Scope power cord - Page 1
Forum section: electronics / general

author: Skypilot
author_rank: Newbie
timestamp: April 17, 2017, 10:26:23 pm
content: Newbie here.Just ordered an Ebay scope without power cord. Are the all the same? Is there a NEMA code known for obtaining one?

author: cvanc
author_rank: Frequent Contributor
timestamp: April 17, 2017, 10:32:15 pm
content: What scope did you get?Any reasonably modern scope will take what's called an "IEC" power cord. It's exactly the same type that most computers use. One example is shown here:https://www.monoprice.com/product?c_id=102&cp_id=10228&cs_id=1022801&p_id=5279&seq=1&format=2If you got a much older scope it might have something more rare, but the vast majority of them just use the good old generic IEC cord.Welcome to the forum and have fun with your new toy (oops... tool!).

author: Skypilot
author_rank: Newbie
timestamp: April 17, 2017, 10:56:59 pm
content: Hey, thanks for that (reply). I got a cheap, disposable old HP 2212A. The idea is if I blow it up, no prob.

author: Monkeh
author_rank: Super Contributor
timestamp: April 17, 2017, 11:15:42 pm
content: Quote from: Skypilot on April 17, 2017, 10:56:59 pmErr.. that's not a scope.

author: helius
author_rank: Super Contributor
timestamp: April 17, 2017, 11:34:41 pm
content: Quote from: Monkeh on April 17, 2017, 11:15:42 pmIndeed. TheTektronix 2212is a scope, though. If working, they are worth something, not a junk toy like a Telequipment or Eico. Don't blow it up.

author: james_s
author_rank: Super Contributor
timestamp: April 17, 2017, 11:46:25 pm
content: All of the Tek scopes since at least the mid 70s use a standard IEC (computer type) power cord. Ideally though you want one that has a right angle socket and a plug that has a cord clip molded in. That way you can leave it connected to the scope and wrap it around the cord storage pegs when you put the instrument away. If it's always set up on the bench though that doesn't really matter.

author: tautech
author_rank: Super Contributor
timestamp: April 17, 2017, 11:50:36 pm
content: Quote from: helius on April 17, 2017, 11:34:41 pmErrr what ?Telequipment was good enough to be bought by Tek and continued trading as Telequipment as a division of Tek.Tek learnt how to do modular construction with the likes of Telequipment's D83 that came before Tek's modular 500 and 5000 mainframes. D83 was my first scope, it had an excellent and large display with a very crisp trace that I have not seen equalled in a CRO and was a pleasure to work on. But like most old instruments a PITA to to keep operative and had a fair bit of rework before I was happy with reliability before selling it.5" CRT, 50 MHz and delayed dual timebase made it a very good scope for the mid 70's.

author: james_s
author_rank: Super Contributor
timestamp: April 17, 2017, 11:56:15 pm
content: It could be the reliability that gave people a bad taste. I don't think Telequipment was very common in the US, I never saw one, but Tek scopes are legendary for being rock solid. I still have a 465B that is nearly as old as I am and it has never given me any trouble. I just pulled it out the other day to try it with a time domain reflectometer I built and it works great. A bit of a pain to count the divisions and calculate by hand though, I've been spoiled.

author: tautech
author_rank: Super Contributor
timestamp: April 17, 2017, 11:58:52 pm
content: Quote from: james_s on April 17, 2017, 11:56:15 pmMy D83 was already 30+ years old when I got it.

author: james_s
author_rank: Super Contributor
timestamp: April 18, 2017, 12:02:50 am
content: Well, beats me then. May just be unfamiliarity with the brand, or confusion with a similar sounding low end brand. Like I say, I've never seen a Telequipment scope in the US, I'm sure there are a few around but it's not a brand I'm familiar with until now.

author: tautech
author_rank: Super Contributor
timestamp: April 18, 2017, 12:09:37 am
content: Quote from: james_s on April 18, 2017, 12:02:50 amThat's not surprising but they were more common in the commonwealth countries. IIRC D65's were more common but not of modular construction and because of that one might imagine much cheaper and affordable.There's a few members on the forum that still have a Telequipment scope in use.

author: helius
author_rank: Super Contributor
timestamp: April 18, 2017, 01:27:57 am
content: I see I've ruffled some feathers. Fine, delete "Telequipment" and put "B+K". Whatever.

author: Monkeh
author_rank: Super Contributor
timestamp: April 18, 2017, 01:29:28 am
content: As the proud owner of a D75 which has found a new way to fail within ten minutes of me fixing it every time I've touched it, I do not feel ruffled.

author: tautech
author_rank: Super Contributor
timestamp: April 18, 2017, 01:36:40 am
content: Quote from: helius on April 18, 2017, 01:27:57 amNot at all.Just sharing some info for the benefit of all.James learnt something.We all have less than ideal experiences with many things we own that can unfortunately give us a mindset about a brand, good or bad but sometimes prematurely and unjustly.

author: Cyberdragon
author_rank: Super Contributor
timestamp: April 18, 2017, 05:32:54 am
content: Quote from: james_s on April 17, 2017, 11:46:25 pmWhat do you do if you are the proud owner of a pre-70s tek scope? One with seemingly the smallest recessed standard US male plug. One so small that when you ask almost every hardware store they are like "we don't have any female ends that small".But hey, when you get it for $5... *sticks cord through unused hole and solders it to inner plug terminals*...who needs plugs...I mean really.

author: Shock
author_rank: Super Contributor
timestamp: April 18, 2017, 10:51:19 am
content: Don't buy a power cable over the internet from China, go to a local computer store and ask for something decent.There is made properly in China, but the internet is saturated with poorly made in China ripoffs.

author: james_s
author_rank: Super Contributor
timestamp: April 18, 2017, 03:44:35 pm
content: Quote from: Cyberdragon on April 18, 2017, 05:32:54 amWell the 531A I recently passed on to a fellow eevblog member had a standard NEMA plug on the back, I always just used a single end grounded extension cord as a power cord on that. The plug stuck out the back though and was not recessed. If yours is recessed then I dunno, I'd be tempted to modify it and install a standard IEC jack.

author: Cyberdragon
author_rank: Super Contributor
timestamp: April 19, 2017, 12:01:18 am
content: Quote from: james_s on April 18, 2017, 03:44:35 pmI would if it wasn't literally sticking a square peg in a round hole. Do they even make connectors that mount into round holes?

author: Ampera
author_rank: Super Contributor
timestamp: April 19, 2017, 12:09:01 am
content: Quote from: Cyberdragon on April 19, 2017, 12:01:18 amDINAnd I came up with an idiotproof cheap, and compact socket/outlet concept that was round.

author: james_s
author_rank: Super Contributor
timestamp: April 19, 2017, 12:24:19 am
content: Well they used to, but they aren't very common anymore. I've seen power cords for the recessed NEMA-15 jacks and they look like a regular extension cord end only round. While I generally avoid modifying equipment, it's pretty easy to use a nibbler or file to enlarge the hole and make it rectangular to mount a standard IEC jack.

author: Cubdriver
author_rank: Unknown
timestamp: April 19, 2017, 04:54:59 am
content: Quote from: james_s on April 18, 2017, 12:02:50 amI *think* that Telequipment was what we had in high school in my electronics shop, but I'd need to dig out the ancient notebook containing the lab report with the drawing I had to do of the front panel to say for certain. Lord only knows wherethat'sgone off to in the intervening 3+ decades...I'll have to look - my curiosity has been piqued.-Pat

author: Cubdriver
author_rank: Unknown
timestamp: April 19, 2017, 04:57:47 am
content: And as for NEMA 5-15 power cords for Teks with recessed jacks, I've simply gotten regular (though relatively short) three prong extension cords and whittled the female ends with an exacto knife as needed to fit into the connector on the scope.-Pat

author: james_s
author_rank: Super Contributor
timestamp: April 19, 2017, 05:00:38 am
content: If you have a belt or disc sander it may be possible to get a reasonably nice round profile on it.

author: NiHaoMike
author_rank: Super Contributor
timestamp: April 19, 2017, 06:13:02 am
content: Did anyone expect this thread to be about Agilent/Keysight scopes and their oddball power cords?If a standard PC type power cord is what you're looking for, hunt around in your stash of cables before buying anything. There's a very high chance you'll have a bunch sitting around unused.

author: vk6zgo
author_rank: Super Contributor
timestamp: April 19, 2017, 08:27:22 am
content: Quote from: tautech on April 17, 2017, 11:50:36 pmThe Tektronix 500 series was well established before that company bought Telequipment in the late 1960s/early '70s.The general opinion among most of my acquaintances at the time, was that, rather than than Telequipment becoming better following the buyout, some of their flakiness found its way into mainstream Tek stuff.We tended to shy away from anything Tek labelled as "Made in Guernsey".

author: Rerouter
author_rank: Super Contributor
timestamp: April 19, 2017, 10:11:55 am
content: I have just recieved a TM503 with one of those cables if your still after it, as i'll have to replace it for an AU one,

author: David Hess
author_rank: Super Contributor
timestamp: April 19, 2017, 03:15:48 pm
content: Quote from: james_s on April 17, 2017, 11:46:25 pmThe Tektronix cords with the right angle IEC connector and cord clip are better than any of the modern replacements I have been able to find though. Modern cords are much thicker and the clip was molded directly into the plug gripping really tight like the cords on the old Hoover vacuum cleaners.

author: rdl
author_rank: Super Contributor
timestamp: April 19, 2017, 04:48:42 pm
content: I've looked off and on for a right angle IEC/NEMA 5-15 with the cord going "down" (toward the ground connection) instead of to the "side" (inline with the hot/neutral) but have had no luck. The Rigol DS1052E seems to have been designed for this type, but mine came with a standard type that sticks straight out to the left and is always in the way.

author: David Hess
author_rank: Super Contributor
timestamp: April 19, 2017, 06:33:52 pm
content: These are the cords I tried which are the only ones I found with a right angle IEC and a clip but they are too large in diameter and the clip barely works. One is 2 meters and the other is 3 meters.http://www.mouser.com/Search/ProductDetail.aspx?R=17506_10_B1virtualkey68600000virtualkey686-17506http://www.mouser.com/Search/ProductDetail.aspx?R=17507_10_B1virtualkey68600000virtualkey686-17507

author: james_s
author_rank: Super Contributor
timestamp: April 19, 2017, 06:47:29 pm
content: One has to wonder why they bother molding a cord clip into the plug that is too small for the wire the plug is molded onto.

author: David Hess
author_rank: Super Contributor
timestamp: April 19, 2017, 08:09:49 pm
content: Quote from: james_s on April 19, 2017, 06:47:29 pmThe clip is not too small for the cord's wire; it just hardly grabs it so it twists lose way too easily. In practice when wrapping the cord around the guides on the bottom of the oscilloscope, the clip does not work at all. The cord's clip was just badly designed.The cord's wire is thicker, 5/16" versus 1/4", than the original Tektronix cord so it will not fit on the storage guides when it is wrapped up.

author: james_s
author_rank: Super Contributor
timestamp: April 19, 2017, 10:23:54 pm
content: Does Tektronix still sell the cords? They were used on a lot of instruments. If they do I suppose they probably want 10x a reasonable price for such a thing. Power cord is not exactly a fancy new technology, you'd think everyone making them would have that nailed by now.

author: David Hess
author_rank: Super Contributor
timestamp: April 20, 2017, 12:29:28 am
content: Quote from: james_s on April 19, 2017, 10:23:54 pmIf Tektronix is selling replacements for their own power cords, it is a well kept secret. I am sure they would be happy to sell you a complete oscilloscope.Every once in a while I look for good replacements but so far I have found nothing. Maybe there is some law or regulation forbidding winding power cords up for storage or including clips on power cords.

author: james_s
author_rank: Super Contributor
timestamp: April 20, 2017, 01:05:39 am
content: Tek does sell parts, I inquired about the BNC connector with readout coding pin as used on Tek probes and they quoted $16 which is not unreasonable for a custom part like that, dunno what shipping is going to cost though. Look in the manual for your scope and I bet it will list a part number for the power cord.

author: Martin.M
author_rank: Frequent Contributor
timestamp: April 22, 2017, 07:43:43 am
content: source: Tek Manual, 7854greetingsMartin

author: james_s
author_rank: Super Contributor
timestamp: April 23, 2017, 01:16:30 am
content: Unfortunately those are not part numbers, just option numbers that you can specify when ordering a scope.

author: Cubdriver
author_rank: Unknown
timestamp: April 23, 2017, 02:30:17 am
content: As far as older Tektronix gear with recessed NEMA 5-15 style male connectors for AC Mains input, as I mentioned earlier I get a standard NEMA 5-15 extension cord and do the necessary surgery to make it fit. In most cases this entails simply slicing off the nub that is normally present on newer extension cords on the side opposite the ground pin opening of the socket. I assume that this nub is present to prevent people from inserting the plug 180 degrees off with its ground pin winding up alongside the receptacle rather than entering the hole it's meant to go into. (It's sad that people are that stupid, but I've little doubt that preventing that from occurring is why the nub is there)Here are photos of the one on my 575. (The cord is a 1' long one purchased from McMaster-Carr for Tek scopes on carts where longer cords would leave a lot of excess wire to deal with.)Plugged in:Modified and original receptacle end:Alternate view:-Pat

author: Martin.M
author_rank: Frequent Contributor
timestamp: April 23, 2017, 11:23:51 am
content: hello Pat,Tek made also some cables where the NEMA is also round and fits exactly in the plug.greetingsMartin

author: tooki
author_rank: Super Contributor
timestamp: April 25, 2017, 01:33:17 am
content: Quote from: rdl on April 19, 2017, 04:48:42 pmTake a look at these adapters:https://www.amazon.com/POWER-ADAPTER-SOCKET-DEGREE-Wall-mounted/dp/B00S0O42TI/http://www.ebay.com/itm/New-IEC-C14-Male-to-C13-Female-Power-Adapter-Plug-UP-90-Angled-Supplied-for-TV-/222092159586?hash=item33b5b96a62:g:H0sAAOSwg3FUmQy1https://www.amazon.com/dp/B072KZM5FB/This page lists the directions canonically (and seems to agree with other suppliers):http://www.stayonline.com/connector-plug-angles.aspxYou seem to need a "C13 up". Googling for "C13 angle up" led me to these, among others:http://www.stayonline.com/detail.aspx?id=25897https://www.warehousecables.com/cgi-bin/commerce.cgi?preadd=action&key=WC540815

author: rdl
author_rank: Super Contributor
timestamp: April 25, 2017, 04:27:32 am
content: Up angle, eh? Sure enough, that's exactly what I've been wanting. Thanks for the info.

author: Monkeh
author_rank: Super Contributor
timestamp: April 25, 2017, 04:30:00 am
content: Yep, you can get C13s in the full set of up, down, left, and right angle. You'll pay for it, but you can get 'em.StayOnline there aren't cheap, but I've used them before, quality seems okay. They'll make pretty much anything you like to order if they don't already stock it (no up or down angles to order, though, guess they don't have the moulds).

author: bsalai
author_rank: Regular Contributor
timestamp: May 15, 2017, 06:52:22 am
content: Quote from: Rerouter on April 19, 2017, 10:11:55 amDo you still have this? A friend gave me a 491 spectrum analyzer circa 1966, and it would be perfect for that.BradSent from my iPhone using Tapatalk