Need help with Rek-O-Kut Rodine Jr Wiring Setup

[Lrstevens]

Good Heaven's that is an absolute treasure trove of useful tubes.

Have you checked for blown fuses, or even that the power plugs are still plugged in? Now if you do start it, you must make sure the speakers are connected. Turning on a tube amp without the speakers connected can do enormous damage and fast.

Thanks for that bit of advice regarding needing speakers attached to a tube amp when powering on. When I initially turned on the amp one of the speakers was not connected. Hopefully no damage ensued, but the amp itself didn't appear to have any power as none of its tubes lit up. Since there was no sign of life in any of the components, I disconnected the amp from power. The tuners and multiplex AC cords were connected to the tube amp.

See my 1/7/24 @ 5:07pm reply to "highfigh" regarding my earlier diagnosis today. In a nutshell today I unplugged the tuner and multiplex from the tube amp and connected them directly to AC. I found the tuner and multiplex themselves now received power (lit tubes and a multiplex beacon light lit). The tube amp was apparently supplying AC power to the tuner and multiplex through the tube amps switched outlets. Conclusion: Since the tube amp wasn't showing any signs of power, neither were the tuner and multiplex. I so far determined the tube amp was the root cause of no power to the tuner and multiplex. That does not mean however that there still may not be anything wrong with either of them but a step in the right direction.

Will report back regarding whether I find a blown fuse - should have been something I checked first. Thanks to you gents, "TLS Guy" and "highfigh" I'm learning a bit more each day!

 

[highfigh]

highfigh, you mentioned, "Don't let the motor try to start if it doesn't want to- that could damage the winding."
Today I went to see if the turn table would work from the get-go since it did work the other day. Unfortunately, when I set the Rek-O-Kut to 33 1/4 it started to turn about 1 revolution per minute as before. I recalled what you wrote earlier about damaging the winding. Would you happen to know what could be the cause of the motor not coming up to speed? I'm assuming the motor itself is good, but something else is causing its delay?

Seeing that both the Tuner and Multiplex AC plugs were connected to the Control Amp I surmised the connector may be Switched and the main problem was the Control Amp. Through process of elimination, I connected the Tuner & Multiplex AC plugs directly to AC. The AM/FM Tuner Face and other tubes show power. The Multiplex does not display the Power light but its Beacon does come on for a bit and turns off. If I unplug and replug the Beacon will display and turn off. I didn't look at the tubes of the Multiplex because I had my other equipment on top of its compartment. With that said I believe I may have possibly eliminated 33% of my problem with the Fisher gear. I see what appears to be a huge transformer on the Control Amp chassis which could possibly be the problem.

I hadn't looked closely at the shot from below and thought that it might be direct drive. This turntable uses idler wheels to drive the platter, as shown in the photo- the surface of the rubber becomes hard over time and that prevents it grabbing the drive spindle and platter, so I suspect the spindle is slipping, which would definitely prevent the platter starting quickly.

Rotate the platter with your hand- does it spin easily, or do you feel resistance? If you feel resistance, remove the rubber mat from the top of the platter and look for a way to grasp it, in order to lift it off- the hole near the upper right in the photo (with three screws) is where the post on the platter fits and it should come out easily enough. You may need to rotate the platter as you lift it and once it's out, you can clean and lube the post and bushing to make it ready for new lubrication. Vaseline may seem like a good option, but it hardens over time, so white Lithium grease is a better choice- you should be able to find a small tube at an auto parts store.

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Check out the rest of the article-

Listening #120 | Stereophile.com

1) The Rek-O-Kut Rondine Jr.'s first day home. For the qualities I most value in a music system—impact, substance, texture, color, and, above all, the ability to play lines of notes with a realistic sense of momentum and flow—the venerable Garrard 301 and similar well-made turntables with...

www.stereophile.com

 

[Eppie]

You can run that gear for short periods of time for testing but I would not leave it on for any length of time without servicing. Equipment of that age is very likely to have some leaky capacitors which can burn out the tubes over time. It is common in tube amplifier repair to check for capacitor leakage and replace those first. The wax paper cylindrical caps are the worst offenders and the metal cans can go too. The mica caps are less often an issue but I've seen them fail on occasion. The resistors should all be checked as well. You can measure in circuit for anything obvious but may have to unsolder one end if in doubt. Looks like it could be an interesting restoration project.

 

[highfigh]

You can run that gear for short periods of time for testing but I would not leave it on for any length of time without servicing. Equipment of that age is very likely to have some leaky capacitors which can burn out the tubes over time. It is common in tube amplifier repair to check for capacitor leakage and replace those first. The wax paper cylindrical caps are the worst offenders and the metal cans can go too. The mica caps are less often an issue but I've seen them fail on occasion. The resistors should all be checked as well. You can measure in circuit for anything obvious but may have to unsolder one end if in doubt. Looks like it could be an interesting restoration project.

A lot of the caps and resistors can be measured in-circuit after removing the tubes because at that point, they're dead-ended.

 

[highfigh]

Thanks for that bit of advice regarding needing speakers attached to a tube amp when powering on. When I initially turned on the amp one of the speakers was not connected. Hopefully no damage ensued, but the amp itself didn't appear to have any power as none of its tubes lit up. Since there was no sign of life in any of the components, I disconnected the amp from power. The tuners and multiplex AC cords were connected to the tube amp.

See my 1/7/24 @ 5:07pm reply to "highfigh" regarding my earlier diagnosis today. In a nutshell today I unplugged the tuner and multiplex from the tube amp and connected them directly to AC. I found the tuner and multiplex themselves now received power (lit tubes and a multiplex beacon light lit). The tube amp was apparently supplying AC power to the tuner and multiplex through the tube amps switched outlets. Conclusion: Since the tube amp wasn't showing any signs of power, neither were the tuner and multiplex. I so far determined the tube amp was the root cause of no power to the tuner and multiplex. That does not mean however that there still may not be anything wrong with either of them but a step in the right direction.

Will report back regarding whether I find a blown fuse - should have been something I checked first. Thanks to you gents, "TKS Guy" and "highfigh" I'm learning a bit more each day!

As TLS mentioned, turning this on/off without speaker load can cause damage- having speaker or resistors as a load prevents instant discharge in the output transformer, which often causes short-circuits. The one way to turn it on/off without damaging the transformer involves using a VariAc, starting at 0 V and increasing to 110V (likely the voltage shown on any schematics or other diagrams for this age of equipment) and lowering it to 0V before turning it off.

BTW- tube electronics use high DC voltage- if you press the power switch, don't touch anything inside with your bare hand or with anything that can conduct electricity. A common practice is to use a clean, dry bamboo chopstick (or plastic) but that's only for poking parts and circuit boards, as a way to find loose connections. NEVER touch the metal chassis if you're close to any live circuitry inside- put the free hand in your pocket.

 

[Eppie]

Looks like it has one of those magic eye tuners. I hope that tube is still good. Those can be hard to find.

 

[highfigh]

Looks like it has one of those magic eye turners. I hope that tube is still good. Those can be hard to find.

The kind that has a line to show tuning are hard to find but the green eye are all over in the antique radio sites and forums.

 

[Eppie]

The kind that has a line to show tuning are hard to find but the green eye are all over in the antique radio sites and forums.

That's good to know. Watched another restoration by Mr Carlson and he stressed again about not turning on old tube radios without checking the caps for DC leakage first. There should at least be some current limiting device in line, like a dim bulb limiter which is easy to build. I have incandescent bulbs set aside for that purpose as they are disappearing off of store shelves.

 

[highfigh]

That's good to know. Watched another restoration by Mr Carlson and he stressed again about not turning on old tube radios without checking the caps for DC leakage first. There should at least be some current limiting device in line, like a dim bulb limiter which is easy to build. I have incandescent bulbs set aside for that purpose as they are disappearing off of store shelves.

I recently bought a high wattage bulb at Home Depot, but I still have some smaller ones, in the 40W-60W range. The big one in my tester drops the line voltage to 110VAC, which is the original spec for the amp I was servicing and since that's collectible, I didn't want to damage it.

If you watched one of Tim Allen's shows (IIRC, it was 'Home Improvement'), you might remember the episode where he wanted 75W bulbs, but they had been banned, so he found a source and the sale was like a back alley drug deal.

 

[Lrstevens]

Thanks for that bit of advice regarding needing speakers attached to a tube amp when powering on. When I initially turned on the amp one of the speakers was not connected. Hopefully no damage ensued, but the amp itself didn't appear to have any power as none of its tubes lit up. Since there was no sign of life in any of the components, I disconnected the amp from power. The tuners and multiplex AC cords were connected to the tube amp.

See my 1/7/24 @ 5:07pm reply to "highfigh" regarding my earlier diagnosis today. In a nutshell today I unplugged the tuner and multiplex from the tube amp and connected them directly to AC. I found the tuner and multiplex themselves now received power (lit tubes and a multiplex beacon light lit). The tube amp was apparently supplying AC power to the tuner and multiplex through the tube amps switched outlets. Conclusion: Since the tube amp wasn't showing any signs of power, neither were the tuner and multiplex. I so far determined the tube amp was the root cause of no power to the tuner and multiplex. That does not mean however that there still may not be anything wrong with either of them but a step in the right direction.

Will report back regarding whether I find a blown fuse - should have been something I checked first. Thanks to you gents, "TLS Guy" and "highfigh" I'm learning a bit more each day!

I checked the Control Amp fuse and it is fine. There are (4) 7189 tubes along the rear of the amp. I don't know what a possible blown tube looks like. Do these tubes look OK or one can't tell a bad tube just by looking at it?

I found two places for a 7189 fuse (see link below). Any brand preference? Any other vendors?

The Tube Store - Preferred Series 7189 (EL84) Tubes - www.thetubestore.com
Tube Depot - Tung-Sol 7189 New Production Power Vacuum Tube | TubeDepot.com

 

[TLS Guy]

I checked the Control Amp fuse and it is fine. There are (4) 7189 tubes along the rear of the amp. I don't know what a possible blown tube looks like. Do these tubes look OK or one can't tell a bad tube just by looking at it?

I found two places for a 7189 fuse (see link below). Any brand preference? Any other vendors?

The Tube Store - Preferred Series 7189 (EL84) Tubes - www.thetubestore.com
Tube Depot - Tung-Sol 7189 New Production Power Vacuum Tube | TubeDepot.com

You can't usually see a bad tube by looking at it. But a bad tube will not usually stop an amp powering up, but it can stop it working and often does.

You are not experienced in these matters, so you are going to need professional help from someone with experience in tube equipment and who has the right test equipment.

You will do much more harm than good if you try and fix this. Also working on tube equipment is very dangerous as there are often voltages in excess of 300 volts. The tubs amps I used in years past had HT voltage of 350 volts.

 

[Lrstevens]

You can't usually see a bad tube by looking at it. But a bad tube will not usually stop an amp powering up, but it can stop it working and often does.

You are not experienced in these matters, so you are going to need professional help from someone with experience in tube equipment and who has the right test equipment.

You will do much more harm than good if you try and fix this. Also working on tube equipment is very dangerous as there are often voltages in excess of 300 volts. The tubs amps I used in years past had HT voltage of 350 volts.

Thank You TLS for the warning - I will heed your caution. Through 6 degrees of separation, I was able to come in contact with my brother's friend's uncle who has experience working on tube amps. I spoke to him today and he said to bring him all 3 components and whatever schematics I had or he could look them up and get the system working. I was luckily able to find all the Service Manuals online and will take them to get at the necessary schematics and parts descriptions enlarged and laminated.