sci.electronics.repair@googlegroups.com

Google Groups

oldschool@tubes.com: Mar 09 08:30PM -0600 There are some sellers on ebay who are selling assorted resistors in quantity. Some of them claim these assortments contain 0 ohm resistors.... WTF. Wouldn't that be a piece of wire?   What would be the point of that?   How would you even color code it?

mike <ham789@netzero.net>: Mar 09 06:41PM -0800 > resistors.... WTF. Wouldn't that be a piece of wire?   > What would be the point of that?   > How would you even color code it?   used as jumpers when you don't have enough pcb layers.

oldschool@tubes.com: Mar 09 07:08PM -0600 What is the correct name for the old style test lead plugs that used to be used on older inexpensive VOMs? They were NOT banana plugs. They were thinner. Same size as the test probes, but much shorter.   I need to get a few of these for some older test gear, but I am not sure what to search for....   Thanks

John Robertson <spam@flippers.com>: Mar 09 05:36PM -0800 > I need to get a few of these for some older test gear, but I am not sure > what to search for....   > Thanks   I always called those "Pin Plugs".   http://www.ebay.com/itm/56-2100-New-3-Ft-Test-Leads-Safety-Test-Probes-to-Right-Angle-Pin-Tip-Plug-/400546944888   I searched for "pin plug test lead -banana"   John :-#)#   -- (Please post followups or tech inquiries to the USENET newsgroup) John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9 (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, Video Games) www.flippers.com "Old pinballers never die, they just flip out."

oldschool@tubes.com: Mar 09 08:25PM -0600 On Thu, 9 Mar 2017 17:36:25 -0800, John Robertson <spam@flippers.com> wrote:     >http://www.ebay.com/itm/56-2100-New-3-Ft-Test-Leads-Safety-Test-Probes-to-Right-Angle-Pin-Tip-Plug-/400546944888   >I searched for "pin plug test lead -banana"   >John :-#)#   Thats what I called them too, but I did not think that was the "official" name.   Thanks

oldschool@tubes.com: Mar 09 07:01PM -0600 What type of capacitor would be the best match to replace the old paper/wax caps in old tube gear?   I am not referring to the electrolytics, those I know need to be electrolytic caps. I am referring to the inter stage caps, such as .01 .05 .1, .005 and so on.....   The object is to replace all the caps in an old tube radio, or any other tube stuff.   Yes, I know this topic was sort of discussed a few weeks ago, and I recall hearing that any of them would work, but that does not really answer this question. Sure, they may all work, but what type would be the closest match to the original paper/wax types?   From what I know, those caps were made from paper and a metal foil rolled up and coated with wax. So, what is the nearest similar type?   From that last discussion, I know I left that thread sort of puzzled because all caps seem tp contain "poly" (which means plastic). I am thinking that what seems to be the closest would be whatever plastic replaces the paper, and a foil. From what I understand, some caps do not have a foil, but rather some sort of metallic material that is coated or sprayed on. Those are probably not what I would want to use, because they are not similar to the originals.   I am fully aware that the voltage MUST be the same or higher and the uf must be close, such as .047 to replace .05. Also for tube circuits, axial leads are preferred.   Then too, looking on ebay and other sources, I see a lot of very expensive caps which are intended for high end audio amps. For my needs, I will not pay $29.99 for one cap, and yes I have seen them cost that much.   I am seeing some no-name cheap China caps selling for as little as 20 cents each. While I like to save money, I'd really rather spend $1 each for something like the Orange Drops, which have been around a long time and seem to be good quality, despite the fact they dont come in axial form. But they generally can fit into most places.   I will only be replacing those paper/wax caps and the electrolytics. I wont touch any mica or silver mica types, unless they appear to be bad (I will probably test them though).   One that I do recall, are the so called Mylar, which I think were the first ones that were made to replace the old paper caps. I guess they now changed that name to something "poly" also.....   What would you recommend or use? Web url's appreciated for lower cost AMERICAN made caps.   One last thing, I found some cap assortments on ebay. 150 or 200 caps of assorted values, labeled as NOS (New old stock), but they are NOT the paper/wax kind. Since I have no spare caps, and just want an assortment on hand, I was thinking about buying one of those. I would NOT buy NOS electrolytics, but for the interstage types, I might consider this, just so I have an assortment of caps on hand..

Trevor Wilson <trevor@SPAMBLOCKrageaudio.com.au>: Mar 10 12:01PM +1100 > on hand, I was thinking about buying one of those. I would NOT buy NOS > electrolytics, but for the interstage types, I might consider this, just > so I have an assortment of caps on hand..   **Just use a decent quality Mylar, polycarb or polyprop cap. If you try to source PIO (Paper In Oil) types, then you'll need the national debt of a small South American nation to pay for one. AND you'll gain nothing. Just a plain ole plastic cap. It'll work and keep working and there will be zero impact on sound quality.   -- Trevor Wilson www.rageaudio.com.au

"tom" <tmiller11147@verizon.net>: Mar 09 09:13PM -0500 <oldschool@tubes.com> wrote in message news:43t3cc9j919psgj3l1jiqerqdcvdd7jo84@4ax.com...   > One that I do recall, are the so called Mylar, which I think were the > first ones that were made to replace the old paper caps. I guess they > now changed that name to something "poly" also.....   Mylar is DuPont's brand name for a stretched PET plastic. P is for poly :)

Foxs Mercantile <jdangus@att.net>: Mar 09 08:17PM -0600 > What type of capacitor would be the best match to replace > the old paper/wax caps in old tube gear?   Were you NOT paying attention previously when we ALL told you to use the yellow plastic caps? 630 volt.   <http://www.tuberadios.com/capacitors/>   Or are you just being stubborn?   Paper dielectric capacitors are crap. They ALL need to be replaced. Trying to "just replace the bad ones" is a fool's errand. They're all bad or will fail after they're "back in service" again.   I have a Collins R-390A receiver on the bench. It's full of paper capacitors. The IF module alone had 18 of them. They have all been replaced. "But it's Collins" and "Those were mil-spec" and and and every other excuse for not changing them. Changing them made a profound difference in how well the radio works.   These parts are bad. Anyone that tells you otherwise is either lying to you or is delusional.     -- Jeff-1.0 wa6fwi http://www.foxsmercantile.com

captainvideo462009@gmail.com: Mar 09 09:40AM -0800 I had this unit in my basement for I don't remember how many years. An old guy gave it to me. He said that it worked and he thought that I could use it. So did I. I think that was about 20 years ago. I always thought that "some day" I might get the 8 track tapes out of the attic and actually listen to them. But realistically, I never will.   So a customer came by recently who wants to buy it. I'm fixing it up for him but he really would like an owners manual. I think this thing came over on the Santa Maria, so I know that it's a long shot, but does anyone have an owners manual or perhaps have a source for one? .   This guy also wants to buy my Benjamin Miracord turn table that I haven't used in years as well. Don't want to let this guy get away. Happy days. No eggs for dinner this week...Thanks for any help. Lenny.

ohger1s@gmail.com: Mar 09 01:41PM -0800 On Thursday, March 9, 2017 at 12:40:37 PM UTC-5, captainvi...@gmail.com wrote: I think this thing came over on the Santa Maria, so I know that it's a long shot, but does anyone have an owners manual or perhaps have a source for one? .   Couldn't have been the Santa Maria. The Santa Maria carried the pizza oven and whores.   There are three of them on Ebay right now. You can try contacting the sellers and ask them if they have a copy they can scan so you know whether it's something you'd like to bid on.

bruce2bowser@gmail.com: Mar 09 11:27AM -0800 > Do not use a long extension wire for the USB.   It shouldn't matter anymore should it? What if the USB extension is over 100'? Do you need extra resistance for the USB load side pins?

"Benderthe.evilrobot" <Benderthe.evilrobot@virginmedia.com>: Mar 09 09:00PM "Johann Klammer" <klammerj@NOSPAM.a1.net> wrote in message news:o9rr11$1t5m$1@gioia.aioe.org... > or sync, so the stuff got actually written out?   > They had an issue once when the files got damaged when you just unplugged > the stick.   Only need one more for a hat-trick..................................................

Jeff Liebermann <jeffl@cruzio.com>: Mar 09 09:37AM -0800 >I have found a part that >fails about 90% of the time on these old devices. They are these old >slide switches (shown above).   See the 4 little tabs holding the switch together? Bend them straight and the slide switch will come apart. Be sure to catch the contacts, springs, and balls before they disappear into the carpet. Clean out all the gunk and goo that accumulates in such switches. If the contacts are pitted or damaged, get a new switch. Reassemble.   However, there's some debate as to how to lube these switches and with what manner of lube. I used to use contact cleaner (mostly solvents and some residual oil) but found that the slide switches didn't last more than a year or two before they again needed "cleaning". So, I switched to using grease, which was probably the original lube. I should use dielectric grease, but found that almost anything will work.   >work at all. (I am awaiting a can of Deoxit from an online order, since >I can not buy it locally). I have my doubts that even this stuff will >fix these switches.   What you might find when you disassemble the switches is a tar like goo covering the contacts. This is a mixture of the original lube, dust, dirt, filth, corrosion, and possibly the remains of the last attack by contact cleaner. The worst I've seen is drywall dust. The switch contacts ride on top of the tar and don't make a connection. There are also contacts that have holes blown into them by arcing or moving the switch with current going through the switch. I would not expect that on a substitution box.   Incidentally, I have fair collection of RF attenuator boxes that use slide switches. something like this: <https://wb6amt.com/96db-attenuator-kit/> The switches need to be very clean for the device to perform properly. The difficult part is determining which switch is failing because all the switches are in series. I will confess to using contact cleaner on these because taking disassembling the switches is rather difficult.   >Do they make more reliable replacements for this type of switch that >will fit the same holes? Heck, even in the 70's when they were only a >few years old, these switches were troublesome.   Sure. Reputable manufactory, correct contact material, and some kind of seal will help. Start here: <http://www.ckswitches.com/product-selection/slide/>   >I never understood the reason for gold plated speaker terminals, but >these switches should be gold plated, or something done to them, since >they were always faulty.   Gold plating should be used for dry loads (i.e. no DC component). If you want DC, use silver. For and RF attenuator or a capacitor substitution box, I would use gold. For a resistor or inductor box, silver. <http://www.digikey.com/Site/Global/Layouts/DownloadPdf.ashx?pdfUrl=A80C3BB324E14E7E80F19776A15429E4> There are also gold and silver alloys to improve things: <http://www.contactechnologies.com/Contact-Technologies-Materials.htm>     -- Jeff Liebermann jeffl@cruzio.com 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558

Boris Mohar <borism_void_@sympatico.ca>: Mar 09 12:47PM -0500 >Regarding this kind of switch:   >http://www.parts-express.com/data/default/images/catalog/240/060-908_HR_0.jpg   http://www.ckswitches.com/product-selection/slide/     Regards,   Boris Mohar   Got Knock? - see: Viatrack Printed Circuit Designs (among other things) http://www.viatrack.ca   void _-void-_ in the obvious place     --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus

Jon Elson <jmelson@wustl.edu>: Mar 09 01:52PM -0600 > While there is truth to this in some cases, I have found a part that > fails about 90% of the time on these old devices. They are these old > slide switches Oh, yes! Those old stamped metal slide switches with the phenolic wafer with the contacts in it were quite awful, and had a short life before they started getting flaky contacts. It might be partly the open nature of the switch, lets lots of air get to the contacts. I just repaced some pretty decent PCB mounted push-push switches that were a definite cut above the cheap ones, but still had a sliding contact spring. But, air and maybe loss of lube had caused the contacts to deteriorate. Exercising the switches just made them worse. This was on 36-year old scientific equipment.   Jon

"pfjw@aol.com" <pfjw@aol.com>: Mar 09 12:24PM -0800 A lot of this has to do with location and storage. I have a lot of Dynaco audio stuff - and David Hafler was notorious for using low-bid/surplus/salvage and "seconds" stuff - that are generally pretty much fine as they have never seen damp, a garage, or unconditioned space in their 38 - 57 year histories. I have a number of vintage radios (TransOceanics) that are up to 30 years older that are also pretty good - as Zenith went at least one step up in initial quality. These switches get flushed before first use in any case.   But rotary and pot switches are a different story. Those I have had to learn to restore and/or rebuild. A PITA, but there are usually only a few bits inside to go bad.   As to caps - unless they are potted or PIO caps, I do not even bother - they get replaced out-of-hand. It is not a matter of "if" but "when".   Enjoy!   Peter Wieck Melrose Park, PA

"pfjw@aol.com" <pfjw@aol.com>: Mar 09 12:28PM -0800 And:   There are kits out there for restorers:   http://www.wisconsinpartsdatabase.com/WISCONSIN/Machine-Parts/Replace/New/Qty-rs-radiospares-maka-switch-rotary-wafer-switch-kits.pl     Peter Wieck Melrose Park, PA

David Lesher <wb8foz@panix.com>: Mar 09 05:36PM Hey Jeff:   I thought of you while on the Wet Coast last month.   I was in Sandy Eggo, where it was 51F and dreary, while warm and sunny on the East Coast.   Then I was tipped to <http://www.sccroadclosure.org/> -- at the time I saw almost every road I knew of listed, save Freedom Blvd, and Fern Flat - but that's private.   I also saw a picture of a <http://testsanat.com/fr/wp-content/uploads/2016/02/6-testsanat.jpg> on a far steeper slope, maybe along 9.   I skipped your area & flew to SEATAC via Sacramento; there was miles of flooded farmland visible.   But the worst indignity was 27 Feb: I left the [MUST SEE] Museum of Flight, and realized I could not see the bus stop midst the snow... and I-5 was closed both ways from a propane tanker sidewise...   I got back to BWI; and it was 80 on Wed.   {not to beat up on Jeff; I like visiting Santa Cruz/Aptos/etc. But..}         -- A host is a host from coast to coast.................wb8foz@nrk.com & no one will talk to a host that's close.......................... Unless the host (that isn't close).........................pob 1433 is busy, hung or dead....................................20915-1433

Savageduck <savageduck1@{REMOVESPAM}me.com>: Mar 09 09:53AM -0800 > Hey Jeff:   Hello Nymshifter.   Now go away.     -- Regards,   Savageduck

nospam <nospam@nospam.invalid>: Mar 09 12:56PM -0500 In article <2017030909531459037-savageduck1@REMOVESPAMmecom>,   > > Hey Jeff:   > Hello Nymshifter.   > Now go away.   false hit.

John Robertson <spam@flippers.com>: Mar 09 10:19AM -0800 On 2017/02/12 10:32 AM, nospam wrote: >> http://i.cubeupload.com/HPg6Xo.jpg   > i doubt he was attempting to cross it. more likely he was not paying > any attention and only realized it when it was too late.   Or the road just collapsed out from under him. It was a landslide, and if it was raining hard (or night) he (or she) may have had no warning at all.   John

"pfjw@aol.com" <pfjw@aol.com>: Mar 09 09:26AM -0800 http://www.bergquistcompany.com/   I have been using as a matter of preference materials from Bergquist for roughly 40 years, albeit in small quantities. Typical output-per-device is at/around 30+ watts. None have failed over dozens of amps at 4 - 20 pads each. Some caveats:   a) There are a LOT of counterfeits out there. Make sure what you use is from a reliable source. b) DO NOT reuse such pads. They will last 40+ years if left alone. But if re-used, they could have micro-tears or punctures from the removal and re-tightening. c) DO NOT use them if the heat-sink or substrate is not smooth and flat.They are not grease that can be used in excess to fill such gaps. d) DO NOT use them with grease/heat-sink compound or any similar material. They can be incompatible.   They are pretty simple, pretty basic, inexpensive items with a single significant virtue - they are not sloppy. So, compound on leads that interferes with soldering becomes a thing of the past (although that is easily controlled with care at application). And there is no measuring issue.   I have also used these:   http://www.talonix.com/shop/item.aspx?itemid=3639 - only because they were OEM. They can be reused. Expensive. For a number of years, AR used them on their US-origin amps and receivers.   With all that in mind, I keep a small stash of Bergquist materials, mica & compound materials and some mica sheeting (also cheap and easy to find at a Jewelry Findings, stove or lamp supply) for unusual situations and/or applications. Such as adjustable mica caps on vintage radios. NOTE: Mica does not like to be drilled - better to punch it. And to make a small diameter mica punch, get a piece of brass tubing with the correct ID, and file it sharp. Punch onto something fairly hard but with some give - I have a piece of maple flooring that I use. You will get perhaps 4 holes and need to resharpen, but you will not flake the mica as you would with a drill. Very sharp tin-snips or professional fabric shears do a nice job of cutting the stuff.   Horses for Courses.   Peter Wieck Melrose Park, PA

MJC <gravity@mjcoon.plus.com>: Mar 09 05:07PM In article <MPG.332b394e49149ff198988d@news.east.earthlink.net>, rmowery28146@earthlink.net says... stuff and the MFD was for the larger capacitors.   > I am not old enough to remember when most all capacitors were called > condensers all the time. For me most electronics was capacitors and the > condensers were used across the points of gas engines.   I learnt about condensers. I expect those motor engineers had only just stopped calling them Leyden Jars! ;-)   Mike.

burfordTjustice <burfordTjustice@tues.uk>: Mar 09 11:52AM -0500 On Thu, 09 Mar 2017 16:45:25 -0000   > it's the postal company's fault, but you still claim from the seller, > and the seller from the postal company.   Wrong again.

You received this digest because you're subscribed to updates for this group. You can change your settings on the group membership page. To unsubscribe from this group and stop receiving emails from it send an email to sci.electronics.repair+unsubscribe@googlegroups.com.