• Get involved.
    We want your input!
    Apply for Membership and join the conversations about everything related to broadcasting.

    After we receive your registration, a moderator will review it. After your registration is approved, you will be permitted to post.
    If you use a disposable or false email address, your registration will be rejected.

    After your membership is approved, please take a minute to tell us a little bit about yourself.
    https://www.radiodiscussions.com/forums/introduce-yourself.1088/

    Thanks in advance and have fun!
    RadioDiscussions Administrators

Harris CB 1201 Turntable issues

S

SFM-Ptgal

Well, I've powered the tt on, and got impressed by the startup speed... cooool...
Tryed to stop the platter while running and the beast was strong...
A minute later I started to see a little smoke coming from underneath. I imediatally stoped the turntable.
It seems that a component that looks like a disc capacitor from the start-stop switch has burned a little.
Here is the picture:

http://i215.photobucket.com/albums/cc118/SFM-PTGAL/TTswitch.jpg

I've turned the TT on again and seems that the switch is in by-pass. No matter the position, the pilot light turns on and the motor starts spinning right upon mains connection. And the motor gets HOT HOT HOT!!!! :-[

The turntable was on the shelf for a few years, in a sort of a barn. But still clean.

What might be causing this issues ? Simply the look a like capacitor? What is it's value?

Any help appreciated!

Pedro
 
That is a MOV (Metal Oxide Varistor) normally used for overvoltage protection. That is the first time I've seen it used to protect switch contacts. You can replace it with a 0.01 uF / 1kV ceramic disc capacitor. As for the motor getting hot, that may be due to the partially shorted varistor not supplying enough voltage to the motor when the switch is off.
 
After replacing the bad part, also be sure that any bearings etc, are properly lubed and cleaned. I'm not familiar with that turntable, but under-lubed motors/bearings, etc can cause a motor to overheat. All of that should probably be completely dissassembled and everything cleaned and re-lubed. Old lube/grease can be pretty stiff stuff.

df



SFM-Ptgal said:
Well, I've powered the tt on, and got impressed by the startup speed... cooool...
Tryed to stop the platter while running and the beast was strong...
A minute later I started to see a little smoke coming from underneath. I imediatally stoped the turntable.
It seems that a component that looks like a disc capacitor from the start-stop switch has burned a little.
Here is the picture:

http://i215.photobucket.com/albums/cc118/SFM-PTGAL/TTswitch.jpg

I've turned the TT on again and seems that the switch is in by-pass. No matter the position, the pilot light turns on and the motor starts spinning right upon mains connection. And the motor gets HOT HOT HOT!!!! :-[

The turntable was on the shelf for a few years, in a sort of a barn. But still clean.

What might be causing this issues ? Simply the look a like capacitor? What is it's value?

Any help appreciated!

Pedro
Click to expand...
 
That part is an MOV. They will go bad sometimes but most times they burn due to high voltage. That one is rated at 150 volts. Check your line voltage and be sure you dont have it wired into 220-240 volts. High voltage can also be the reason the motor runs hot.
This would be very unusual but I have seen it happen.

Good Luck
 
rew said:
That part is an MOV. They will go bad sometimes but most times they burn due to high voltage. That one is rated at 150 volts. Check your line voltage and be sure you dont have it wired into 220-240 volts. High voltage can also be the reason the motor runs hot.
This would be very unusual but I have seen it happen.

Good Luck
Click to expand...

JC!!!! You're right!!!! It's a 115v motor!!!! I noticed that right now on the motor tag. I didn't see the voltage rate correctly. I was induced in error by seeing the frequency rate: 50hz. From that frequency I assumed that it was a 220v motor! :eek:

Thank you guys for opening my eyes!

By the way... what MOV should I ask for at the Radioshak? (As if there was one in Portugal ;D)
 
SFM-Ptgal said:
rew said:
That part is an MOV. They will go bad sometimes but most times they burn due to high voltage. That one is rated at 150 volts. Check your line voltage and be sure you dont have it wired into 220-240 volts. High voltage can also be the reason the motor runs hot.
This would be very unusual but I have seen it happen.

Good Luck
Click to expand...

JC!!!! You're right!!!! It's a 115v motor!!!! I noticed that right now on the motor tag. I didn't see the voltage rate correctly. I was induced in error by seeing the frequency rate: 50hz. From that frequency I assumed that it was a 220v motor! :eek:

Thank you guys for opening my eyes!

By the way... what MOV should I ask for at the Radioshak? (As if there was one in Portugal ;D)
Click to expand...




Good luck at Radio shack, it's not like the old days. here in the states you have to be very lucky to get a capacitor or a freakin' resistor of the shelves in the store.nevermine asking for a MOV. The sales person will stear at you in the face like, if you have two haeds and say whats a MOV. good luck.

I would check on the internet first.
 
SFM-Ptgal said:
JC!!!! You're right!!!! It's a 115v motor!!!! I noticed that right now on the motor tag. I didn't see the voltage rate correctly. I was induced in error by seeing the frequency rate: 50hz. From that frequency I assumed that it was a 220v motor! :eek:
Click to expand...

Ahh yes, "assumption is the mother of all %@#&ups". Reminds me of that poster hanging on the wall in high school, which simply said "Assume Nothing".

Sorry you had to learn that the hard way.

R
 
I've replaced the MOV with a 135V one (the was no other available). The turntable motor is now running on 110v/50hz as fresh as possible, just a little warm but nothing much.

Now another possible issue: I've made a strobe print from the internet, an placed it on the platter and none of the speeds seemed correct from looking to the strobe. I don't have a needle on the tonearm to confirm the problem (listen) or perhaps it's just a misprinting of the strobe.

If the problem is from the motor speed adjustement is there a way to correct it? I've seen somewhere in the forum that was possible to adjust the speed on DD-AC idler wheel turntable motors. Will I be able to do the same if needed?
 
If you are on 50Hz, your light speed is that also. If the strobe disc is designed for 60Hz, therein lies your problem...Check...JBI
 
Assuming this turntable uses a synchronous motor then the speed is determined by the number of poles and the line frequency. A motor designed for 60 cycles ain't gonna work on 50 cycles.
 
Radioceo said:
Assuming this turntable uses a synchronous motor then the speed is determined by the number of poles and the line frequency. A motor designed for 60 cycles ain't gonna work on 50 cycles.
Click to expand...

The motor tag shows 110v/50 hz, so it's a 50hz motor running on a 50hz frequency... I'lll check it again with a 60hz strobe, just in case...
 
Just a quick report to say that the Turntable is in a great condition. No speed issues noticed at all.
Yesterday I've put it in to a test... I forgot to turn the motor off when I went shopping. It runned for 2 hours... only a slight smell of warm oil noticed ;D and the speed was steady.

Pedro
 
Can't find a needle

I can't find a needle or any results for this turntable at all.. I have this same Harris cb1201 table and on the Internet as far as parts are concerned it's like they never existed.. Anyone know where I can get a cartridge or needle or something so this thing will work??
 
Status
This thread has been closed due to inactivity. You can create a new thread to discuss this topic.


Back
Top Bottom