Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => AmpTools/Tech Tips => Topic started by: LooseChange on October 26, 2009, 07:32:39 am
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I have been using the Radio Shack jumper leads (Alligator clips on each end) for years. I have also been repairing them for years and the clips weaken up causing bad tests.
Is there a source for a better lead?
Thanks!
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I guess everybody uses the Radio Shack brand?
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I bought a couple packages of about 20 from digi-key. The only reason I am reluctant to recommend them is that I have only had them for a couple of years, and I have not put them under super heavy use. Sorry cant find the product number. The are 12" leads in a pack of 6 or 10. Minature and multi-colored.
caveat emptor.
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I looked up some Pomona jumpers rated for 1,000 volts:
http://www.pomonaelectronics.com/pdf/d6576_101.pdf
Newark Electronics has them,but they cost $9.18 each - yikes! Pomona does make top-notch stuff though.
The other Pomona "patch cords" were only rated for 70 volts. Probably not a big deal in most of our applications, but I never really thought about the voltage rating for a jumper. I've just made my own out of shielded alligator clips and transformer wire clippings.
Don't know if that helps any.
Chip
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I got my last set at Frys. Not much better quality than Rat Shack. Mouser has em: 10 for 4 bones.
http://www.mouser.com/ProductDetail/Silvertronic/501789/?qs=sGAEpiMZZMubtgSkrSNnXI6wTYXL5lgqLK1X2h7i52k%3d
or 10 for 12
http://www.mouser.com/ProductDetail/Kobiconn/13AC010/?qs=sGAEpiMZZMubtgSkrSNnXGghzAVuHwT0UufMQEgw3IE%3d
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I've been using the small, cheap RS jumpers for about 30 years. I also have some heavier duty homebrew cables made using H S Smith gator clips and boots and good quality rubber test lead wire. I use the cheap ones more often than I use the good ones.
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I've got some Rat Shack ones tucked away somewhere.
But what defines good in this situation?
Alligator jaws that hold? Check.
Wire that conducts? Check.
Insulation? Check.
Looks like Rat Shack is good enough to get the job done.
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I must be an animal or I use them way too much.
Alligator jaws that hold? Check.... Not all the time. The springs loosen up.
Wire that conducts? Check.... Yes, but the connections at the clips break.
Insulation? Check.... Check.
I guess for the price I could just chuck them and get another set. :undecided:
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LooseChange, I got these at the local auto parts store. They work great, and I think they'll hold up for ya.
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Wire that conducts? Check.... Yes, but the connections at the clips break.
For connections that will move alot I always try to use wires from SJO extension cords and I try to make mechanical / crimp connections.
most hook up wire is not designed to be flexed very often and will have a tendency to break, especially near a connection. using solder seems to exaserbate the situation.
I really like those hook type clips, the ones that operate lke a syringe and then I use 18ga wire from computer PS cords.
those hooks always seen to grab, even tiny wires. I've had aligators actually miss wires between the teeth, or when the insulation was thick I've managed to straddle the insulation and it never closed on bare wire.
what seems to work best for me is to have a small box of different connectors, alligators,hooks, banana etc with wires I've saved from cords and old probes or what ever looks like would work for jumpers ( soft insulation and lots of fine wires)
On the subject of small boxes for storing things..
tha post office has those flat rate shipping boxes,
I pick up 4 or 5 when I can. I like the smals and mediums best. They are very sturdy, white so you can lable them easily, they stack very nicely so you can store a pretty high density of junque in a small area and best of all they are free.
{-- quote tags fixed --PRR}
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I guess for the price I could just chuck them and get another set.
I was thinking the same thing... :smiley:
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LooseChange, I got these at the local auto parts store. They work great, and I think they'll hold up for ya.
That's the ticket!
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> I got these at the local auto parts store. They work great, and I think they'll hold up for ya.
No. The $4.99 jumper cables, like the $4.99/10 clip-leads, fail where the wire connects to the clip. They are hasty-crimped by low-paid workers and bosses who don't give a hoot as long as they meet quota.
I can't count the number of times I have got bad readings due to bad clip-leads. They gotta be 99.9% reliable or they will lead you astray someday.
Solder the joint. On the miniclips, bite the jaws on a pencil so you can work the jacket off the clip. Try just soldering, but often it is best to bust the wire, peel, strip, and tin-up both wire and clip, then make a good joint. If you get the cheap RS clips, best to get some decent wire as stingray says. On the car-jumpers, you will need a 250W iron (an iron, not a Weller Gun) or work gently with a propane torch. Then crimp the insulation tabs to hold the insulation (you can see these car-jumpers neglected to do this).
While you have those jumper-cables apart for fixing, slip some garden-hose over the handles. Spark-welding a clip between your positive terminal and your fender makes a cold bad day worse.
The hook clips are from another decade. Good ones work good, bad ones are worse even than cheap gator clips. Don't be shy about modding for greater reliability.
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Sounds like i could DIY my own. Anybody got a schematic?
(http://www.butterylicious.com/smilies/classic/runaway.gif)
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Might not be real good, but at the price, they're cheap! Especialy being that the US$ is stronger than the Aussie $. If you need to jump high voltage, use heaps of them 'cos you get 20 leads! :wink:
http://cgi.ebay.com.au/20-Double-Ended-Multi-Colour-Alligator-Clip-Test-Leads_W0QQitemZ350270179243QQcmdZViewItemQQptZAU_B_I_Electrical_Test_Equipment?hash=item518dbac7ab
Kosta
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Check out the clip leads Ted Weber sells on his web site.
He has them in two different sizes and five colors.