How to clean a tuner (analog)

[KrisM]

Great info!
I picked up a Kenwood KT615 awhile ago, and would like to use it to record a favorite blues program every week, but while testing it out I noticed that sometimes there is no sound coming out of the rca's. The signal meters still show reception, but zero sound. A very slight tap on the tuning knob gets the sound back. Could this be a cleaning issue or something else? It looks quite clean inside.

Thanks for any help!

 

[Oerets]

Does it have a muting switch if so turn it off and see if that helps . Work the switch a few times it might be dirty .

If you haven't used canned air on the fins yet it could help also .



Barney

 

[KrisM]

Thanks for the tip.
I've never really worked on a tuner before, so I guess I need to get in there and start cleaning(carefully). I've been using the tuner section of a Marantz 2226 to record the blues show, but I figure the Kenwood will do a better job. I'm kind of a tuner dummy, I'm just starting to appreciate what a good tuner can do.

 

[larryderouin]

Sounds like the connection between the shaft bearings, and the clips is intermittent.

Use CRC QD ELECTRONICS CLEANER on the FINS. This is NON RESIDUE. Then...........
Very Carefully put a drop of Deoxit on each of the SHAFT BEARING CLIPS. Then cycle the Tuner back and forth a few times to get the DeOxit into the bearings, and connecting clips.

let it sit for a 1/2 hour or so. Cycle the tuner again about 20 times. Then turn it on, and tune it in. If the knob is separate from the tuner gang, then clean any switches that are immediately adjacent to it.

Larry

 

[johnny ro]

just did it.

Picked up a Sansui 6060 receiver two weekends ago for $10 at yard sale in Madison NH. Dirty control pots, pretty clean otherwise. D5 worked on the volume and tone pots and the switches too.

Read this post today and cleaned tuner cap shaft and followers. Thought it needed alignment but this cleaning procedure brought it back nicely.

Used brake parts cleaner, says zero residue on it, which is needed for disc brake surfaces. Used compressed air to dry the cleaner.

I don't have syringe. I used small awl as delivery machine for D5.

Squirt D5 into upside down cap, dip into it with awl, then touch awl to axle where the followers ride. About 5 dips to make it look wet = one half a small drop.

Tuner now picks up all the stations out there, and no more noise when turning dial.

Thanks Dr*audio

 

[DR_Simpkins]

This ground cleaning worked great for a tuner that drifted, and would just cut out often. Problem solved. For those like me who want to clean it 'right now' rather than waiting for an internet order, Home Depot sells CRC Electrical Grade QD Contact Cleaner, non-residue ($6-ish/11 oz)

So does Autozone or any other auto parts place. CRC is a quality brand.

 

[KrisM]

I've got some Lloyds Keens-It electrical contact cleaner. It says, "Instantly cleans, flushes and degreases, non conductive, non flammable, dries quickly leaving no residue".
Is this OK to use?

Thanks!

 

[Oerets]

I've got some Lloyds Keens-It electrical contact cleaner. It says, "Instantly cleans, flushes and degreases, non conductive, non flammable, dries quickly leaving no residue".
Is this OK to use?

Thanks!

Is it " plastic safe " or at least states " safe on most plastics " . I've never used that brand so have no experience with it .



Barney

 

[KrisM]

It says safe on plastics, except styrene.

 

[Tripod]

Hi Dr*Audio

Thanks for the great tips. I have recently acquired a Sansui 350 receiver and despite its awful looks inside, now works well except for one vexing problem.

I first list the work done during the past two weeks and then I'll get to the point of the problem.

Repairs: Cleaned the massively dirty and dusty casework, cleaned the dial inside and out, replaced foam strips around the dial as the originals turned to dust, replaced snipped off power cord, cleaned all rca jacks and speaker terminals, replaced all illumination bulbs and cleaned their sockets - (all were blown when I acquired the receiver), repaired broken tuner flywheel, vacuuumed out massive amounts of dust everywhere inside, replaced all fuses with correct value items, cleaned the volume potentiometer with both contact cleaner and silicone free WD-40 type lubricant. Also cleaned all other controls and switches using contact cleaner and WD 40 silicone free. Vacuumed and used compressed air to remove all excess cleaning and lubricating chemicals.

When all of the above was done, I connected the equipment for a duration of 8 hours to our 220V 50Hz mains through a 100W lightbulb and fitted loading resistors at the speaker terminals prior to doing this.

As yet, I have not touched the tuning capacitor other than vacuuming it and using compressed air.

Now the problem: Everything now works correctly, tuning is fine and there are no crackling during function changing except for an intermittent soft crackling sound at low volume at about 1 or 2 minute intervals. At mid and higher listening levels, the crackling or rustling sound through the speakers go away completely.

Last night, I also tried the phono function and this function produces the same symptom - intermittent soft crackling at low volume.

Do you think there could still be residue muck inside the volume pot? On powering down, I usually also turn the volume down to zero. As the equipment powers down and I turn the volume to zero, I can also hear a slight crackle through the speakers.

What do you think could be the problem? - Intermittent soft crackling at low volume?

The pics show the equipment prior to cleaning and all is sparkling clean now except for the spotty chassis.

Thank you for your time.

tripod

 

[KrisM]

I did a cleaning and the problem returned after a couple of minutes.:tears: I also did a Dexoit on the swiches for what it's worth. Maybe they need some more cleaning. I guess I'll need to keep trouble shooting this thing. The good news is the case is HUGE, so there's a lot of room inside to see what is going on.
And for the record the Lloyds stuff didn't damage any plastic, but I wouldn't recommend it. It sprays way too much cleaner. I'd guess 4 times what a can of Deoxit sprays on the high setting.

Thanks for the help.

 

[terra1]

- intermittent soft crackling at low volume.

Assuming thorough cleaning was done and crackling occurs when controls are set and not just when turning controls: Have you checked the DC offset? See the DC offset thread in Vintage Solid State. Do you have the service manual? Then check if there is a section on amplifier adjustments.

 

[Tripod]

Assuming thorough cleaning was done and crackling occurs when controls are set and not just when turning controls: Have you checked the DC offset? See the DC offset thread in Vintage Solid State. Do you have the service manual? Then check if there is a section on amplifier adjustments.

Hi terra1

Thanks for the recommendation. None of the controls are noisy when I'm using them, except for the volume pot when powering down and when I turn the volume to zero during powering down.

There are still components requiring some more cleaning and I'll get to them as soon as I have a chance.

No service manual. I will check out the dc offset thread now, thanks.

Cheers

tripod

 

[terra1]

Hi terra1

Thanks for the recommendation. None of the controls are noisy when I'm using them, except for the volume pot when powering down and when I turn the volume to zero during powering down.

There are still components requiring some more cleaning and I'll get to them as soon as I have a chance.

No service manual. I will check out the dc offset thread now, thanks.

Cheers

tripod

Checking DC is more or less to see if there are any signs of obvious problems.

Here's another recent similar thread but they are getting a hissing sound
http://www.audiokarma.org/forums/showthread.php?p=3993336#post3993336
I noticed Dr*audio responded to that and hopefully he will check in here too.

The reason I mentioned DC and bias is that I had a receiver that crackled at low volumes and also was getting hot in one channel. Adjusting the bias cured both situations. Beyond that others may have to help you with troubleshooting output transistors or whatever.

 

[dr*audio]

As I recall, this receiver has no speaker relay, so when you turn it on and off there is nothing to prevent odd sounds coming from the speakers, which normally occurs when circuits power up or down. So that part is normal, but you should not have noise with the volume in any position under normal operating conditions. I agree the first place to check is DC voltage where is is not supposed to be. I don't think the 350 has a DC offset adjustment, but I don't think the problem is in that part of the circuit anyway. I think you have a leaky cap either before or after the volume control. Using a DMM, check on all terminals of the volume control for DC voltage, with no signal. Check with the control at minimum and maximum. It should read 0V. If it reads some higher voltage than 0V but drops down to 0V if you wait, that is ok. If you read a DC voltage, replace the caps in series with the volume control in the preamp section and the input section of the power amp.

Hi Dr*Audio

Thanks for the great tips. I have recently acquired a Sansui 350 receiver and despite its awful looks inside, now works well except for one vexing problem.

I first list the work done during the past two weeks and then I'll get to the point of the problem.

Repairs: Cleaned the massively dirty and dusty casework, cleaned the dial inside and out, replaced foam strips around the dial as the originals turned to dust, replaced snipped off power cord, cleaned all rca jacks and speaker terminals, replaced all illumination bulbs and cleaned their sockets - (all were blown when I acquired the receiver), repaired broken tuner flywheel, vacuuumed out massive amounts of dust everywhere inside, replaced all fuses with correct value items, cleaned the volume potentiometer with both contact cleaner and silicone free WD-40 type lubricant. Also cleaned all other controls and switches using contact cleaner and WD 40 silicone free. Vacuumed and used compressed air to remove all excess cleaning and lubricating chemicals.

When all of the above was done, I connected the equipment for a duration of 8 hours to our 220V 50Hz mains through a 100W lightbulb and fitted loading resistors at the speaker terminals prior to doing this.

As yet, I have not touched the tuning capacitor other than vacuuming it and using compressed air.

Now the problem: Everything now works correctly, tuning is fine and there are no crackling during function changing except for an intermittent soft crackling sound at low volume at about 1 or 2 minute intervals. At mid and higher listening levels, the crackling or rustling sound through the speakers go away completely.

Last night, I also tried the phono function and this function produces the same symptom - intermittent soft crackling at low volume.

Do you think there could still be residue muck inside the volume pot? On powering down, I usually also turn the volume down to zero. As the equipment powers down and I turn the volume to zero, I can also hear a slight crackle through the speakers.

What do you think could be the problem? - Intermittent soft crackling at low volume?

The pics show the equipment prior to cleaning and all is sparkling clean now except for the spotty chassis.

Thank you for your time.

tripod

 

[redcoates7]

The amount of good advice on this site never ceases to amaze me. Just cleaned up my KT-815 that was starting to make that whooomp-whooomp noise between stations while tuning...just a little Deoxit carefully applied to the brass rod connecting the "gangs" and I'm back in business...clean and quiet!

 

[harpsm]

I wish I'd seen this thread before I started cleaning a newly acquired 70s-vintage Sony 6036a receiver. As a noob to receiver refurbing and having read countless AK posts about how deoxit is the miracle cure for audio connectors and cures halitosis to boot, I sprayed Deoxit D5 into the tuning fins. Now I have to set the FM dial to 93.0 to hear station 88.5 (though my signal strength is still pretty good). I did the "cleaning" about a month ago, and if anything the alignment is only getting worse.

My question is what is the best way to get rid of the D5 residue? Will a non-residue cleaner (e.g., CRC) actually get rid of it? Will mere application and compressed-air drying be enough, or will some scrubbing/wiping be required? Would 90+% isopropyl alcohol work as well?

 

[larryderouin]

CRC QD Electronics Cleaner STRAIGHT UP will clean off the D-5. No compressed air necessary. SPRAY, wait 5 minutes or so and Play. Tilt the receiver so the tuner can is on the down side for runoff. AND SPRAY OUTSIDE. In the sun is preferred for drying time.


ALCOHOL is just as bad an idea as the D-5. It's a good general purpose cleaner but it leaves a residual component.

Larry

 

[dr*audio]

ALCOHOL is just as bad an idea as the D-5. It's a good general purpose cleaner but it leaves a residual component.

Larry

Only if you don't use 99% Isopropyl alcohol or Methanol. If you buy the industrial stuff, it has no residue. There can be residue from whatever you are removing if it isn't all cleaned off the first time.

 

[harpsm]

Success! Well, mostly. I followed Larry's advice and sprayed the tuning fins liberally with CRC QD to remove the Deoxit residue. After it dried, my tuner is now out of line by 1.5 MHz instead of 5.5. I sprayed a second time, but with no additional improvement. I rarely change stations, so I can live with this. Thanks, Larry.