They say everyone remembers their first time: spring tipped probes - Page 1
Forum section: electronics / testgear

author: bitbanger
author_rank: Regular Contributor
timestamp: August 31, 2019, 12:47:08 am
content: Had a loaner R&S scope at work so I've been using their RT-ZP10 spring loaded probes (500MHz passives) for a solid two weeks now.I'm totally ruined. They told me I could have the scope "until you don't need it anymore", hah!Every probe I touch now feels like I'm poking a screwdriver at the board. Not only was the tip dia. nice and small (smaller than the probemasters I use at home anyway) but the probes themselves were nice and compact. Not to mention the spring...Anyone know if these are re-branded? Or suggestions for ~350MHz alternatives that don't break the bank? Big fan of the probe masters, but they don't offer anything sprung as far as I could tell.Cheers!.:edit 500Mhz not 100Mhz edit :.

author: jjoonathan
author_rank: Frequent Contributor
timestamp: August 31, 2019, 01:43:35 am
content: I hear you! It was Tek 1GHz spring-loaded probes that got me hooked (poked? also -- are the 1GHz 10x Tek probes really 20x probes in disguise, is that how they get 4pF?) but R&S ZP-10s are what I have right now. They are rebranded PMK probes:http://www.pmk.de/en/products/pml_high_z_probesKeysight whitelabels PMK probes too:https://www.keysight.com/en/pd-1661717-pn-N2873A/passive-probe-101-500-mhz-13-m?cc=US&lc=engUnfortunately that bit of knowledge alone doesn't make them cheap, but it does give you more ebay terms to save searches for. Good luck!Not everyone agrees with us that pogo tips are fantastic. The usual complaint I hear is that they are too weak to poke through oxide, but I've never had the slightest hint of that problem. I half suspect that these complaints stem from working on Tek scopes that spent half a century experiencing condensation in no-HVAC ham shacks next to the ocean, or something. I don't ever intend to do that, and if you don't either it probably won't be a problem, just be prepared: haters gonna hate.

author: bitbanger
author_rank: Regular Contributor
timestamp: August 31, 2019, 02:57:11 am
content: Ah this is priceless (well, to the tune of $400 a pop) info, thanks! In my mind sharing eBay comparable model numbers/search terms is akin to sharing your coveted fishing spot.

author: Stray Electron
author_rank: Super Contributor
timestamp: August 31, 2019, 03:42:13 am
content: The LeCroy PP-005 probes are spring loaded and come with both a silver (It looks like) and a gold tip. I think the PP-005s are rated at 500 MHz. I think the PP-003 probes are rated at 350 MHz but I don't know if they're spring loaded.

author: David Hess
author_rank: Super Contributor
timestamp: August 31, 2019, 03:53:43 am
content: Subminiature oscilloscopes probes used to be a lot more popular until the rating agencies got involved and there was no way they could meet the creepage and clearance requirements for the rated oscilloscope input voltages. That was about the time that binding posts were removed from multimeters and power supplies.They tend to be more fragile though.

author: jjoonathan
author_rank: Frequent Contributor
timestamp: August 31, 2019, 04:55:26 am
content: Wow, PMK really gets around! Whitelabeled by Keysight, LeCroy, and R&S. Not bad.The "silver" (steel?) tip is solid and the gold tip is spring-loaded. You get both, even in the basic accessory version. Needless to say, I keep the spring tips loaded in mineRe: creepage and clearance reducing the popularity of "subminiature" probes... really? I'd expect applications favoring small geometry to outnumber applications favoring high voltage safety rating by 10:1 these days, even more so going forward.

author: David Hess
author_rank: Super Contributor
timestamp: August 31, 2019, 05:15:43 am
content: Quote from: jjoonathan on August 31, 2019, 04:55:26 amTexas is another probe supplier which OEMs probes for other companies but only standard sized probes that I have seen.QuoteBut back when the issue came up, small geometries were the exception.The first subminiature probes I used were standard with the Tektronix TDS400 series DSOs and I really liked them. That was in the mid 1990s.

author: bitbanger
author_rank: Regular Contributor
timestamp: August 31, 2019, 05:22:09 am
content: FYI looks like the Lecroy PP-008 may be a more recent match, rated at 500Mhz as well.

author: 2N3055
author_rank: Super Contributor
timestamp: August 31, 2019, 11:51:03 am
content: Picoscope sells some that are quite decent.. You can actually get both pogo and solid pins as accessory so you can change them to what you need..

author: jjoonathan
author_rank: Frequent Contributor
timestamp: August 31, 2019, 12:27:34 pm
content: LOL, that makes 4, or if you count PMK itself, 5.Keysight:look at our 2.5mm 500MHz passive 10:1 probes and accessories!Pico:look at our 2.5mm 500MHz passive 10:1 probes and accessories!Rohde & Schwarz:look at our 2.5mm 500MHz passive 10:1 probes and accessories!LeCroylook at our 2.5mm 500MHz passive 10:1 probes and accessories!PMK:look at our 2.5mm 500MHz passive 10:1 probes and accessories!

author: RoGeorge
author_rank: Super Contributor
timestamp: August 31, 2019, 12:32:29 pm
content: Maybe put the PCB on springs, or on some insulator foam, and use normal probes?

author: bitbanger
author_rank: Regular Contributor
timestamp: August 31, 2019, 03:54:14 pm
content: Well I feel like an idiot because when they asked for feedback on the R&S I gushed over the probes. 🙄

author: bitbanger
author_rank: Regular Contributor
timestamp: August 31, 2019, 03:56:02 pm
content: Dumb question but what are the copper squares included in the accessory kits used for?

author: 2N3055
author_rank: Super Contributor
timestamp: August 31, 2019, 04:23:45 pm
content: Quote from: bitbanger on August 31, 2019, 03:56:02 pmYou stick them on top of chip case and ground them, so you have local ground for probing

author: jjoonathan
author_rank: Frequent Contributor
timestamp: August 31, 2019, 04:31:48 pm
content: They're worth gushing about, they're good probes!The copper squares make low inductance ground planes, e.g. by sticking them on top of a chip you are probing and soldering them to a few ground pins. Then you can rest the low-inductance bayonet ground connection on the low-inductance ground plane and browse with the tip. At GHz frequencies this technique is important for signal integrity, but I've always found it a gigantic ergonomic step up from trying to wedge the walking-stick ground between pins (or, worse, against a single pin) to get a decent connection, so I pretty much ignore the walking-stick grounds and use bayonet + copper pad whenever I can't use the inches long "antenna clip" ground. I went through the provided copper pads quite quickly and now I have a roll of adhesive-backed copper tape for the same purpose.

author: TheSteve
author_rank: Unknown
timestamp: August 31, 2019, 05:16:37 pm
content: The Keysight 1160a/61/62/63/64/65 line of probes include a pogo pin cap. They can be picked up for reasonable prices at times on ebay for the complete kit. They are long discontinued(and much nicer then the probes they sell now) and won't fit all scopes as the BNC body is larger. If you have an HP/Agilent/Keysight scope though they are the passive probe to dream of.