Hi NareshBrd,
Well, this is a very small control. Small dimensions. The fewer holes we go poking into it, the less chance of damage. Let's not tempt fate. The OP is also not accustomed to doing this.
I've never drilled more than one hole and never had to. Now about cleaners ... they all destroy the factory lubricants and you need them. The resulting damage takes years to show up as wear, so while you may think you did a great job, tell me in a decade. You absolutely do not want to introduce anything, no oils - nothing. You want to clear the oxides without damaging other surfaces. The bushing for the shaft will be vulnerable here and that is what you need to protect. Therefore use only as much as needed to get the job done, no more.
Controls are designed to clean through use. If you don't use a control the oxides build up. So occasional use is your best defence against a noisy control.
Well, this is a very small control. Small dimensions. The fewer holes we go poking into it, the less chance of damage. Let's not tempt fate. The OP is also not accustomed to doing this.
I've never drilled more than one hole and never had to. Now about cleaners ... they all destroy the factory lubricants and you need them. The resulting damage takes years to show up as wear, so while you may think you did a great job, tell me in a decade. You absolutely do not want to introduce anything, no oils - nothing. You want to clear the oxides without damaging other surfaces. The bushing for the shaft will be vulnerable here and that is what you need to protect. Therefore use only as much as needed to get the job done, no more.
Controls are designed to clean through use. If you don't use a control the oxides build up. So occasional use is your best defence against a noisy control.
This is a random image of a pin vise, a watch maker's tool.
I use this for fine holes, very handy, and easy to control.
I have ruined two pots by using an electric drill in a place where there was no room, and the drill went through the wall very quickly, could not react.
This takes a couple of minutes more, but works.
For PCBs, I use 0.8 mm drill bits, the through hole wires are 0.6 mm.
1/16" is 1.59 mm, close enough to 1.6 mm.
As for oils, a close look at the MSDS of De-Oxit and WD40 shows both are about 75% hydro treated naptha, aka transformer oil, well regarded for high dielectric strength.
The suggestion to use a syringe was because the needle would go through a fine hole, and the alcohol would clean off the gunk, which was based on my experience here in dusty conditions.
May not be right advice for somebody in cooler climes.
You are right, the minimum amount of chemicals should be used, particularly on old equipment, the plastics would have aged already, may not be at full strength any more.
I am Naresh, in Baroda (Vadodara), Gujarat State, India. Last name must be in profile.
Basically mineral based lube oils are made by adding additive packages to a refinery product type called Lube Oil Base Stock, which is available in different viscosity, which are standardized by the API and the SAE, the ASTM is also involved.
You then blend different additive packages to get engine oil, transmission fluid, gear oil, front fork oil, textile spindle oil, hydraulic oil, and so on.
Similar process for grease.
The cleaner chosen here must be a no residue type, without additives that make it adhere to the job, it must drain away.
I think 0.1 ml or so, injected with the syringe at 2 ml (rest is air), will be enough.
The air will give the effect of a spray, so the entire volume inside the pot will get a small coat.
I bow to your practical experience of many decades, and your experience as factory service agent for Carver, among others.
You are much more qualified in this than me.
I am sorry if I have caused any offense.
Hi NareshBrd,
No offense taken at all. No worries.
My background includes test and measurement equipment. Requirements are exact and tight, but audio has the exact same principles. However, there isn't a culture of "doing it right" in audio and other fields. We should.
You do not want any oils or anything in a control or switch. There is dielectric grease, but that is applied manually and not "squirted" in. So, when the control is manufactured. This may be counter-intuitive, but look at it from another viewpoint. Most of these additives oxidize over time. They also attract pollutants, dust - you name it. So think long term. Will an oxide layer reform if the part isn't used? Yup, it sure will, but you can just clean it again.
The fact that I did Carver warranty has little to do with anything. More, the service people that mentored me, the one man that I had to prove I was worth training, reading data sheets with an open mind and all the on-the-job training. Then experience to show where I was wrong or right. Doing Revox warranty, and Marantz taught me most about mechanics and cleaners. Servicing stuff butchered by others clearly shows what does not work well! lol!
-Chris
No offense taken at all. No worries.
My background includes test and measurement equipment. Requirements are exact and tight, but audio has the exact same principles. However, there isn't a culture of "doing it right" in audio and other fields. We should.
You do not want any oils or anything in a control or switch. There is dielectric grease, but that is applied manually and not "squirted" in. So, when the control is manufactured. This may be counter-intuitive, but look at it from another viewpoint. Most of these additives oxidize over time. They also attract pollutants, dust - you name it. So think long term. Will an oxide layer reform if the part isn't used? Yup, it sure will, but you can just clean it again.
The fact that I did Carver warranty has little to do with anything. More, the service people that mentored me, the one man that I had to prove I was worth training, reading data sheets with an open mind and all the on-the-job training. Then experience to show where I was wrong or right. Doing Revox warranty, and Marantz taught me most about mechanics and cleaners. Servicing stuff butchered by others clearly shows what does not work well! lol!
-Chris
Carver, Revox and Marantz had complex circuits compared to the utterly reliable Japanese units.
The fact that you serviced them routinely itself makes you better than most.
So, I agree with your assessment, use as little as possible...
The fact that you serviced them routinely itself makes you better than most.
So, I agree with your assessment, use as little as possible...
You've never seen a Yamaha where they decided to get creative, or some excellent (but complicated) Sansui units. Then of course there are horribly complicated and nonsensical Japanese tuner alignments, Kenwood being notorious for this. By comparison, Revox had a lot of alignment, but it was straight forward, made sense and you ended up with a world beating tuner in performance. I use a B261 for that reason.
Onkyo, Yamaha, Denon, Sony Trinitron...the trouble prone Japanese sets.
In comparison to sales numbers, the overall excellent quality of the Japanese saw far less units for service, percentage wise.
On Sony Trinitron, we routinely put 15 A transistors in place of the standard 4 A units in the SMPS. One spike (very common here at that time), and the TV was wrecked. Had to rebuild the SMPS, and weird issues if not done properly.
Even non Toshiba transistors caused issues.
One Welsh (UK) built Sony TV was giving a repairman a hard time, horizontal rolling, he had spent three days, and I just mentioned casually I had seen a service bulletin from Sony, two tantalum caps in the power supply were from a defective lot, and that was the cause.
He was not very convinced, at his wits' end, he changed them, and voila!
After that he gave me respect, small jobs were at mates' rates...but that told me Sony had some peculiar designs.
In comparison to sales numbers, the overall excellent quality of the Japanese saw far less units for service, percentage wise.
On Sony Trinitron, we routinely put 15 A transistors in place of the standard 4 A units in the SMPS. One spike (very common here at that time), and the TV was wrecked. Had to rebuild the SMPS, and weird issues if not done properly.
Even non Toshiba transistors caused issues.
One Welsh (UK) built Sony TV was giving a repairman a hard time, horizontal rolling, he had spent three days, and I just mentioned casually I had seen a service bulletin from Sony, two tantalum caps in the power supply were from a defective lot, and that was the cause.
He was not very convinced, at his wits' end, he changed them, and voila!
After that he gave me respect, small jobs were at mates' rates...but that told me Sony had some peculiar designs.
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Ahhh, TVs are audio are two completely different things. Example, Panasonic makes great TVs, horrible audio. Sony is similar.
I never did service TV sets. Terrible business. I had to working for others, but once I got out on my own I avoided them, and that worked very well for me. Completely different mindset as well.
I never did service TV sets. Terrible business. I had to working for others, but once I got out on my own I avoided them, and that worked very well for me. Completely different mindset as well.
STK 403-90 in Sony sets was run at +/- 45 V, Pioneer ran them at +/- 40 V, max spec was +/- 50, so while the Sony gave more power, it was nearer the safe limit, would have failed faster.
But it was fun to observe the regular improvement, the early 70s chrome went to dull black in just a decade, and performance was much improved.
As for Panasonic, @wiseoldtech said they stopped selling TV in 2011.
Maybe they sell in other countries.
How was their Technics audio brand?
But it was fun to observe the regular improvement, the early 70s chrome went to dull black in just a decade, and performance was much improved.
As for Panasonic, @wiseoldtech said they stopped selling TV in 2011.
Maybe they sell in other countries.
How was their Technics audio brand?
Technics sound quality is terrible, always was. Same as Pioneer. Build quality for Technics is better than Pioneer. Probably equal now for many years. Junk.
I deal more in the higher end product in audio. I would refuse to do Sony, Pioneer and like stuff under warranty. Denon was actually better than most. STK based amplifiers never did perform well either.
Anyway, we are way off topic now. Let's see what akacree comes back with.
I deal more in the higher end product in audio. I would refuse to do Sony, Pioneer and like stuff under warranty. Denon was actually better than most. STK based amplifiers never did perform well either.
Anyway, we are way off topic now. Let's see what akacree comes back with.
@NareshBrd Although you may not have the experience of Anatech on Carver repairs, I appreciate the advice and expertise from you as well. THANK YOU
- I just learned what a pin vise is. It seems appropriate for the job, as I'd be much more likely to protrude beyond what's functionally-necessary otherwise. I'll shop for a decent one and get that ordered.
- I looked up anatomy of a potentiometer & learned what a wiper is. Not sure where the wiper would be on this pot, so it would be a guess to know if I was covering the wiper with the cleaner. Either way, I (think) I get the gist: hold vertically, shaft up, plunging the syringe towards the shaft base should do the trick to cover the wiper(?)
- Do you have any suggestions for a relatively cheap/value cleaner with no residue?
Okay, the shaft goes through the control. Around the shaft is a metal ring - the slip ring, on the same plane as the resistive element. It is connected to the centre terminal. The wiper is a metal ring with fingers connected to the shaft, it contacts the slip ring. The other fingers contact the resistive element that is concentric around the slip ring, spaced further out. Each end is normally connected to the end terminals. Your control is a little different, but the idea is the same.
It's called a "pin chuck" here. Eclipse makes a good one. That's what I use and suggested.
It's not the pot, it is the correction of your problem. This is what a good technician goes through with the simple line "cleaned controls". The pot is cheap if you could get one, but you still have to replace it. So, what is that worth? Don't say "I can buy another one for $$$", because you're getting a used item that needs service. I'll drop a customer if they say that.
It's called a "pin chuck" here. Eclipse makes a good one. That's what I use and suggested.
It's not the pot, it is the correction of your problem. This is what a good technician goes through with the simple line "cleaned controls". The pot is cheap if you could get one, but you still have to replace it. So, what is that worth? Don't say "I can buy another one for $$$", because you're getting a used item that needs service. I'll drop a customer if they say that.
https://en.m.wikipedia.org/wiki/File:Potentiometer_cutaway_drawing.png
That will help you understand.
I think a small dual 47k pot should be available, it is about $2-$3 here in India for Bourns, the local ones start about 20 cents.
There was also Preh in Germany, now Chinese owned.
A search for '6 mm dual pot 47k ' will give many results.
Plan B is to solder a 22k resistor to each end on the PCB, join their other ends, and connect the center joint to the center in the PCB.
Basically, the 47k is from the entire track, and center will be at 23.5k, 22k is the nearest standard value.
So a 22k from each end in series, will give 44k, and the center tap will go to center pin.
You can turn your pot upside down, and fix the knob, for appearance.
I had to do that on a set of computer speakers, weird pot, not available...so I shorted out the volume control with a 1k instead of 10k, to keep it at 90% volume, at full volume it would overload the supply and distort the sound.
Chris, please do not roll your eyes!
Or shudder...this is a terrible hack.
22k + 1.5k = 23.5k, you can do that if you are finicky.
23.5 k* 2 = 47 k
One end - <23.5k>- center point - <23.5k > other end on PCB.
Center point goes where the wiper is connected on PCB.
I think it is clearer now for you to understand.
23.5 k* 2 = 47 k
One end - <23.5k>- center point - <23.5k > other end on PCB.
Center point goes where the wiper is connected on PCB.
I think it is clearer now for you to understand.
Hi NareshBrd,
That control doesn't work like that. Please read back.
If you can get it quiet in the centre position, install it so you can have the knob in place.
That control doesn't work like that. Please read back.
If you can get it quiet in the centre position, install it so you can have the knob in place.
Thanks for the heads up...
OP, drill in the corner, front or back, away from pins, that is the safest, away from the tracks.
Front and back will allow you to flush if you want to.
OP, drill in the corner, front or back, away from pins, that is the safest, away from the tracks.
Front and back will allow you to flush if you want to.
I think the small gap between the front threaded cast part and the blue plastic may allow the introduction of maintenance fluid with a syringe.
It is tiny, and the corners seem to have rivets or screws as fasteners, so making a hole in the corners will be difficult.
It is tiny, and the corners seem to have rivets or screws as fasteners, so making a hole in the corners will be difficult.
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