HP 6236B Triple Output Power Supply (w/ talk about GPD-3303S) - Page 1
Forum section: electronics / testgear

author: JenniferG
author_rank: Frequent Contributor
timestamp: February 25, 2017, 06:19:51 am
content: While I was on the forums all day here reading and posting messages, this poor lil' guy was chilly outside on the front porch! Just opened up the box just now. Wow it's really good condition. Turned it on, the needle popped up to 20V, adjusted the voltage down and the needle went down. The orange power light came on to the right of the power switch. Well that's about all I've done with it.Scored it for $45 plus $15 shipping from ebay -- a University that was selling it. I feel like I got a bargainWill be great for building & testing op-amps, sound modules etc. It was recommended to me by a friendly Muffwiggler DIY guy who uses it.Two channels / bipolar 0-20V, with current limiter set to 500ma internally. And another channel of 0-6V if I recall at 2a.I might be able to mod it, adding a dial to the front, allowing me to limit the current to a range of smaller values vs. a fixed 500ma. But perhaps not necessary. I'm not really sure as I'm a newb.

author: bitseeker
author_rank: Super Contributor
timestamp: February 25, 2017, 06:51:25 am
content: Yep, that's a good power supply. Although it doesn't have adjustable current limiting, it does have short circuit protection. Plus, it's got a big heatsink, so no noisy fan. It should serve you well.Note that the supply's limits are printed on the front panel beneath the model and name.

author: JenniferG
author_rank: Frequent Contributor
timestamp: February 25, 2017, 06:58:33 am
content: I suppose I should get one of those GPD-3303S Linear DC Power supplies as well. 3 Channels, linear and up to 3A 0-30v.Good for larger stuff. I presume it has great adjustable current limiting as well.To get through ARt of Electronics do I need one of these GPD-3303S or can I get by with the HP 20v 500ma HP I just got?EDIT: Had I known about this Instek GPD-3303S deal I probably would of just bought it instead of this HP. But I guess having two power supplies is good at times for certain things. Been watching some vids on the GPD-3303S and wow it looks pretty darn terrific. I can get one in almost flawless condition for $150 including shipping off ebay. That along with the GDM multimeter for $100.. I'd be pretty set.

author: bitseeker
author_rank: Super Contributor
timestamp: February 25, 2017, 07:32:43 am
content: You should be able to get through AoE with the HP. One of the recommended power supplies is the HP E3630A, which is like your 6236B, but with digital displays instead of analog.If you get one of the GPD-3303S, beware that there are two versions, but with the same model designation. One has all the banana jacks equally spaced and the other doesn't (channel 3 is spaced further from the other two). You don't want the one with the equally-spaced jacks because it has a voltage overshoot problem on Channel 3. There are a couple of threads here about it.Some sellers don't know that there's a difference and have been known to substitute one for the other despite what the listing photos show. So, be sure to ask exactly what the one you're buying looks like. Of course, if it doesn't match the listing photos or description, you can return it under eBay's Buyer Protection policy.

author: JenniferG
author_rank: Frequent Contributor
timestamp: February 25, 2017, 07:45:46 am
content: Quote from: bitseeker on February 25, 2017, 07:32:43 amThank you. Just the info I was looking for with respect to which version of the GPD-3303S I should buy.

author: mtdoc
author_rank: Super Contributor
timestamp: February 25, 2017, 07:49:05 am
content: I have an HP 6236 (among other PSUs). It was one of my first power supplies.I like it a lot. The tracking outputs are nice when you are playing with op-amp circuits. In some ways a lack of current limiting can be good when starting out since a lot of learning takes place when the magic smoke escapes...You definitely scored well with that price and are well on your way to TEA membership.Quote from: JenniferG on February 25, 2017, 06:58:33 amAh em... Yes - two, three, ten, twenty.... some of us feel you can never have too many-- Speaking of which I just bought a GPD-3303S and need to send it back tomorrow due to the mix up on versions (seller did not send the one in the picture) that bitseeker is refering to.

author: JenniferG
author_rank: Frequent Contributor
timestamp: February 25, 2017, 07:51:59 am
content: So this basically: )

author: bitseeker
author_rank: Super Contributor
timestamp: February 25, 2017, 07:53:48 am
content: Quote from: mtdoc on February 25, 2017, 07:49:05 amYep, even when we do. This ITT liquidation is really hard on my TEA. But I've not succumb, yet.

author: bitseeker
author_rank: Super Contributor
timestamp: February 25, 2017, 07:55:33 am
content: Quote from: JenniferG on February 25, 2017, 07:51:59 amYes!

author: mtdoc
author_rank: Super Contributor
timestamp: February 25, 2017, 07:56:19 am
content: Yep. I bought from a listing with the correct (bottom) picture but was sent one like the top picture.Just to be clear, the overshoot issue is only on the fixed 2.5-3-5 V output on the far right. The 2 main outputs are fine. It's not really that big of a deal (and likely an easy fix) - but still - I purposely ordered one I thought would not have that issue.So, I would recommend messaging any seller you buy from to be sure they know specifically what you want.

author: JenniferG
author_rank: Frequent Contributor
timestamp: February 25, 2017, 07:57:03 am
content: Quote from: bitseeker on February 25, 2017, 07:53:48 amFortunately for me, since I am such an early user, I have excuses since I don't really have any gear :>

author: JenniferG
author_rank: Frequent Contributor
timestamp: February 25, 2017, 09:45:33 am
content: Going through the manual and it wants me to do a "TURN-ON CHECKOUT PROCEDURE".Been going through it. But I skipped the steps where it wants me to short common to +6VDC and common to +20VDC, observing the amp meter. LOL, I am afraid to! Bzzt! Hopefully the current limiting works and I don't get sparks!

author: Berni
author_rank: Super Contributor
timestamp: February 25, 2017, 09:59:40 am
content: Quote from: JenniferG on February 25, 2017, 09:45:33 amWell better that you know the current limiting works rather than having everything blow up when you connect your circuit to it, including your circuit you worked hard on.Besides if the PSU does blow up if you do that then you can go and fix it so it works like it should and you will learn a lot while troubleshooting and repairing it. The old HP gear is easy to fix due to having nice service manuals and it brings a lot of satisfaction when you do manage to get a old quality piece of gear working like new again.By the way don't worry too much about it, even crappy non current limited power supplies tend to survive a short circuit for a second or two since the failures tend to be purely thermal and it takes a while for things to heat up. So if current limiting doesn't work it should just output way too much current rather than suddenly blow up with sparks and smoke.

author: JenniferG
author_rank: Frequent Contributor
timestamp: February 25, 2017, 06:20:09 pm
content: Thanks. I did the the current limiting tests and the ammeter showed the correct current values, according to the instruction manual.Someone on muffwiggler just shared this mod he did to his 6236B -- smd led lights above the meters. I so want to do this! I was thinking about lighting up the meter last night, even before I saw this photo. Makes it so much easier to read!

author: bitseeker
author_rank: Super Contributor
timestamp: February 25, 2017, 06:44:58 pm
content: That meter lighting mod looks good. I've been considering doing that to some of my supplies, but with amber LEDs to give a warm glow like the power indicator. Of course, it depends if the needle color blends in too well.

author: rstofer
author_rank: Super Contributor
timestamp: February 25, 2017, 07:47:26 pm
content: Quote from: JenniferG on February 25, 2017, 07:57:03 amHang around here for another week and you'll need a bigger house!That power supply should work fine. In the "Learning..." book, they talk about the Global Specialties PB-503 prototype board and it has a triple output supply like yours but nowhere near as complete. Like it doesn't have meters...http://www.globalspecialties.com/electronics-trainers/analog-a-digital-circuit-design-trainers/item/97-pb-503.htmlThat should give you a benchmark on the equipment required. Nothing special...You could put some inline fuseholders in your power supply leads and get some very low current fuses. OTOH, there is nothing quite like the smell of magic smoke.

author: Berni
author_rank: Super Contributor
timestamp: February 25, 2017, 08:08:07 pm
content: Quote from: JenniferG on February 25, 2017, 06:20:09 pmNice to hear.That mod does look nice but i would rather use very warm white color LEDs to make it look like its lit by incandescent bulbs as some of these meters used to be. Extra points if you add a soft start circuit to make them slowly fade on.

author: bitseeker
author_rank: Super Contributor
timestamp: February 25, 2017, 11:24:41 pm
content: Quote from: Berni on February 25, 2017, 08:08:07 pmFade on. Nice touch! And dim slightly when the current gets too high?

author: JenniferG
author_rank: Frequent Contributor
timestamp: February 25, 2017, 11:46:58 pm
content: I like the idea of the incandescent look; I'd definitely want that! All my Philips LED bulbs here have a nice warm color temperature.Maybe not as bright either.. He put a row of SMD above. Maybe it needs half the amount.Looking that photo above and mine, I see that my power lamp doesn't have it's little dome ><

author: Cerebus
author_rank: Super Contributor
timestamp: February 26, 2017, 03:01:16 am
content: I have an HP 6236B in my collection, it's become the everyday PSU because it hasn't got fans - ah, peace and quiet. It's also notable for how electrically quiet it is too. The specs for noise and ripple on any output are 0.35mV rms, 1.5mV peak-to-peak 20 Hz to 20 MHz - confirmed as still in spec on my 1984 vintage model. You'll struggle to find figures as good as that on many modern PSUs - Keysight's newest analogue PSU models come in at 10mV peak to peak.

author: JenniferG
author_rank: Frequent Contributor
timestamp: February 26, 2017, 06:21:08 am
content: Quote from: Cerebus on February 26, 2017, 03:01:16 amThanks, I'm glad I bought this.

author: K5HJ
author_rank: Regular Contributor
timestamp: February 26, 2017, 07:26:43 am
content: I've had one of these for over 25 years and other than replacing an electrolytic capacitor it just keeps on working.You can short all of the outputs to ground or to each other, walk away and it will not be damaged.These supplies are bullet proof.Randy

author: JenniferG
author_rank: Frequent Contributor
timestamp: February 26, 2017, 07:51:22 am
content: Quote from: K5HJ on February 26, 2017, 07:26:43 amI need to learn how to test an electrolytic cap. [Yeah I know how to discharge it -- I usually test voltage after I think I've discharged it just to make sure it is really discharged. And I never use 2 hands near big caps like that -- don't want current going across my heart.]I've tested one before but only with a capacitance meter checking the uF only. I've learned recently that isn't enough and I need a $100 or so LCR meter.

author: Berni
author_rank: Super Contributor
timestamp: February 26, 2017, 08:35:51 am
content: There are capacitor ESR testers out there for quickly checking if a electrolytic cap is at the end of its life.But you could do it with a oscilloscope too. If you discharge a capacitor in to a low value resistor to create Amps of current flow out of it you can see the ESR in the voltage curve. If the capacitor is good the curve should look close to a textbook capacitor charge/discharge curve. But when there is a lot of ESR on the capacitor the voltage will suddenly jump down with a sharp edge, flowed by that expected smooth discharge curve. That jump is the voltage drop on the capacitors internal resistance caused by the sudden large current. If you measure how big that drop is you can use the value of your discharge resistor and some math to find the internal resistance of the capacitor.

author: SingedFingers
author_rank: Frequent Contributor
timestamp: February 26, 2017, 09:04:43 am
content: Nice supplies those 6236B's. I did AoE 2nd edition with one in about 1996! Literally just bought it's successor yesterday, the E3630A as I regretted selling it years ago. If you want to get through AoE cheaply you can make do with one supply. I did when I did the old 2nd edition anyway. Had an 8xAA battery box and a croc clip lead as a second supply. If not the new HY1803D linear supplies are dirt cheap and aren't terrible.Also skip the PB-503 breadboard. Spend the money on a nice sweeping function generator. HP 3312A is spot on for that course.Incidentally I did the AoE course, then I did an EE degree and the AoE course was far more valuable.Testing electrolytic capacitors... I'd just ignore this. They are almost certainly fine if the supply is operating correctly. Don't diagnose a problem until you have one.Don't worry about current limiting to start with at all. There isn't much risk of anything spectacular happening at the supply's hard limit. You can afford to chuck the odd smoked resistor or transistor. It's different when you're dealing with large assemblies or expensive ICs but then you can get some mileage by putting a 100 ohm resistor in series before power up. If that gets hot, something is amiss.

author: JenniferG
author_rank: Frequent Contributor
timestamp: February 26, 2017, 09:19:14 am
content: Quote from: SingedFingers on February 26, 2017, 09:04:43 amWow thanks for all that useful infoReally cool to have people here willing to give a newb some advice to get me going in the right direction. I am quite excited actually to start going with this. I don't work so I have a lot of time on my hands and this would be as good a way to spend extra time. My goal is to learn enough to where I can design cool and interesting things and make them a reality. Also, want to save a lot of money building my own modular synth instead of the individual expensive modules.Yeah I have no intentions of buying that bread board. I bought a bunch of MB-102's for $2 from china. I love this breadboard spring vise tool that breadboards sit in. I printed it on my 3D printer. It should do the job[Cost me like $1 in plastic to print.. uses rubberbands to the wings are self-adjusting.. they really hold any pcb well!]http://www.thingiverse.com/thing:957376I also mount switches, knobs and what not on little perf board to make them breadboard friendly (a few examples in the above photo I snapped).I'll have to look into that HP sweeping function generator. Is it not something an iPad or PC SOund card could produce? Too low of Freq range? i.e. 20k

author: JenniferG
author_rank: Frequent Contributor
timestamp: February 26, 2017, 09:33:07 am
content: Found one of those HP sweeping function generators for only $120 plus $24 shipping:http://www.ebay.com/itm/HP-AGILENT-3312A-13-MHz-FUNCTION-GENERATOR-/162321403239Missing a knob, allegedly works.

author: SingedFingers
author_rank: Frequent Contributor
timestamp: February 26, 2017, 09:42:54 am
content: Not a bad price. Paid more than that for mine but I'm in the UK and quality gear is far more expensive. The missing knob is actually a button cap to set the cal position for the offset so this is likely fine.Here's what you get for your money:Also it has AM and FM modulation and burst/pulse support which is useful for playing around with filters, PLLs and digital. The thing is a swiss army knife without having to spend on DDS kit.Edit: regarding using a sound card, probably not. For a ton of labs you need a 50 ohm output impedance and a large voltage swing. That generator also hits 13MHz which is far higher than you can get out of a sound card. Sound cards are really useful though for audio and things like THD analysis so don't discard that idea

author: bitseeker
author_rank: Super Contributor
timestamp: February 27, 2017, 12:35:02 am
content: Quote from: JenniferG on February 26, 2017, 07:51:22 amUnless your power supply is misbehaving or showing a lot of noise on its outputs, you don't need to check the caps in it. However, it is good to have an ESR meter for troubleshooting. Bad capacitors are a very frequent cause of power supply problems in all kinds of devices.You don't have to spend a lot of money, though, on a tester since a bad capacitor's ESR will be significantly higher than a good cap's. Grab yourself one of the ATmega-based ESR tester kits (tests more than just capacitors). They run $10-30 depending on the model and whether or not it comes assembled or with a case. Search for the "$20 transistor tester" thread. Plenty to read and the software/hardware is open-source.If you like/prefer analog testers, search for the "5 transistor ESR tester" thread. It's a very simple circuit to build and works with an analog panel meter.

author: K5HJ
author_rank: Regular Contributor
timestamp: February 27, 2017, 04:56:56 pm
content: I had to replace C36 in the reference supply. The symptom was low output voltage due to the reference being too low.This can be verified simply by checking voltages, a capacitor meter is not really necessary. I got by for many years without one.Randy

author: JenniferG
author_rank: Frequent Contributor
timestamp: February 28, 2017, 12:12:34 am
content: Just bought the Instek GPD-3303S as well (the version without overshoot problem). $144 including shipping -- allegedly in great condition.. We'll see! Anyways, I hope this was a smart move / value.

author: JenniferG
author_rank: Frequent Contributor
timestamp: February 28, 2017, 10:31:49 am
content: So I got this new HP power supply as you know:But I have absolutely no leads for it. What would be be the best way to get the power from this supply to an MB-102 breadboard strip? As is, I'd just loosen the the terminal knobs, wrap a piece of 22 awg wire around it and tighten it, then just hook that wire directly into the board. I am assuming there is a better way?Just as Iwasclueless about probes & lead kits with my Fluke 8050A (got that cleared up thankfully), I am clueless about leads for HP power supplies. Do these receive unprotected male banana plugs? Is there a standard connector for most all test power supplies, as there is a standard for most DMM's? Do I want silicone coated leads instead of pvc?What would be the best brand to get? i.e. best value (affordable but good). e.g. I am settling on Probemaster kit for $28 for my DMM. Just need something similar for this test supply and whatever adapters I need to safely get the power to some MB-102s.Thanks

author: SingedFingers
author_rank: Frequent Contributor
timestamp: February 28, 2017, 10:51:40 am
content: Use a breadboard with binding posts attached to it. I use one of these (and a couple of Wisher ones) which have a metal base and binding posts:Then run 4mm <--> 4mm banana leads to it. Connect your instruments to the binding posts OR use minigrabbers to connect them in circuit. Don't try and connect everything up using bits of wire and binding posts. If you move anything it'll rip bits of your circuit out.I'll post a picture later of my set up but I'm about to go on a conference call for 2 hours (fun).

author: Cerebus
author_rank: Super Contributor
timestamp: February 28, 2017, 12:29:35 pm
content: Quote from: SingedFingers on February 28, 2017, 10:51:40 am+1 on all of that.Additionally a couple of tips to go with it.Develop a personal colour code for dealing with multiple supplies and polarities and use it to choose what colour leads to connect your breadboard and PSU. Pick colours that match your breadboard's posts. If the binding posts on your board don't have the right colours or a restricted range of colours, cheap nail varnish is a good medium to use for re-coding them. That way if you physically disconnect your PSU to use for something else, you've a good chance of not mis-connecting it when you reconnect it to the breadboard. Where possible, keep the same physical order on PSU and breadboard binding posts.Some time youaregoing to hook your PSU up the wrong way to your breadboard. Cue !BANG! and release of the magic smoke. A handy trick to minimize the damage you can do is to strap some reverse biased diodes between the binding posts on your breadboard. That way if you get it wrong you'll only apply 0.6V or so 'the wrong way around' to any components on that particular power rail and your PSU will harmlessly go into current limit. Pick big beefy diodes rated to handle the full load of your PSU for at least 60 seconds. A 3A 2W diode is going to be quite sufficient unless you're using a monster PSU. This doesn't protect you from all possible mistakes, but it does catch the commonest ones.Note that if you use that last trick and you do end up mis-connecting your power cords it may take you some time to find the problem because the PSU and diodes will just quietly deal with the problem. However, I'd rather be scratching my head for 10 minutes than picking bits of exploded electrolytic cap out of my grizzled beard or, as happened to me last time I got this wrong, looking at the dead, smoking remains of £7 worth of LM399 voltage reference.

author: SingedFingers
author_rank: Frequent Contributor
timestamp: February 28, 2017, 12:48:49 pm
content: Excellent idea with the diodes. That mistake has as well cost me a few opamps, electrolytic caps and nearly an eye or two in the past

author: JenniferG
author_rank: Frequent Contributor
timestamp: February 28, 2017, 01:55:40 pm
content: Thanks guys. I suppose I should be wearing protective glasses anytime I build a circuit.

author: SingedFingers
author_rank: Frequent Contributor
timestamp: February 28, 2017, 02:06:33 pm
content: I tend to wear them most of the time. Clipping leads is probably more dangerous based on probability.

author: Cerebus
author_rank: Super Contributor
timestamp: February 28, 2017, 04:06:46 pm
content: Can't abide safety glasses if I can avoid them (which is not always).A common trick is to have a sheet of clear acrylic handy, with some stand-offs in the corners or just a couple of bits of 4x1 timber screwed to the edges. Before you first power a breadboarded circuit on you just cover the whole thing with the sheet. It also stops you dropping tools into the middle of a layout, bending pins and sending components flying; which, of course, I havenever*ahem*done.

author: mmagin
author_rank: Frequent Contributor
timestamp: February 28, 2017, 05:08:43 pm
content: With properly-functioning sub-1 amp current limits on low voltage circuits, I've generally not had anything explode when I applied power.The one reason I like having an adjustable current limit (as compared to the 6236B mentioned above) is that I can set it low enough to usually not even damage ICs if I connected things wrong. But most parts are cheap, so it's not a big deal.

author: mtdoc
author_rank: Super Contributor
timestamp: February 28, 2017, 06:59:01 pm
content: Quote from: JenniferG on February 28, 2017, 10:31:49 amI agree with SingedFingers that a breadboard with binding posts is the best way to go. But for those times you aren't using one of those type of breadboards, good banana jack to minigrabber test leads work well. Just use a short length of 22 gauge solid core wire to connect between minigrabber and the breadboard power rails.You can get high quality ones for a good price at Franky's eBay storehere

author: JenniferG
author_rank: Frequent Contributor
timestamp: February 28, 2017, 07:10:04 pm
content: Didn't know you could use the same test leads you'd use on a probe, on a power supply.

author: bitseeker
author_rank: Super Contributor
timestamp: February 28, 2017, 09:52:10 pm
content: As long as they're 4mm banana plugs, they'll work. It's just wire. Just note that some jacks work with shrouded plugs and some don't. Having a couple of leads with retractable shrouds can be handy sometimes because they'll work in either kind of jacks.If you have a university nearby, check Craigslist or similar. Students often sell off their lab kits when they're done with them. They may have banana leads, scope probes, BNC patch cables, passive components, ICs, etc. depending on the class.As for current limiting, one could make a circuit as an add-on to the power supply's output, if needed.

author: SingedFingers
author_rank: Frequent Contributor
timestamp: February 28, 2017, 10:01:23 pm
content: When I did university they supplied all our kit, which we promptly pilfered

author: BU508A
author_rank: Super Contributor
timestamp: February 28, 2017, 10:15:17 pm
content: Quote from: JenniferG on February 28, 2017, 07:10:04 pmPerhaps this is a stupid question, but do you have a solder station?With this and some nice tools you can assemble some cables for your needs.And sooner or later you need one anyway.Examples for imho good soldering stations:http://www.ebay.com/itm/JBC-HD-2B-Power-Lotstation-mit-Lotspitze-470-014-/222417228778(soldering tip C470-014 recommended in your case, probably the C470-013 for finer soldering works)http://www.ebay.com/itm/Hakko-FX951-66-FX-951-Digital-Soldering-Station-FH200-01-Variety-Tip-Bundle-/161807824599http://www.ebay.com/itm/Weller-WESD51-Digital-Soldering-Station-with-Chisel-Tip-Bundle-Tip-Cleaner-/171943304353(the soldering tips aren't the smallest but one can find them quite easily on ebay)

author: JenniferG
author_rank: Frequent Contributor
timestamp: February 28, 2017, 11:10:15 pm
content: Yes I have a cheap Velleman soldering station with a simple pot. Right now I'm working on getting a proper one with temperature control In the sub $100 range -- analog not digital.

author: JXL
author_rank: Regular Contributor
timestamp: March 01, 2017, 01:13:29 am
content: Quote from: Cerebus on February 28, 2017, 12:29:35 pm+1 on the binding posts/banana jacks. You can't have too many of them. I use heatshrink tubing to color-code my cables and the jacks on the breadboard & power supplies.

author: Cubdriver
author_rank: Unknown
timestamp: March 01, 2017, 06:16:57 am
content: Nice score on that HP supply.For interconnects, I like the stacking banana cables from Pomona Electronics. This Digi Key link should get you to a page showing them:http://www.digikey.com/products/en/test-and-measurement/test-leads-banana-meter-interface/627?k=Pomona&k=&pkeyword=Pomona&pv970=63&pv970=60&pv970=56&FV=fff40023%2Cfff80405%2Cffe00273%2C2dc0eae%2C33c0223%2Cb5800c7%2Cb5c00c7%2Ce0c000e&mnonly=0&newproducts=0&ColumnSort=0&page=1&quantity=0&ptm=0&fid=0&pageSize=25They're not cheap, but are well made and will last. Buy once, cry once.-Pat

author: JenniferG
author_rank: Frequent Contributor
timestamp: March 01, 2017, 06:30:39 am
content: Quote from: Cubdriver on March 01, 2017, 06:16:57 amI see four foot stackable banana to banana Pomona cables for only $5.99 a piece on digikey. Am i not looking at the right ones? Seems affordable.

author: mtdoc
author_rank: Super Contributor
timestamp: March 01, 2017, 06:51:33 am
content: Quote from: JenniferG on March 01, 2017, 06:30:39 amThat's right. The Pomona plugs are great but I'm not crazy about the PVC insulated wire used in their test leads. I prefer silicone.You can get the Pomona plugs ondigikey for $2 eachthen make your own test leads with 12 gauge silicone insulated wire from Franky on eBay or from HobbyKing.

author: SingedFingers
author_rank: Frequent Contributor
timestamp: March 01, 2017, 07:05:33 am
content: The PVC is quite rigid on them but at least they stay put unlike the flappy silicone ones which turn into a spaghetti nightmare.

author: Cubdriver
author_rank: Unknown
timestamp: March 01, 2017, 07:06:31 am
content: Quote from: JenniferG on March 01, 2017, 06:30:39 amYup - those are the ones. I've found that some people think $6 a pop is obscenely expensive. Better to set low expectations.As mtdoc points out, they're a bit stiff with the PVC insulation, but since most of my stuff weighs a ton, it's not a huge issue for me. As he suggests, getting the plugs alone and buying silicone wire elsewhere then 'rolling your own' is certainly a viable option too. I may try that at some point in the future, but for now the somewhat limited flexibility of the premade ones doesn't bother me enough to do so.-Pat<edit- typo - iPads are teh suck for text editing in forum posts!!>

author: JenniferG
author_rank: Frequent Contributor
timestamp: March 01, 2017, 07:09:01 am
content: Oh wait pomona are pvc? Gah at that price thought i was gonna get silicone!

author: Cubdriver
author_rank: Unknown
timestamp: March 01, 2017, 07:13:56 am
content: <shrug> If you happen to place a Digi Key order for something, order a pair of them for $12 and see if you like them. I have a fair number of them, and we have quite a few in the lab at work, too. I'm happy with them and plan to get some more next time I order something...-Pat

author: Cubdriver
author_rank: Unknown
timestamp: March 01, 2017, 07:21:02 am
content: And as SingedFingers points out, they're less tangly than silicone leads. That's one thing about silicone test probes that annoys the crap out of me - the damned things seem to be self tangling. Sometimes I swear you can plug them into the meter and lay them on the bench and they'll twist themselves up in a minute or so, then need to be stretched out and have the Gordian Knot untangled before you can make a measurement.

author: BU508A
author_rank: Super Contributor
timestamp: March 01, 2017, 07:26:22 am
content: Have you had a look at Franky's store? He is one of the forum members here.http://stores.ebay.com/99centhobbies/https://www.eevblog.com/forum/buysellwanted/franky's-sales-thread/

author: 2N3055
author_rank: Super Contributor
timestamp: March 01, 2017, 07:29:25 am
content: I personally like softer PVC cable types best. I had a set of fancy (and expensive) Fluke modular probe cables and hated them with passion. They were too soft, always tangled, and they have stickier surface than PVC so the don't slide.. I could never had cable to stay in any place it was good for me...I gave them as a present to a friend, and bought other cables... The trick is that cable has to have very fine copper strands and have decent gauge. Rigidity is more defined by softness of the copper than insulation.I found some speaker cable that was ok, and good banana plugs (i like using spade connectors on PSU side) and just made a bunch..

author: SingedFingers
author_rank: Frequent Contributor
timestamp: March 01, 2017, 07:37:22 am
content: Pomona win always for me:1. stacking2. same leads they sold 30 years ago so no new lines or quality worries.3. banana plugs dont wear out or get loose4. tangle free wire5. easy to get hold of in UK (Farnell)6. never had a single faulty cable in years of use.7. really strong.8. massive range of products including BNC adaptors at same quality.9. only damn banana plugs that universally fit in anything flush.10. lots of pretty colours. purple ones are nice

author: mtdoc
author_rank: Super Contributor
timestamp: March 01, 2017, 08:14:01 am
content: Quote from: SingedFingers on March 01, 2017, 07:05:33 amHorses for courses.Actually newer Pomona leads with softer PVC are fine, I just prefer my spaghetti silicone soft not al dente.What I hate though is aged PVC that gets stiff. I have some very old Pomona leads that are almost rigid.

author: JenniferG
author_rank: Frequent Contributor
timestamp: March 01, 2017, 08:15:03 am
content: I'll try out the Pomonas now. As a starting set for PS does 4 feet sound good or three? Gonna get red black.. What color is standard for neg voltage?

author: SingedFingers
author_rank: Frequent Contributor
timestamp: March 01, 2017, 08:22:35 am
content: I use black for "common", red for "+volts", yellow for "-volts" and green for "earth".4 feet is plenty. I use 2 feet usually with a couple of 4 feet ones.

author: Cubdriver
author_rank: Unknown
timestamp: March 01, 2017, 08:38:01 am
content: Quote from: JenniferG on March 01, 2017, 08:15:03 amThe ones I have are three footers, and I need to get some that are longer. With the way I have things stacked on the shelf above the bench, 3' often seems to be juuuuuuuuuust a gnats whisker too short and I need to move something. If you expect to be mostly working with everything on the same plane (like flat on the table, no shelves), then 3' leads are probably fine.-Pat

author: mtdoc
author_rank: Super Contributor
timestamp: March 01, 2017, 08:41:53 am
content: That's another advantage of making up your own - custom lengths!

author: nfmax
author_rank: Super Contributor
timestamp: March 01, 2017, 09:14:51 am
content: Quote from: Cubdriver on March 01, 2017, 07:21:02 amIt is not widely known, but silicone test leads exist in a space of eleven dimensions, most of which are so tightly tangled up as to be undetectable, leaving only the familiar five.

author: Cerebus
author_rank: Super Contributor
timestamp: March 01, 2017, 03:27:41 pm
content: Quote from: mtdoc on March 01, 2017, 06:51:33 amSomeone, it might even have been you, was saying this before. I piped up and said something to the effect "Oh, come on, it can't be that bad" and they responded by posting a photo showing them holding a plug pointing towards the ceiling while they held the cable a couple of inches back from where it enters the plug. That's stiff.

author: SingedFingers
author_rank: Frequent Contributor
timestamp: March 01, 2017, 03:31:00 pm
content: I like a stiff one

author: Cerebus
author_rank: Super Contributor
timestamp: March 01, 2017, 03:39:26 pm
content: Quote from: nfmax on March 01, 2017, 09:14:51 am"Up, sideways, forwards, time and 'what did I come into this room for?'" or "Up, sideways, forwards, time and Murphy"?I'm the other way to some here. I find that silicone leads arelessprove to tangling, and easier to untangle when they do. I suspect that it's down to technique - I've spent so much of my life reeling up mike cables and the like that I can reel up a cable and put in the necessary 1/2 twist that makes it lie flat without even noticing I'm doing it.

author: bitseeker
author_rank: Super Contributor
timestamp: March 01, 2017, 07:40:11 pm
content: I have Pomona leads in 2-, 3-, and 4-foot lengths. Most of the time, I'm using the 2' or 3'. It all depends on how far away your stuff is and/or how much current you're going to put through them.Although the Pomono PVC is al dente, it's not too bad. Holding one 4" from the banana plug, it'll bend 90-degrees from its own weight. It's not silicone, but it's not bad. Sometimes it's helpful as a slight twist will make it hold a curve around or over other stuff on the bench.The best thing about the firm insulation is when twisting leads for noise rejection. They stay together nicely without wire ties.

author: mtdoc
author_rank: Super Contributor
timestamp: March 01, 2017, 07:44:08 pm
content: Quote from: Cerebus on March 01, 2017, 03:39:26 pmYeah, maybe that's it. I spent years coiling climbing ropes with the same technique.

author: mmagin
author_rank: Frequent Contributor
timestamp: March 01, 2017, 07:55:40 pm
content: I recommend a cable holder (the comb-shaped metal things) up high enough to hang everything up. Though for really long stuff it works better to throw it over something by its midpoint.

author: SingedFingers
author_rank: Frequent Contributor
timestamp: March 01, 2017, 08:30:47 pm
content: Indeed. Mine just hang over my pile of crap

author: JenniferG
author_rank: Frequent Contributor
timestamp: March 01, 2017, 09:15:27 pm
content: Quote from: mmagin on March 01, 2017, 07:55:40 pmThanks, I have a 3D printer and have seen that people have made STL models for these already. I'll probably print a couple of those