electrolytic in place.  If it causes any issues such as hum or motorboating, I would cut it out where it goes to.

electra225

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Re: RCA 45 record player
« Reply #16 on: April 09, 2018, 07:13:14 PM »
Nichicon PZ series electrolytic caps are about the size of an AA battery.  I like using them when I restuff a three-part electrolytic cap can.  I understand what you're saying about modded amplifiers.  I really don't believe Bill has a problem with his amp.  The worst that can happen is he'll have to remove the extra cap and put everything back like the schematic shows.  Then if he has a problem, he can troubleshoot from that point.  At least he'll have a baseline to start from.



I don't like hooking caps together to get the correct value.  That is the ultimate hack kluge.  The experts on that other forum seem to believe that is a good practice on a buffer cap.
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Bill

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Re: RCA 45 record player
« Reply #17 on: April 09, 2018, 09:32:25 PM »
Thanks everybody.  The cartridge that I ordered from Gary at VM arrived today so I have everything I need to make this thing go.....I hope!  I think I might do like Larry suggested and leave the 470 in place and see what happens.  Then I might just unsolder one lead and see what it does.  I can always hook it back up or unsolder the other lead if there is no change.  It's not like it's a hi-end unit, it's just something I had when I was a kid and when I ran across it, it was cheap, I could not say no. :)  There is always room for one more....right?

Larry do you usually leave the silicon rectifier in place if it's working ok?  Or do you replace them automatically? 

Thanks again,

Bill

Magnavoxland

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Re: RCA 45 record player
« Reply #18 on: April 09, 2018, 11:06:35 PM »
I went through several years of always replacing the selenium rectifier with a diode.  But the last year or so I've been leaving them alone as long as the amp sounds good and the rectifier isn't smoking.......

The reason it really doesn't hurt to leave them alone is if one shorts all it will do is take out that 47 ohm resistor.  Seleniums are never used in higher quality transformer operated sets...only in the cheapest amplifiers....like this little two tuber...

TC Chris

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Re: RCA 45 record player
« Reply #19 on: April 09, 2018, 11:13:27 PM »
Selenium rectifiers do make me nervous,even though I don't always replace them right away.  I had a nice Zenith G 725 on my desk at my office. I went out to run an errand and while I was gone the rectifier incinerated itself.  The smell was dramatic, according to onlookers, but the real problem was that the rectifier on that set is right under the speaker.  The speaker cone burned up too.  So  my advice is that if your device is going to see regular use, replace the rectifier.

Chris Campbell

electra225

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Re: RCA 45 record player
« Reply #20 on: April 10, 2018, 12:03:18 AM »
I have a chassis for a Zenith 725.  I got it in a box of junk and have never tried to see if it works.  It still has its speaker and selenium rectifier.  It is in good enough shape I just never tossed it.  And it has Zenith tubes.
I don't need Google.  My wife says she knows everything.

Bill

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Re: RCA 45 record player
« Reply #21 on: April 10, 2018, 09:49:45 AM »
First I just realized I have been saying or spelling selenium wrong.  For some reason, senior moment I guess, I used the word silicon.  :-[  Sorry!

This little 45 won't be a daily driver but down the road I probably will replace the selenium rectifier, just because.  Right now I just want to get it going and see what it sounds like.  With only a 4 inch speaker I'm not expecting much.

Bill

electra225

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Re: RCA 45 record player
« Reply #22 on: April 10, 2018, 11:50:30 AM »

Senior moments during our advancing years can be expected.  I speak from experience.   ;)
You might be surprised how good that little player will sound with a four inch speaker.  It has a tone control and two stages of audio. 
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Bill

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Re: RCA 45 record player
« Reply #23 on: April 10, 2018, 02:02:33 PM »
Well...........the little 45 is up and running.  It sounds the best at about 1/2 volume, over that it gets distorted.  I also need to say it's a little garbled at any volume.  Not as clear as I would think it should be.  Not sure where that is coming from, maybe just a cheap amp.  I also did the experiment.  I left the 470 wired in for the first try and everything was ok except what I mentioned above.  Disconnecting one wire on the 470 produced a hum.  :(  You could still hear music ok, best at 1/2 volume and still a little garbled.  So I guess someone installed the 470 for a reason but I wonder what is causing the hum?   I'm sure that was not a factory option.  ;)  All the caps are replaced, both kinds. Resistors are still all original.  If a tech installed the 470 I would presume that he could not solve the hum problem?  Thoughts?

Bill

electra225

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Re: RCA 45 record player
« Reply #24 on: April 10, 2018, 04:04:56 PM »
That little player basically has the audio stage and speaker that you would find in an AA5 radio.  Have you tested and/or subbed the tubes?  You could have grid emissions or gas in those.  Or a heater to cathode short, although that is more associated with hum than distortion.  You could try subbing the speaker.  The voice coil could be rubbing a bit, which will sound worse the higher the volume gets.  I'm betting your inherited the hum.  Check the ground on the shield around the cartridge wires.  Run a redundant ground from changer to amp and see if the hum goes away with the extra cap connected then disconnected.  Do you have a signal tracer?  You could short the grid in the first audio tube to see if the hum disappears.  Is the hum affected by the volume control?
I don't need Google.  My wife says she knows everything.

Bill

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Re: RCA 45 record player
« Reply #25 on: April 10, 2018, 04:36:43 PM »
Tubes have been tested but not subbed.  I'm going to test them again incase I missed something. But before I do that I need to point out something that I discovered after finally getting the schematic to print.  It wanted to print huge and leave both sided off the paper.  Before I was referring to the computer screen and trying to double check things.  With that being said.....would you please pull up Larry's thread where he had the attachment showing the schematic.  Please notice the four different model numbers listed with the letters A,B,D,E after each one.  Notice we have been looking at RS-152B.  Please notice what it says for each chassis number especially RS-152E.   :-[  ::)  :'(  ;D

I feel so dumb!!!!!!!

Unfortunately my chassis number has been rubbed off at some point.  There is this other number that I can read which is RVG2747-15.  Not sure what that means but I'm sure something!  So without my chassis number it's either going to be RS-152D with the 470mmf added for some reason or a RS152E which would be correct.  Back to the drawing board to see what R9 is and R2 depending on D or E chassis.  The fun never stops!

Bill


electra225

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Re: RCA 45 record player
« Reply #26 on: April 10, 2018, 06:55:32 PM »
Don't fall on your sword just yet.  You may not have the "E" chassis.  Even if you do, C7 is listed at 470pf.  The one you have is 470 mic, which is like a million times larger.  Look to see if your chassis has the updates listed for an "E" chassis.  IF not, you probably have everything you need already.  If the hum is affected by the volume control, all that is ahead of the volume control is the pickup and its associated wiring.  Perhaps the ground on the shield for the cartrige wires is not good.  I had one of those drive me up a wall on a Philco one time.  They can look good, test good, but not BE good.  Run a redundant ground from changer to amp and see if the hum disappears.


Grid emission may not be detected by a tube tester.  It only happens when the tube gets screeching hot.  Substitution with a known good tube is the only way to detect grid emissions that I know of.  If the audio gets gradually worse as the set warms up, you can reasonably suspect grid emission.  A gassy tube typically sounds bad all the time depending on how bad it is.


There is no parts list posted.  Do you have one?
I don't need Google.  My wife says she knows everything.

Bill

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Re: RCA 45 record player
« Reply #27 on: April 10, 2018, 07:44:59 PM »
My next step is to check the R2 and R9 per E chassis and see what's there.  I'm wondering if a tech read it wrong and just put in the wrong capacitor?  The new cartridge from Gary at VM included a new wire harness.  No separate ground and the instructions said ground not needed.  Body of cartridge is plastic, old one was metal. I will use a jumper and try the ground thing.  I did not pay any attention with volume and how it affects the hum. 

I do not have a parts list.

I do not have tubes to sub.

Bill

Magnavoxland

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Re: RCA 45 record player
« Reply #28 on: April 10, 2018, 11:49:11 PM »
274 is the number to identify the set as an RCA.  All RCA amplifiers, and changers, are stamped with a 274 number.

Electra225, there is no tone control on an EY3...just a volume control.

Bill

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Re: RCA 45 record player
« Reply #29 on: April 11, 2018, 07:43:13 AM »
Larry, thanks for the help with the 274 number.  If you are referring to my EY-3 to Electra 225, I have a tone control.

Thanks,
Bill