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Author Topic: OLD rig deadly PCB capacitors-Hallicrafters etc..  (Read 1065 times)
ZS5WC
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« on: September 05, 2004, 05:15:17 PM »

Which old rigs used the very toxic PCB caps?-
Should I worry about my Hallicrafters S40b and SR150 or
Collins KWM-2a and 75a4.?
How about my TR7 supplies-or MLA2500?.
If some of them do contain the bad caps-where do I get replacement items.
Any info will be appreciated!.
Best Regards,
William
ZS5WC-73!
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KA5N
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« Reply #1 on: September 05, 2004, 05:49:31 PM »

Capacitors with PCB's are usually oil-filled types made before 1979.  Most capacitors in ham gear are mica, ceramic, beeswax, paper, dry electrolyic and won't have PCB's.  Do a Google search on PCB in capacitors and you get lots of information.  Usually the problem was with LARGE capacitors or transformers with lots of cooling oil.  Even then the problem was with those leaking oil.  As far as your post about the odor, I suggest you narrow down the thing that is stinking and check it out.
Allen
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AC5E
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« Reply #2 on: September 05, 2004, 06:38:07 PM »

William, while there just might be some component with a very small amount of PCB's in old gear, it won't hurt a thing unless it is leaking. And even then it won't hurt you unless you swallow it or leave it on your skin for a long time. So the risks aren't worth worrying about.

As far as repair parts are concerned, the most common items will be "paper" capacitors and electrolytic caps. Resistors are less likely to fail completely but more likely to shift beyond tolerance.

Most of the older gear used Allen Bradley/Ohmite resistors and it's hard to find components that "look original." Generally, I replace defective resistors with same resistance same wattage units, and if appreciable current flows in them I usually go up one size on dissapation. That is, I replace an original 1K 1/2 W unit with a 1K 1 W unit.

Modern replacemnt capacitors will work fine as long as you have the same or greater voltage rating and the same capacity in microfarads or micromicro, er, picofarads.

Filter and bypass electrolytics can be a size or two larger - a 40 mfd at 450 V will work just fine for a 10, 20, or 30 mfd at 450 V or less. Even used caps can work well, as long as the capacity is within the usual -50% +200 % tolerance that was common in older production caps. Just note that if you take a 450 V rated cap that's had 25 V across it for some time it's best to increase the voltage slowly so the cap can "reform."

Modern replacement capacitors also work fine as replacements for "Paper" caps, the largish tubular jobbies from .001 to .5 mfd, 200 to 600 WV ranges. I like Sprague's Orange Drops, but others have different tastes. Some go so far as to remove the guts from an original "Black Beauty" or "Red Devil" and put a replacement cap inside the shell. Everyone to their own taste, of course, but that seems a lot of work no one will ever appreciate.

Most power and audio transformers are available as either good used or NOS originals - and the NOS seem made of solid gold these days.

RF and IF transformers are scarce and hard to find. Be careful working around them because an open coil can turn a fine radio into an attractive paperweight.

Hope that gives you some ideas and 73

Pete Allen  AC5E
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WIRELESS
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« Reply #3 on: September 05, 2004, 08:05:00 PM »

I find it odd that so many people are concerned with PCB's (and should be) when there are many other nasty chemicals and materials also in electronic stuff that few seem to be concerned with.  One substance that is in alot of solid state stuff is BeO (berillium oxide).  This stuff is in just about every high power diode, transistor and some IC's.  BeO is deadly if inhaled, comes in contact with anything that goes in your mouth, or just contact with the skin.

Some of those cleaners hams use that they buy have some hydrocarbons that are also deadly. Do you put your hands on anything that goes in your mouth while soldering?  If so you are eating lead.

It pays to read labels.  I quit using alot of items after reading the warning labels.
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K0RFD
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« Reply #4 on: September 05, 2004, 09:34:09 PM »

One way to prolong your life is to be afraid of so many things you give up Ham radio.

It may not actually make you live longer, but without the enjoyment of Ham radio, it will certainly seem that way.

Besides, one of my greatest criticisms of living longer is that they tack the extra years on the WRONG side of your life.  If they could give me my 20s or 30s over again 2X, they might have an audience.  However, the way they currently do it, I could care less.
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AB5ON
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« Reply #5 on: September 05, 2004, 11:18:26 PM »

I may be wrong here.  Sometimes my memory is not too good. (maybe exposure to all those PCBs and RF from my cellphone)

I used to work on equipment that did use PCB filled caps in the power supply filters.  As I remember it we were trained to clean up spills with rubber gloves, but did not have to call out the HazMat team or decontaminate the affected area.  I also recall they had a bigger concern about the PCB's ending up in the landfill and polluting water supplies than they had about having technicians exposed to the chemical.

Anyway, most of us that handled PCB filled caps and pulled cable thru asbestos filled ceilings in rooms with lead based paint are still around to talk about it.

Rick
AB5ON
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N6AJR
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« Reply #6 on: September 05, 2004, 11:58:57 PM »

I don't think new solder has any lead in it any more
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KC8VWM
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« Reply #7 on: September 06, 2004, 02:41:36 AM »

PCB's are overrated. Are you gonna drink the stuff?

Equally toxic is the tar that is distilled to make plastic components for your radio microphone and dials. Known to case cancer in the state of California!

 
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W8JI
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« Reply #8 on: September 06, 2004, 07:43:04 AM »

What a bunch of paranoia all these warnings have produced!! I can't recall ANY commonly produced rigs that contained anything with PCBs.

PCB's were popular in the 60's and earlier, and only then in very large capacitors and oil-cooled HV transformers. Virtually ALL components used in commercial amateur gear were pcb free, and youwill never fond it in small rigs like Valiants, Collins S lines, Rangers, Globe Scouts, Swans, Hallicrafters, and so on!

It isn't even that dangerous if you have components that contain PCB's. The danger is in handling direct exposure to skin over long periods of time, or ingesting it in small quantities for many years. The same is true of all the other things like lead or light petro chemicals, or smoking. It all take LONG periods of time or massive quantities for shorter periods.

Even the berlyium thing is WAY overblown. Most berylium is found in harmless alloys. Even if the alloy is ground into small chips, the berylium remains bonded or suspended and isn't toxic. It's a good idea to NOT grind up transistors and snort them, or put ground transistors in your vaporizer, but all this paranoia probably causes more health problems than the actual compounds everyone worries about do.

73 Tom
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N8FVJ
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« Reply #9 on: September 06, 2004, 10:04:46 AM »

I'll take a chance on that 75A-4 if the price is right.
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ZS5WC
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« Reply #10 on: September 06, 2004, 04:01:12 PM »

Thanks guys for all your input!.

I suppose I was getting hyped about nothing-after all , I hear some fellas used to use transformer oil-(containing PCB) for suntan lotion!.
Also,we used to work with an industrial cleaner-Bichlorotrifluoroethane-(I think that is almost correct..), that also was highly toxic-(we did not know it at the time)-and some days we were basically swimming in the stuff-(the same stuff that would clean old radio chassis very nicely..)
--AND I have not snorted ground up transistors yet-wonder if letting the smoke out would have the same effect..

Thanks for putting my mind to rest-I enjoy old rigs, and also love to restore them to good working condition-I just wondered if I should be taking special precautions.
Thanks for the info regarding parts-sure will come in handy.
The lead free solder-well I think it is another hooh-hah about nothing-instead of dumping electronics into landfill sites they could dispose of the pCB's containing lead some other safe way-chemically perhaps.

P.S. the 75a-4 is not for sale-......

Best Regards,
William
ZS5WC
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WA2JJH
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« Reply #11 on: September 07, 2004, 10:40:11 AM »

THE only piece of ham gear that could be a PCB hazzard are a small number of old oil cooled dummy loads.

  Heathkit was first with the cantenna dummy load. You could fill it with harmless mineral oil or toxic PCB tranformer oil.

  However most hams used mineral oil because you can buy it at any drug store.
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K2WH
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« Reply #12 on: September 07, 2004, 08:42:52 PM »

In the industry and in the eyes of the EPA, mineral oil is no longer a safe item.  Mineral oil must now be disposed of properly with all the regulations that PCB oil is subject to.

I'm and X-GE power system transformer engineer and we had techs and engineers practically bathing in the PCB stuff.  All their kids are normal.  Myself, I could not touch the stuff.  Made me break out in a rash.  Also, someone said something about an odor.  Pure PCB oil has a sickening sweet smell to it.  Mineral oil smells like... OIL.

K2WH
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