bandswitch cleaning

[K9DXL]

I have an SX101 Mk III and an HQ129X that will be going on the bench for small things eventually.  Thinking it would be a good time to clean/lube their band switches.  Some online posters say de-oxit is the way to go, but at least one I've seen says never use de-oxit emphatically.  Interested in the group's experience in this area.

[nq5t]

I have an SX101 Mk III and an HQ129X that will be going on the bench for small things eventually.  Thinking it would be a good time to clean/lube their band switches.  Some online posters say de-oxit is the way to go, but at least one I've seen says never use de-oxit emphatically.  Interested in the group's experience in this area.

Deoxit is the a good thing.  Clean the CONTACTS.  Don't soak the fiber switch sections with spray trying not to miss anything.

I'm trying to figure out why someone would tell you not to use it .. ?? (scratching head)

[KB2WIG]

"  I'm trying to figure out why someone would tell you not to use it .. ?? "

Worried about "Spray and pray"?

klc

[nq5t]

I guess it would be interesting to know what the "don't use it" comment recommended instead -- the knock-off RS used to sell call Deoxid, WD-40 (good for the shop, but something that has no place on a bandswitch contact) ... ?

[KG4DAG]

I like the Caig "Fader Lube", it's not quite as aggressive as DeOxit and is magical in pots.

[KM1H]

DeOxit is often called DeWrex-It when used incorrectly.

Never use a spray on any switch when RF and voltage is involved, even SS levels. Contrary to denials it can develop a conductive path on ceramic as well as destroy phenolic which is highly hygroscopic.

Ive come to terms with its use over the years and use it very sparingly.

For a rotary switch use the D-100L bottle and use a plastic toothpick, awl, etc to place the smallest drop possible on the switch ROTOR surfaces and paying attention to the rotor wear patterns from the fixed contacts. Also realize many switches have 2-3 seperate sections per side and the other side may have a completely different pattern.

I start with a quick blast of very fast evaporating disc brake cleaner to remove pollutants that DeOxit doesnt work on. Not for use on plastic without testing.

After the switch is dry apply the drops and rotate the switch several times to break thru the corrosion. Wash with the brake cleaner and test the radio. Redo as needed and I suggest one wafer at a time.

I also like to use Tarn-X and a cotton swab on rotors to remove the silver sulfate layer when possible so it doesnt start forming and growing over the contact path as fast. Remove residue with the same brake cleaner

Carl

[W1RKW]

had a rotary switch that had about 200V on it. After hitting it with Deoxit and applying power it arced and sparked. Burned the wafer.  It's a must to clean off any Deoxit residue from places it should not be..

[KK4YY]

I got too aggressive with the DeOxit on the bandswitch of a low-end Halli GC rcvr a few years back and got the fiber wafer wet. Perhaps if had waited for it to dry it wouldn't have started arcing. But I didn't wait. The arcing was somewhere under all those components where I couldn't even see and the brave dare not tread. I used a small transformer to buck the line voltage down and it stopped arcing and the radio worked ok on the lower voltage. Good enough 'eh? But when the Summer arrived and the humidity picked up the arcing returned. I figure it grew a carbon path on or in the fiber material that varies with humidity.

So I now I have either a FB Winter time receiver or a poor mans' relative humidity gauge. I haven't decided which. The thought of what it will take to repair it now has earned the job a pretty low position on my To-do list. Overall, I wish I had the old scratchy bandswitch back.

-Don

[w3jn]

Deoxit it great IF you use it very sparingly, and then only on the contact portion of the wafer.

I wet a qtip with deoxit and wipe it on the metal contact, then rotate it through a few times.  Never had an issue.  Carl's idea of using a toothpickm or an awl to deposit a little drop is good as well.

It's *always* a bad idea to spray things down with wild abandon.  The stuff will soak a coil form and change the Q of the coil, it can get into trimmer caps and wreck their Q, and as mentioned can form an arc path.

[W9HW]

Use Deoxit sprayed on Q-tip here also and never had a problem.
You can also get a bit of scrubbing action with Q-tip for more
aggressive cleaning. Recommend shop Q-tips that are more sturdy
with the plastic stem for shop use to support greater lateral pressure
in tight areas if needed.

Dave

[WA2OLZ]

Not too long ago I totally destroyed a Kenwood T-599A transmitter by liberally spraying DeOxit on every switch, pot, tuning cap, etc. I could find.

After doing so I THEN read the inputs telling me to use it sparingly and judiciously. Probably great stuff when used appropriately, but not the way I did it.

[wa3dsp]

Deoxit is great stuff and I have never had any problems with it. As long as you follow instructions it should be fine. Never use it on live circuits and wait for it to dissipate before applying power.

For everyone that claims bad results there are probably thousands who swear by it. Thats why reading reviews is not always helpful. People complain when they have failures even if it is their fault but they seldom comment about the successes.

While the flammable component of Deoxit dissipates almost immediately there is also now a non-flammable version of Deoxit D5. Even so I still wouldn't spray a live circuit.

[Jim, W5JO]

If you need or want something that will not ruin your switches but will clean and lubricate then try Stabilent 22.  It is available on Amazon and does the same as Deoxit it just won't cause the arcing and swelling of the wafers.  You purchase it in concentrate and mix with denatured alcohol.

[KM1H]

Ive also used Q-tips however it takes a lot of expensive bug juice to wet them plus most of the old junk I get into is too tight and I leave cotton fur behind. What a PITA it is to remove

Deoxit is great stuff and I have never had any problems with it. As long as you follow instructions it should be fine.

The above really says as little as you claim about others. Unless it has recently changed there are no mentions of its suitability in vacuum tube circuits nor any spec on how long it takes to completely dry. The residue that remains a week or more is unacceptable to me and is just asking for trouble.

Also realize that the 5% solution is mostly carrier while the D-100L is 100% and a tiny bit goes a long way.

There are more than enough DeWrex-It horror stories across multiple forums to get the point across to anybody bothering to search and those with long term credible experience are in agreement about the dangers.

It is a lot like those who leave paper caps in a radio claiming it works just fine and only fools destroy the originality. Awhile down the road they are begging for transformers and/or never heard from again. I guess the crow didnt taste good

My own horror story was many moons ago when I sprayed my HRO-500 bandswitch with the 5% stuff but not a lot.... I thought. The wafers were very thin shiny phenolic which likely helped save them compared to older, thicker and more porous ones. It took a month of every other day hitting with brake cleaner before the synthesizer alignment/locks were stable. While this is a SS radio anyone who has looked at the waveforms and how little a change causes a problem can understand. I was having thoughts/nightmares of buying a rusted parts hulk and replacing the switch....a nightmare even worse than a SX-42/62

Carl

[W0BTU]

In my short experience with it (a couple of years), DeoxIT is great stuff. It's the closest thing to magic I've ever seen.  

I followed up the cleaning with D-5L with a tiny amount of DeoxIT S-Shield, applied to rotary contacts with a toothpick.

I've only ever used DeoxIT D5-L, but it is absolutely, positively, the best cleaner for silver-plated rotary switches that I have ever used. By a long shot. I wish I'd have discovered this stuff years ago. There's nothing like it for removing the black junk from the silver (whatever it was) that makes silver contacts intermittent or not work at all. Even worked wonders on the rotary inductor in the pi-net output of my legal-limit amplifier.

The bottle of D5 I bought from Caig Laboratories has a long, thin metal applicator tube that lets you put a tiny amount right where you want it.

The only complaint I have with Caig is that they have so many choices, and don't sufficiently explain what each product on their web site does.

[Opcom]

I used to be too cheap to buy things like de-oxid. Not anymore, after the first time I used it.

[W0BTU]

I used to be too cheap to buy things like de-oxid. Not anymore, after the first time I used it.

Well said! I'm kind of cheap myself.  

The two little bottles -- one bottle of DeoxIT D5-L with applicator, and the other of DeoxIT S-Shield (like a clear oil that eventually dries) with brush in cap-- almost fit in the palm of one hand, but cost almost $50 including shipping. But that was money very well spent indeed. It was worth every penny.

[KM1H]

It would be interesting to note what the ravers actually used it on and where...

I DO find the D5 very useful on vintage automotive and lawn tractor connectors which is where it gets the most use. In tube gear it is usually the last resort as with the water damaged HQ-180 I recently finished for a customer.

I find Caigs marketing a lot like MFJ, sell everything even if its the same thing with a different label.

I love their pricing structure: the D5 5% needle dispenser states .04 ml/drop while the D5 100% has a .02ml/drop opening. Guess which one is the better $$ value; 1250 drops at $29.95 or 625 drops at $24.95. Being a frugal Yankee it is a given which one I bought

[W1RKW]

Agree, DeOxIt is good stuff. Just can't go nuts with it and leave residue.  Otherwise, just dunk the rig in water and turn it on.