Home Grown Test Leads - Page 1
Forum section: electronics / projects

author: berk98
author_rank: Newbie
timestamp: March 17, 2013, 08:36:12 am
content: I've seen very few serious posts on decent test leads here, so here are my home made ones. I thought these were no better than anyone elses, but I've gotten several compliments about these. Any feedback/recommendations are appreciated. All images link to huge versions.The connectors at the right are BFA ones.A while back I bought several long lengths of Monster XP cable from a yard sale. Although they oozed audiophoolery (they have a patent # printed right on the dang cable), I bought them because they came out to about US$0.20/ft which wasn't bad. I also had some gold-plated banana plugs and cheap alligator clips. Before I knew it, I had a handful of test cables.Comparison with my every day Pomona cables. The shadows really show the difference between thicknessesThe Monster speaker cable actually ended up working better than I expected. It doesn't kink, its fairly resistant to my soldering iron, and it looks like it is litz wire which would be excellent for high-frequency AC. Not to mention they feel nice to use. The biggest advantage is being able to make them exactly as long as I need them. The heat shrink tubing also makes for some excellent strain relief.I wish alligator clips soldered as beautifully as he thin stranded wires did.Overall, I would still prefer my Pomona cables. Their minigrabbers and piggyback banana connectors are excellent. I use these cables whenever I can because I trust the thick cables and gold-plated connectors more than anything else I have, but I wind up reverting to others frequently.Whats a product review without some action shots?Bonus: banana plugs fit into many screw-type capacitors!Short cables are amazingly handyAnyone else keep their work bench otherwise clean?The banana plug in all of its pixel-y glory!If you really wanted to make your own, you could pick up some of the same Nakamichi banana connectors I used for just under US$1/ea for a dozen, or about US$4/cable. The Monster XP cable can be had for just under US$1/ft. Alternatively, use some thick stranded cable. Thinner stuff will work with these Nakamichi banana plugs but it seems like if you're cable is smaller than 16AWG, you'll need to double it up for the set screws to reach. The BFA plugs work great in every jack I've tried except the split jacks in my Agilent U1272A handheld meter. I haven't actually tested the contact resistance of them compared to traditional banana plugs, but I can't imagine they are too much better.What do you all think? Should I come up with more cables to share? Should I surrender to the Pomona gods and stick to their products? Should I do a teardown of that Racal-Dana 5003 meter?

author: penfold
author_rank: Frequent Contributor
timestamp: March 17, 2013, 09:21:01 am
content: Best use of audiofool cable I've yet seen!I wouldn't hold out too much hope for the litz wire, but regardless, they're a nice test lead, wouldn't be offended if they turned up on my bench

author: komet
author_rank: Unknown
timestamp: March 17, 2013, 10:11:39 am
content: Apparently those Nakamichi banana plugs have nothing to do with Nakamichi the tape deck manufacturer but are just generic connectors. They might still be decent plugs but if you use them for hi-fi, your soundstage will suffer, definition in the treble range will become grey, a saxophone solo will appear in the middle of Tristan & Isolde, etc.

author: nctnico
author_rank: Super Contributor
timestamp: March 17, 2013, 11:06:53 am
content: I have Hirschmann readily made cables like these (with silicone insulation):http://uk.farnell.com/hirschmann-test-measurement/mln100-1-red/test-lead-red-4mm-1m/dp/523744Don't look too much at the price. I buy them for half that amount from Distrelec which is about the same price if you buy cable and plugs.

author: M. András
author_rank: Super Contributor
timestamp: March 17, 2013, 11:08:44 am
content: just a quick suggestion put some black and red heatshrink over those banana plugs those arent insulated from the conductor i bet on that

author: M. András
author_rank: Super Contributor
timestamp: March 17, 2013, 11:10:42 am
content: Quote from: nctnico on March 17, 2013, 11:06:53 amagreed on this, i dont know what kind of wire they use in their leads but its more flexible and thicker then the fluke test leads, if anyone know the source of those i would gladly buy a whole reel from the most used colors

author: David_AVD
author_rank: Super Contributor
timestamp: March 17, 2013, 11:48:50 am
content: +1 about adding insulation around those banana plugs. That's just an accident waiting to happen.

author: saturation
author_rank: Super Contributor
timestamp: March 17, 2013, 01:55:08 pm
content: Very handsome cables. They should work for their intended task.IMHO, an ideal cable should be:SafeLosslessNoiselessErgonomicLow costIn that order. Real cables have specific limits and you obtain them to work within the limits of your task.If these cables are made for crude DC work such as everyday power cables or patch cables, safe, lossless [ e.g. IR drop on them] and ergonomic would be more important than being noiseless. Cheap would be good since everyday use tends to get them injured or damaged. Unprotected banana or alligators clips are not regulation connectors today.But if they were for metrology grade use, such as I see an MV106 in the photo, you'd want to be able to resolve to 1uV or better as the MV106 is capable off. If one were to custom make those cables, I'd love to get the 100nV resolution out of the MV106.The source of noise is materials and construction of the cable as well as the connectors, and it tends to make it costly on its own so look or ergonomics are distant consideration. Its less often used, so cheap isn't as big an issue. I find using short coax a good overall low voltage DC cable down to 100nV [ see attachment], but to make it shorter than 1m, which is the run of the mill construction, and connectors of good quality [ Amphenol or equivalent] versus namless China variant, you'd have to experiment with manufacturers and truly make your own.http://na.tm.agilent.com/pna/connectorcare/Connector_Grades.htm