'Spoofing' a Tektronix X10 readout pin? - Page 1
Forum section: electronics / testgear

author: icon
author_rank: Regular Contributor
timestamp: February 25, 2014, 10:45:26 am
content: HiA Tek 2245A followed me home the other day. It came with two P6109 (fixed x10 attenuation) probes that have a 'readout pin' built into the BNC connector. Between the pin and ground is an 11kOhm resistor - the pin mates with a ring around the BNC connector on the scope and tells it to switch to 'x10' mode.It also came with two other 6109 probes *without* the pin. Has anyone come up with a neat way of fooling the scope into recognising a x10 probe? I have seen online a suggestion that simply shorting the ring to ground works, but that seems a bit brutal.ThanksJohn

author: amyk
author_rank: Super Contributor
timestamp: February 25, 2014, 12:09:48 pm
content: An 11k resistor is out of the question?

author: icon
author_rank: Regular Contributor
timestamp: February 25, 2014, 12:43:21 pm
content: Well yes, thanks - that had occurred to me. It was the 'neat' bit I was looking for - some genius re-use of a common household object to neatly hold a resistor in contact with the ring and the BNC ground sleeve with getting in the way and whilst being easy to remove if needed. Someone's bound to have come up with something - this is the Internet, after all.It would have been nice if Tek had included a 'x10 override' switch, but sadly this isn't the case.RegardsJohn

author: DC5AJ
author_rank: Unknown
timestamp: February 25, 2014, 01:35:10 pm
content: You can take a BNC female to male, on the scope side of the Adapter you can bend a small piece of spring steel, solder it to the BNC connector. On the other side of spring steel clamp you could solder a SMD 11K Ohm. It is a little tricky to get it nicely build, but it is a simple way to get a x10 Adapter.

author: SeanB
author_rank: Super Contributor
timestamp: February 25, 2014, 06:22:07 pm
content: Drill a small 0.8mm hole in the outer body of the unpinned probes and place a short copper wire in it and place the resistor ( smd) between that and the ground connection inside the probe body. that will look almost original.

author: commongrounder
author_rank: Frequent Contributor
timestamp: February 25, 2014, 06:32:04 pm
content: I've taken a rubber washer with a hole diameter the size of a BNC jack, and wrapped thin bare wire around it, toroid style. When it is sandwiched between the probe BNC plug and the sense ring on the scope, it shorts the ring to fool the readout. You could probably fit a 1/8 watt resistor in there using the leads, or thin washers, as contacts, if it has to be a specific resistance. Kind of quick and dirty, but mine has worked for years.

author: edavid
author_rank: Super Contributor
timestamp: February 25, 2014, 06:57:14 pm
content: Shorting the sense ring to ground is fine... the scope is designed to work that way.

author: icon
author_rank: Regular Contributor
timestamp: February 25, 2014, 09:25:04 pm
content: I think the toroidally-wound rubber washer is the winner, thanks. I've just checked and shorting it switches to x10, drawing ~1mA in the process.Hey, can't you get conductive rubber? Hmmm...John

author: i386
author_rank: Contributor
timestamp: December 10, 2024, 03:54:23 am
content: Late to the party but I recently took a stab at this. I’d been looking for a reason to try using my vinyl cutter to make masks for etching pcbs so I cobbled this together.

author: edpalmer42
author_rank: Super Contributor
timestamp: December 10, 2024, 05:26:20 am
content: As a cautionary tale, I have a LeCroy 9384L which also has a similar readout pin. I did some quick checks to see how the scope would react to various resistances. When I shorted the ring to ground, the scope locked up completely. My complete list of responses is as follows:Resistance Attenuation<=300 ohms Scope freezes470 10a ( Not sure what this means - 10 amps??)1K x501K5 x202K2 x54K7 x1006K8 x10010K x10>=15K x1I didn't bother to get more specific. If I need to I can repeat this in a more official manner.Bottom line is that it seems that each manufacturer uses their own rules for this feature.

author: squadchannel
author_rank: Frequent Contributor
timestamp: December 10, 2024, 06:27:22 am
content: https://w140.com/tekwiki/wiki/BNC_connector_with_readout_ringhttps://w140.com/tekwiki/wiki/Tekprobe_BNC_connector