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Author Topic: G-K RB400 On w/no sound  (Read 8984 times)

Roly

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Re: G-K RB400 On w/no sound
« Reply #15 on: July 11, 2013, 03:39:06 AM »
Quote from: Kaz Kylheku
The brand name DeOxit is priced like it's some of elixir of immortality made from the extract of the flower of a rare herb that only thrives in one single tiny forest somewhere in Nepal, and blooms only for one week, once every 23 years.

...gathered by comely virgins on the full moon (who make $1000/m speaker cable on their days off).

Thanks for the clue about oleic acid.

Quote from: Enzo
You can pay twice the real price by getting it at Radio Shack.

Also known here as Tandy, "utterly clueless", and several much less flattering names.  Bought out by Dick Smith Electronics, itself having been bought by supermarket chain Woolworths, now the whole lot flogged off "for a bargain price of $20 million" to some investment company Anchorage Capital Partners and about as far removed from its roots as a component supplier as one could get; the whole mess now Zombiefied walking dead.  May they all rot in hell.

Quote from: Enzo
but getting it into the aerosol can is trickier.

Artists have a neat little mouth-powered gizmo called an air brush, and I use drinking straws like a pipette ('course with Vodka you can suck as well as blow, to good effect).

I wouldn't have had (as big) a problem if the radio station had been using DeOxit, or in fact anything that was actually a contact cleaner, but the particular CRC they were wedded to was a moisture dispersant for drying out electrical stuff like tractor wiring and contained a high viscosity oil as well as light fractions.

I had a Paddy Roberts LP one time which advised that "This record should be cleaned with a very dry martini".  MP3's are nearly as much fun.
If you say theory and practice don't agree you haven't applied enough theory.

Kaz Kylheku

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Re: G-K RB400 On w/no sound
« Reply #16 on: July 13, 2013, 01:55:35 AM »
Quote from: Kaz Kylheku
The brand name DeOxit is priced like it's some of elixir of immortality made from the extract of the flower of a rare herb that only thrives in one single tiny forest somewhere in Nepal, and blooms only for one week, once every 23 years.

...gathered by comely virgins on the full moon (who make $1000/m speaker cable on their days off).

Thanks for the clue about oleic acid.

But, wouldn't you know it, oleic acid is also priced wildly, like the milk squeezed from the teats of Buddha.

Some medical grade of it ready for use with bacterial cultures and can set you back a hundred bucks for a measly 25 ml!

Some other grades are more reasonably priced, like 25-30 bucks a liter.

Check the lab chemical suppliers "Sigma-Aldrich" and  "VWR".  I contacted the chemistry department at my old alma mater, UBC, and they tipped me off to these.
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J M Fahey

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Re: G-K RB400 On w/no sound
« Reply #17 on: July 13, 2013, 02:48:32 AM »
FWIW I checked my Industrial supplier price list.

Oleic acid is *cheap: less than U$5 a liter.

Only drawback is he sells it by the 200 liter drum (55 Ga. drum)

But I'll ask at a smaller chemical retailer shop.

Even if he charges U$10 or 15 a liter, it's cheap.

Enzo

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Re: G-K RB400 On w/no sound
« Reply #18 on: July 13, 2013, 03:22:23 PM »
This is all well and good, and that stuff may be the majority ingredient, but it isn't the only ingredient, so this isn;t one of the cases where, "all you have to do..."


Next up, I'm saving animal fat from my cookstove and ash from my fire.  Tomorrow we'll have SOAP!!

J M Fahey

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Re: G-K RB400 On w/no sound
« Reply #19 on: July 14, 2013, 03:51:50 AM »
Agree that it must not be the only ingredient, and even worse, it *must* have some nasty chemical (in very small amounts) which is very important.

FWIW I make soldering flux (mainly to spray my just etched PCBs) out of pine rosin and alcohol or toluene (depending on how fast I want it to evaporate and what buzz I want to get today :(  ) but I know that an ingredient which "accelerates" soldering and lets it attack much dirtier copper is one form of **mercuric chloride** (or bichloride).

Poisonous as H*ll  :loco

No way I'm touching or breathing that .

Ok, Multicore solder already has it ... but I'm not adding any on my own will, so .....

Additives "improve" products but many times they are *very* nasty.

http://www.nlm.nih.gov/medlineplus/ency/article/002474.htm

Kaz Kylheku

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Re: G-K RB400 On w/no sound
« Reply #20 on: August 13, 2013, 10:57:54 PM »
Quote
Do not use lubricant on electrical contacts!
???
Quote
A lubricant is a film of some hydrocarbon, silicone or fluorocarbon.

What do these materials have in common? They don't conduct!!!
That's *exactly* the point, we don't want randomly conducting stuff there.

Quote
When you put a lubricant film between metal contacts, you're creating a capacitor.

If and only if they do not touch each other .... which is not the case.   ::)

Okay, J.M. has set my head straight about this.

After some weeks of experimenting, I'm a convert: lubricant is good, at least in sliding contacts.

Hypothesis: the coating provides an oxygen barrier, inhibiting oxidation, and when you insert the plug into the jack, it wipes off, allowing for the metal surfaces to cut through and make contact.

I have used this product to clean all the jacks and plugs in my rack. Guitar to rack, between the rack units, and power amp to speaker:

http://www.kleenflo.com/en/productpages/4168.htm

I use this light machine oil on bicycle chains and all small lubrication tasks that don't call for something specific.

The audio results are fantastic. Smooth, silky, well-articulated sound. I just did a re-application because I was hearing something "off", some harsh brittleness in the tone. It was instantly gone.  The bass response is excellent, which dispels the hypothesis that the film creates poor contact combined with capacitance that lets through higher frequencies.  Obviously there is good DC contact.

So, to heck with boutique contact cleaner: a $6, half-liter bottle of oil does the job.

This particular stuff is great: according to the MSDS it has hydro-treated as well as napthenic oil, a petroleum solvent to help it penetrate (smells like fuel or naptha), as well as zinc alkyldithiophosphates: anti-wear, anti-corrosion additives.

Someone has studied the latter in connection with electrical connections. I'd love to get my hands on the full text of this paper: http://link.springer.com/article/10.1023%2FA%3A1019175509680 "Electrical contact resistance studies on zinc dithiophosphates".

Now I wouldn't go as far as using oil on non-sliding contacts, because of the lack of a wiping action to cut through the film. Oil inside a relay? Forget it! The best thing for non-sliding contacts is to be oxidation-free, enclosed in an air-tight container that is filled with an inert gas. E.g. magnetic reed switches are that way.
« Last Edit: August 13, 2013, 11:01:07 PM by Kaz Kylheku »
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J M Fahey

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Re: G-K RB400 On w/no sound
« Reply #21 on: August 13, 2013, 11:40:07 PM »
Quote
Hypothesis: the coating provides an oxygen barrier, inhibiting oxidation, and when you insert the plug into the jack, it wipes off, allowing for the metal surfaces to cut through and make contact.
Yes, that's the point.
Besides oxygen, air contains corrosive gases , sulphur dioxide among others (a byproduct of burning fuels) which together with ambient humidity makes sulphuric acid, and other nasty products.
Exposed copper/brass/silver/tin get a thin but murky film which both disturbs plain contact and solderability.

FWIW a few years ago some 7.65mm Argentine Mauser rifles were sold.

Made in Germany in 1895!!!! they had rested unused covered in thick protective grease , wrapped in waxed paper, resting inside mold and moth eaten humid wooden crates.

They were in *PERFECT* condition, like fresh out from the Berlin factory !!!

One of the metallurgical shop maxims: "Grease is the Machine's Friend!!!!"

Roly

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Re: G-K RB400 On w/no sound
« Reply #22 on: August 14, 2013, 12:01:09 PM »
Just a little point that many relay contacts are constructed so that they do wipe, but something to seriously avoid are things that contain silicon compounds as this has immense surface tension and can migrate along metres of cable and form insulating silicon oxides on contacts.

Do you have much of a problem with Mause's over there JM?  We don't have them here.  Mice, Drop Bears, sundry snakes and spiders, but no Mause's thank goodness.  {Don't tell me, let me guess, they sell them alongside the pickled Armadildos, right?}
If you say theory and practice don't agree you haven't applied enough theory.

Kaz Kylheku

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Re: G-K RB400 On w/no sound
« Reply #23 on: August 16, 2013, 09:42:33 AM »
I got some syringes from a drug store and now I'm injecting oil into pots. Very good results.

I measured a slightly lower wiper resistance in one test unit. It went from 1.5 ohms to 1.0.

The one in my guitar is absolutely silent at high gain, and feels almost strangely smooth, like you're turning a hot glass rod stuck into paraffin wax or something.

Little by little I will work my way through all the pots, including the 31 sliders on the graphic.
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J M Fahey

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Re: G-K RB400 On w/no sound
« Reply #24 on: August 16, 2013, 09:10:12 PM »
Just compare the top 4 elegant Argentine Mause(r)s to the chunky rough British Lee Enfield at bottom.

Included just because beauty is always relative to something else  :lmao: