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Re: 91% Isopropyl Rubbing Alcohol to clean potentiometers?
A better cleaner for pots is Caig Faderlube. It has a little lubricant in it and will not attack the resistance strips. Also works on wire wound pots.
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Another place to get dry IPA is at a computer store or department. They usually have 99+% in either bottles or spray cans. IPA absorbs moisture until it becomes 91% which is why its not usually stocked in the dry form. Dry IPA will become 91% if exposed to the air for very long. I think the spray can version probably stays dry for longer than the bottled kind. On 3/5/2019 5:28 PM, Bill Carns wrote:
If you go to a pharmacy and talk with the Pharmacist, they can give you IPA with a higher percent IPA and less water. This is better for pots, but be careful to not saturate. Sometimes you can damage the carbon resistance layer that is laid down for the wiper to run on. I am not sure if that is true for the ones TEK uses. --
Richard Knoppow dickburk@... WB6KBL |
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Re: 91% Isopropyl Rubbing Alcohol to clean potentiometers?
Deoxit D5 or DN5 followed by fader lube is what I do. The D5 gives it a good washout and the fader lube adds some lube hence the lube part of the name.
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On Tue, Mar 5, 2019 at 07:56 PM, Bill Carns wrote:
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Re: CSA803 advice
I am in central Arkansas about 75 miles NNE of Little Rock. Pretty much the middle of nowhere. That's the good part and the bad part.
Color display is a non-issue. I care about the DAQ and repairability. I just received a 100 pS spike generator from Leo Bodnar. it's a modified version of his 40 pS rise time square wave generator. Absolutely awesome! It's very close to a minimum phase Gaussian pulse. I don't know what sampling head he is using on his CSA803 (I've asked), but I suspect that it is not an SD30 or SD32 from the appearance of the trailing edge in the plots that came with the unit. If it's an SD24 or SD26 he's banging up against the BW of the sampling head. This thing is *fast*! I now have both the square wave and the impulse versions. If you are trying to test and calibrate scopes, you need a pair. They are an incredible bargain relative to anything else I know of. In oil industry seismic work, the standard way of testing the AFE and ADC is to input an impulse. Nyquist is typically 250 Hz, so it's very easy to generate a clean impulse. With that recorded on tape before you start acquiring data it's very easy to fix any issues during processing. And spot that it's too broken to use until fixed. Normal processing practice is to zero phase the data which is not physical, but it's a lot easier for the seismic interpreter to pick the time of a symmetric waveform. |
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Re: 91% Isopropyl Rubbing Alcohol to clean potentiometers?
Well, the danger there is if it is dying from deterioration of the element, then that will only make it worse.
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-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of wilson2115@... Sent: Tuesday, March 05, 2019 7:41 PM To: [email protected] Subject: Re: [TekScopes] 91% Isopropyl Rubbing Alcohol to clean potentiometers? Thanks, I will check into that. Ideally, what would be the best solution I should use. Perhaps maybe I could run the pots back and forth about 500 times. |
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Re: 91% Isopropyl Rubbing Alcohol to clean potentiometers?
Chuck Harris
IPA won't help the problem with noisy pots.
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Pots get noisy for several reasons: In the cheaper pots that have deposited carbon elements, the noise is often caused by the wiper grinding its way through the carbon, and leaving holes. These can sometimes be fixed by moving the wiper to touch other parts of the element... but the accuracy of the pot is already compromised. Some cheaper pots have the insides open to the outside, and are dust magnets. A naptha (lighter fluid) wash and lube job will help. In more expensive pots, the noise is caused by the lubricant getting hard, and lifting the wiper off of the resistance element. Again naptha to clean and a pot lube to lubricate. I use DeOxit Fader lube for most pot elements. There is also a DeOxit synthetic grease... one of the PPA's, but I haven't tried it yet. 99% IPA becomes 91% IPA shortly after the bottle is opened. IPA is good for a lot of things, but it is weak at removing old grease and pot lubricant. Use naptha. -Chuck Harris OBTW, 91% IPA is fine for flux removal on PCB's. wilson2115@... wrote: I have some 91% Isopropyl Rubbing Alcohol sitting around and I have a Tek 577 with dirty horizontal and vertical display controls, I have used this to clean residue on circuit boards and grime off surfaces and it works quite well so I was wondering if it could be used to clean the dirty potentiometers on the 577 curve tracer. 91% seems the best the best I can find. I also have a can CRC Lectra Clean. What are your thoughts, recommendations? Thanks |
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Re: 475 on a K212 cart?
Yes, it came with the straps which can be positioned in front, center, or rear slots in the tray. Will have to play around with it a bit, as my scope has a DM44 and accessory pouch on top. I will need to replace the 'retaining bar' to secure the scope feet to ensure it does not slide out. Looks like plain aluminum channel. The K212 manual on TekWiki lists the part as BAR,RETAINING:11.6 L X 1.0 W X 0.375 THK,AL CH,6063¨CT52
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Re: 91% Isopropyl Rubbing Alcohol to clean potentiometers?
Richard Solomon
Just don't cause a spark !!
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73, Dick, W1KSZ On Tue, Mar 5, 2019 at 6:41 PM <wilson2115@...> wrote:
Thanks, I will check into that. Ideally, what would be the best solution I |
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Re: 91% Isopropyl Rubbing Alcohol to clean potentiometers?
Bob Albert
I think isopropyl alcohol is so mild it not only isn't likely to damage anything but also isn't likely to do much good either.? I quit using it long ago due to lack of results.
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In the old days it was carbon tetrachloride.? When that was yanked off the market it was replaced by another chemical whose name eludes me at the moment.? When that was made illegal its replacement was 1,1,1 trichlorethylene that got banned.? That's the best one I ever used and I still have enough of it to do any cleaning jobs. I have used denatured alcohol with varying success.? Acetone is a last resort; it's very powerful.? Brake fluid is potent as well and I wouldn't use it on anything without the utmost care. I see there is something called de-oxit but I am skeptical.? I haven't used it, and it seems overpriced.? (Of course, WD-40 is less than worthless for this or, for that matter, for anything electronic.) The problem with a noisy pot can be due to various causes, dirt being an infrequent one.? I think it's often corrosion/oxidation of the wiper surface, although sometimes it's wear and tear of the carbon element surface (for frequently used controls).? If the pot is used infrequently it's more likely chemical action.? Also corrosion of the interface between the wiper terminal and the wiper. More often than not, simply exercising the pot solves the problem.? Just rotate the knob at least a couple hundred times.? Find the bad spot and put it there, then twist back and forth until your wrist aches.? When you recover, do it again.? I can't tell you how many times this has solved pot noise problems for me.? Perhaps it's a weak spring in the wiper mechanism. Some circuits are poorly designed in that there is unnecesary dc flowing in the element.? A leaky blocking capacitor also can cause dc that creates noise when there is no signal. So the answer, as usual, is that there is no simple answer.? It depends. Bob On Tuesday, March 5, 2019, 5:38:15 PM PST, Richard Solomon <dickw1ksz@...> wrote: I prefer De-Oxit Fader Lube. Works great. 73, Dick, W1KSZ On Tue, Mar 5, 2019 at 6:12 PM <wilson2115@...> wrote:
I have some 91% Isopropyl Rubbing Alcohol sitting around and I have a Tek |
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Re: 91% Isopropyl Rubbing Alcohol to clean potentiometers?
Deoxit is the best product I have found. Use it all the time on old audio
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gear with scratchy pots Don On Tue., Mar. 5, 2019, 8:12 p.m. , <wilson2115@...> wrote:
I have some 91% Isopropyl Rubbing Alcohol sitting around and I have a Tek |
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Re: 91% Isopropyl Rubbing Alcohol to clean potentiometers?
Richard Solomon
I prefer De-Oxit Fader Lube.
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Works great. 73, Dick, W1KSZ On Tue, Mar 5, 2019 at 6:12 PM <wilson2115@...> wrote:
I have some 91% Isopropyl Rubbing Alcohol sitting around and I have a Tek |
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Re: 91% Isopropyl Rubbing Alcohol to clean potentiometers?
If you go to a pharmacy and talk with the Pharmacist, they can give you IPA with a higher percent IPA and less water. This is better for pots, but be careful to not saturate. Sometimes you can damage the carbon resistance layer that is laid down for the wiper to run on. I am not sure if that is true for the ones TEK uses.
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Bill -----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of wilson2115@... Sent: Tuesday, March 05, 2019 7:13 PM To: [email protected] Subject: [TekScopes] 91% Isopropyl Rubbing Alcohol to clean potentiometers? I have some 91% Isopropyl Rubbing Alcohol sitting around and I have a Tek 577 with dirty horizontal and vertical display controls, I have used this to clean residue on circuit boards and grime off surfaces and it works quite well so I was wondering if it could be used to clean the dirty potentiometers on the 577 curve tracer. 91% seems the best the best I can find. I also have a can CRC Lectra Clean. What are your thoughts, recommendations? Thanks |
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91% Isopropyl Rubbing Alcohol to clean potentiometers?
I have some 91% Isopropyl Rubbing Alcohol sitting around and I have a Tek 577 with dirty horizontal and vertical display controls, I have used this to clean residue on circuit boards and grime off surfaces and it works quite well so I was wondering if it could be used to clean the dirty potentiometers on the 577 curve tracer. 91% seems the best the best I can find. I also have a can CRC Lectra Clean. What are your thoughts, recommendations? Thanks
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Re: CSA803 advice
You should get at least one SD24 as it has the TDR function. Also, there are some (two) battery backed ram chips that should be replaced. The ones used have the battery in an adapter socket that the CMOS 8mb rams plug into. Sometimes you can score a good deal when the seller does not know why the self test are failing.
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The triggering is not straightforward like on a normal analog scope. I think the C version has a color display. Where on the planet are you? Shipping one of these could be costly. Regards, Tom WA3PZI On 3/5/2019 7:26 PM, Reginald Beardsley via Groups.Io wrote:
I'm considering buying one, but did not find a lot of information on the Tek wiki about the differences between the A and C models. I assume there was a B, but information is sketchy. |
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CSA803 advice
I'm considering buying one, but did not find a lot of information on the Tek wiki about the differences between the A and C models. I assume there was a B, but information is sketchy.
I'm considering a pair of heads SD24 or SD26 and SD30 or SD32 Advice? Things to watch out for? I assume they are somewhat fragile given the BW. If anyone has one to sell please contact me off list. Thanks, Reg |
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Re: 475 with no Display and no HV
Hi Jim,
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The Museum of Radio and Technology is located in Huntington, WV about 15 minutes away from the Ohio, Kentucky boarder. We get visitors from all over the country and the world, for that matter but many folks that live in state don¡¯t know that we exist. If you are a Amateur Radio operator and have never been to Hamvention you could tie a trip to both places together. Many do. Ripley The words are mine but this iPad does what it will with them. On Mar 5, 2019, at 2:55 PM, Jim Olson <v_12eng@...> wrote: |
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Re: still trying to track down 2216 manuals
Q service has a 2212 service manual on CD on ebay for 14.99 they are saying it has the large pages also, so I'm guessing that means the schematics included?
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On March 5, 2019 at 10:42 AM "Colin Herbert via Groups.Io" <colingherbert@... mailto:colingherbert@... > wrote: |
Jared Cabot
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