Christmas Tektronix 2465 gamble 

Nice acquisition, Bob! My weakness is DVD Recorders, and reel to reel tape recorders. When I was a technician in the eighties, our Tektronix scopes were sent out for calibration every 6 months. The scopes were needed to set up the multipliers, and 7400 series troubleshooting the laser scanners we manufactured. They were controlled by a Z80 microprocessor! High tech at the time.

Fine unit there. I have 2445, 4Ch's 150MHz. Got it for almost free, I payed only the shipping costs 20 bucks. Case was, RIFA cap was exploded inside. Otherwise the scope is now very good and works a charm.

Hi Bob, Happy New Year! EDIT: After looking at your scope in the video, you may not have to worry about the issues I listed below, as your scope is a 2465, not the 2465A/B model. The cal data is stored in a EAROM chip, which doesn't have the internal battery. I think it's more like an early EEPROM. I will leave the info for the "A & B" model scopes below, just in case another viewer has one of those models, however, it doesn't apply to your model. ;) A few comments on the 246xB series scopes: These are very reliable scopes with one issue; they use an internal NVRAM chip that contains an internal battery in order to retain the calibration and configuration data. These NVRAM chips have a limited shelf life and quite often will fail after about 7 to 10 years as the battery goes flat. If it fails, you will get a checksum or other error at power-up. Sometimes you can click through the error and have limited use on the scope and sometimes it won't work at all. It just depends on what part of the memory gets corrupted. If you have a fully functional scope, it would be a good idea to remove the NVRAM chip and back up its contents to your PC, using a cheap PROM burner. Most of the ones you buy on eBay will read and write to them. The NVRAM chips are still available and you can then write a new one if the current one fails. You can't really calibrate one of these if you don't have the proper calibration equipment, so you would have to send it out or it will be a boat anchor. Last, there is an upgrade you can do to replace the battery-based NVRAM chip with a compatible flash memory chip. I even was able to find the chip mounted to an adapter board that just plugs in place of the original chip. I did this with my 2467B with great results. Unfortunately, I didn't back up my 2465 and the chip failed, leaving me with a boat anchor. There is a person that I have used in the past that will re-calibrate and replace the NVRAM in these, but he and the shipping are really expensive. I hope this helps. Best Wishes, Tony (XrayTonyB)

I was VERY lucky and paid $150 dollars for a 2465b from Israel and it got here in good condition, fully working. They even through in a probe for free with a little smiley face on the bag 😂. It can sometimes work out really well

Wow Bob, that fix was surprisingly easy! It is nice to have the newer test equipment but, fixing it can be a real challenge with all the custom parts that are used. A company I worked for 12 years ago wanted me to fix some of their HP-8657s but, kept running into custom ICs and sealed RF modules that were orginally assembled in a clean room, With no source of replacement parts, since most all companies now only want to offer replacement parts on units they currently build, owning a older obsolete model is risky.. At home, I have a Tektronix 465 scope, it has a mystery logic IC that went bad that controls horizontal sweep. I have tried to reverse engineer the part so I could build one but, it's a long term, low priority project. I noticed some of you past videos deal with repairing old equipment so, I need to tale a good look at those to get some ideas. The last RF signal generator I bought (2 years ago), was a URM-25. Being tube powered, most all the parts are readily available.

Bob, you've become a real scope-a-holic, a connoisseur of scopes. Enjoy your new toy in which most of the fun is in the fixing.

Thank you for the excellent video ! I repaired my friend’s 2445 which had the same problem and solution. I also made note of that EEVBlog. Thanks again ! Happy New Year !!!

The 2465 is considered the Cadillac of analog scopes. I have one, and it has done more for my hobby than any other device I have. The one I have, unfortunately, has a bad ground in it somewhere. A tap or two resolves this, but the gremlin moves... It also sounds like a hoover when it's running. I still can't think of being without it.

As a chemist who owns a Tek 2445 with Option 05, (TV Sync), it is fascinating how working that beam find button in and out dozens of times had practically NO effect. I make an assumption that those type of slide contact swotches have two little beryllium-copper (4-96) “kisser” leaves in the moving part that slide from the centre and front contacrs when out, to the centre and rear contacts when in or depressed. Generally oxide buildup is not a problematic as SULPHIDE buildup which forms much more tenacious insulating coatings…particularly if the contacts are silver plated as sulphur is a favoured ligand for silver-I! These type of intermittants never fail to “amaze and amuse” its almost utter lack of reaction to mechanical stimulus, but it closing circuit buy itself when utterly undisturbed, “just when it FELT like it” . When You very first powered it, I screamed at the screen, “The bloody beam finder button is stuck!”. I reckon that spray had either hydroxylamine or hydrazine in it which instantly reduces the sulphides back to the metal and flushes the sulphide ions out of there as hydrazinium sulphide. Great little score and nice easy fix, you fall in love with the cursors pretty quick! Mine had a Rifa go up in smoke st first turn on, on 240 here in Tasmania and the Ch-2 BNC was broken from the hybrid because with option 05 this is the input with the black level clamp…and I reckon it was from a TV station. Fixing the broken loose BNC was an Absolute Pain, what I thought would be a five minute fix with a blob of solder ended up being a MAJOR dissasembly and getting that whole bottom analog board out…and when I got it all back together…the black level clamp no longer worked baecaus I had plugged something from the option 05 board, (which tucks in down from the top between the tube and the power supply) in the wrong spot..and havn’t had the tome to track it down becsuse I’ve been eating far too much Christmas Cake! A mate has this exact 465, 300Meg model, slso with option 05, and his black level clamp does not work either! So when I fix mine, I’ll go do his straight after!

I fixed several from this era at a local university around 2005-15. The internet was a goldmine of info because I'd never opened one before then.

I love the Bandersen happiness mumbles..."Fade this and wow it mumble...mumble...mumble...HA HA!" Looks like a Happy Oscilloxmas!

Nice! Great scope and a simple fix! Happy New Year Bob!

Wow, so glad you could get it fixed, it sounded promising from the start with that beam finder switch!

The infamous RIFA caps are actually paper capacitors. They fail like the paper capacitors you have in a radio, except worse because they are often connected to power even when the equipment is powered off.

One precaution I would certainly put time and effort in, Bob, is to replace any and all RIFA capacitors inside the machine BEFORE you put it to daily use. Most RIFA's are located on one or both powersupply modules (2A in my 2445 scope). Also, I would advise to replace the (large, 220µF 250V ?) filtercaps of the powersupply as well. Replacing the caps is a rather straightforward process, provided you tease out the powersupply boards first. Nice score man, I'm slightly envious right now LOL Good luck and lots of fun with it :)

Now that is FUN👍 Happy New Year. Leo.

Can't go wrong with a Tek scope. The number one issue is a lack of use hence dirty controls. Second issue is calibration. Nothing you can't handle Bob. See Tony' B.'s comment below . After inspection and a helpful hint on the beam finder it is working fine. You did good all around . Great oscy for your shop! Happy New Year Bob.

Congratulations Bob! Thats a neat scope and it turned out to be just a matter of using some DeOxit on the switch! Im sure youll get lots of use and enjoyment out of it.

Nice instrument and I am glad it was an easy fix especially for an instrument that was made the year I graduated High School. I have the same weakness for test equipment as you. In the early years of my career, I used a lot of the 465 series Tektronics scopes. For a birthday present to myself in 2020 I bought a 475. We also have a fairly new Rigol on our bench but for a lot of measurements the Tek is my go-to scope since it is a pure analog instrument, and I am very used to using that type of scope. An old school engineer I worked with in the 1990's had an interesting perspective on analog vs digital. He viewed analog as being the truer representation of the signal and refered to digital a series of snapshots. Have a wonderful New Year Bob

Congratulations on a great purchase. I have a 2465B and took a chance also to land a great scope just a few months ago and have a lot to learn about how to use it.. Love how you found info and with just cleaning one switch, Have an awesome scope. My tech friends tell me these are " Much coveted " among techs. Looking forward to seeing it in action in upcoming classes.

Bob great Christmas present and lucky you. Great find nice scope. I hope I can get lucky this year. Really appreciate you video along with the new series on Basics on TV repair. thanks so much.

Excellent find and glad it was an easy fix!

I kind of lucked in to one of these base models a bit over a decade ago. In my case the power button was entirely unresponsive and the power switch had some arcing that kept it from working. You figured out all the advice I was hollering at the screen on your own, top marks for building a solid intuition. The manual has the details on the limits of channels 3 and 4, but basically they're either 4V or 0.8V full scale. I think they just didn't have the room or budget for four channels worth of frontend. Also useful is the 50Ω termination option on the first two channels. Worth verifying they're in good shape as they get roasted sometimes. There's a repair testimony PDF I found years ago on a site called Condor Audio. Just checked, it's still there, right at the end of the Projects list on the homepage. May be of interest.

Another great score, Bob! They're not the easiest to operate, but once you get used to it, you won't use anything else. I used one of these at work years ago - me and some dirty-minded colleagues used to make fun of the way the power-on indicator works 😂

I used to calibrate these scopes. Their biggest problem were the filter caps in the switching power supply.

I bought my Tek2465 in the mid-90s for the same reasons - used it for my master's thesis when it was new, couldn't afford it then, etc.. I paid 1200 for it at Haltek in SV, all calibrated etc, and it still works today, 30 years later. Good choice. Enjoy.

Nice scope. I can't remember what 24xx scope we used at my old job other than it was 2-channel. They were bulletproof and survived many field trips (they were always our carry-on luggage on flights.) We had 2-3 of them in the lab and I don't ever remember needing one serviced. The front cover option is important for travel. Never a problem with them. Only issue was if you were looking for some one-shot event you had to make sure the Weller soldering irons were nowhere near them. When their heater relay clicked, it would trigger any scope nearby. That should work well for you. I know you are not big on digital scopes. That HP was very crude by even late '90's standards. Heck the Teks at the time were about as bad. We evaluated several in the mid '90s and they were mostly expensive toys. Some Phillips model was the only one we found with decent one-shot performance. Always wanted a Tek scope with similar specs but never could justify the cost. Mid 2000's picked up a new Owan digital scope and never looked back. Looks just like many of the Tek scopes (they cloned the user interface) but was only 4" deep, so fits anywhere on bench. The on-screen measurements have freq, period, peak-peak volts, RMS volts and mean volts. Averaging to get rid of noise and increase resolution and peak detect would always allow rock-solid triggering on modulated signals or catch glitches. USB to PC app would allow FFTs and saving screens or sampled data or reference signals. Even that is crude by today's scopes. Unlike meters, dig scopes have RMS functions that handle AC+DC so could measure things like diode dropper heater strings. My 2 Fluke meter's RMS function are AC-only. I still have my dad's Leader scope that I fire up sometimes. Nice display and still works after 25 years. But the shelf on my bench is only 10" deep ;).

I have a Tektronix 2465 with several of the options. It is still my go-to scope even though I have 5 other scopes (digital and analog) to use. You can actually get a 1 GHz signal to display on the scope and read its frequency with the cursors. Of course the amplitude will be incorrect but the signal still displays. Channel 3 and 4 have limitations on measuring amplitude. You use the buttons to select either one of two scales for those channels. They have the full bandwidth.. The scope does have the auto detect feature for probes with the Tektronix BNC connector. It will detect both x10 and x100 probes and automatically set the amplitude settings to allow for correct measurements. I use the bag to store the probes and the user manual so they don't get "lost."

I'm a Proud owner of 2 of these bad boys, the 2465 no prefix models one of them lost the Tippler a few years ago, and I have been looking for the A9 HV board.... the board is good, but the Tippler is bad.... You should recap the inverter board and power supply and replace the Riffa Caps, but I'm late to the party, so I'm sure people have already told you that. Also keep an eye on your fan I had one go out on mine, and it got really hot before I noticed.... the Scope survived, but it was a close call.

Awesome grab! I would love to get a 2465/A. But those style switches are the worst! They are notorius for getting dirty and causing all sorts of issues. Almost everytime I have a piece of test equipment with a complex fault symptom, it turns out to be one of these switches. Most current example is a Tek 2230 scope I am working to restore (I am documenting it on my channel). It had a very strange fault symptom. As soon as you powered it on, it was immediately stuck in a calibration mode. Like the 2465 you have, the 2230 is a psuedo-analog/digital scope. But it also gives you the ability to capture and store waveforms. So anyway, it was not readily apparent like in your case what could be causing this fault. The calibration modes are buried in the menu select (i.e. you cannot trigger them with just one click of a button). So I checked all of the digital side cross-referencing the schematic and notated waveforms thinking it was some kind of strange digital issue (bad ROM/RAM, logic IC, etc) but nope... it was just one of these gang-style switches!! There's a bank of 5 of them that make up some of memory select options on the 2230. What really threw me off is that I've gotten in the habit of cleaning these switches immediately with contact cleaner on used equipment I acquire. So I had already cleaned these and still this fault persisted. In my case, the switch was copmletely dead - open on both poles (it is also DPDT) when depressed or not. So in short, ALWAYS check these switches first on old equipment you get. Just clean them thoroughly right off the bat or buzz them out with DMM. Otherwise they will send you down a rabbit hole especially if they are controlling digital stuff. Might be worth running thru the performance checks in the service manual, but this one looks like its operating great after that switch cleaning. Thanks for sharing and have fun with it!!

Congratulations! I have a 2445, almost the same thing. The problem with mine was the cooling fan bushings were dry - you were lucky with this one! Lubricating the fan bushings is much more difficult than it sounds, because of the funky blade mounting system (breaks easily), and the need to unsolder all the 12? coils, and disassemble the motor to reach the front one. Not impossible, but difficult. Use a heavy silicone oil or even grease on the bushings...

Oh My Goodness now the price of The 2465's Will Go Up. LOL Thankfully I still like my 54600B that I bought right after your video way back when before they went "Sky high" lol Still would like to get a PR-57 though. Happy New year Bob to you & yours.

Great result, there are bargains out there if you take a gamble, my scope was bought as not working, it was down to dirty switches & a couple of dry joints. Have a great 2024 Bob, looking forward to more excellent videos 🤓

Cool scope. I have a AN/USM 488, 2235 from the 80s. The Rifa across the line cap blew about the 3rd time I used it. Replaced it and the IEC filter receptacle and no problems since.

I have the exact same scope, also a gamble on eBay! Mine initially partially worked (one channel was dead), then it failed after an hour or two, looks like the digital +5v supply is malfunctioning, hopefully just a bad cap or diode. How about a 2465 restoration series of vids showing a recap of the power boards?

I absolutely love your videos!!!!!!!!!!!!!!!!!🤓

It’s a Christmas miracle! What an easy fix! I kinda want one of those, but I want to get a HP/Agilent 33120a or a 8657B. I have a Keysight scope that is pretty awesome! Nice find, fer sure.

I've bought more than 50 Tek scopes on eBay, most advertised as "not working, for parts" and only a handful of them have actually been non-functional. I got a 2465 DMS (ALL the bells and whistles) a couple of years ago for a really good price because it was advertised as non-working. It turned out to have a substantial dent in the case, and a loose cable from the digital board to the rest of the scope. After wrestling the case off and reconnecting the cable it worked perfectly. The 2465 is the best analog scope that Tek ever made, and even the first model (no A, no B) has a more than the advertised bandwidth (I've measured mine at about 400 MHz).

The 2465/A/B and the 2247A scopes must be the finest Tek scopes you can get. The 2247A also has digital measurements built in, such as true frequency, vpp, vrms, etc. Basically it HAS the math in it, but is an analog scope. The later A and B series have more measurement capabilities you wanted, depending on the options. My BDV has a frequency counter and on screen voltmeter as well. I am fortunate to own both a 2465BDV and a 2247A, which is a slightly nicer "Bench" scope. Another VERY good scope if you want digital and FFT, is the HP/Agilent 54622A/D and that series scope. (The one's with the floppy drive under the CRT, NOT the older one's) These scopes are in some ways still better than new digital scopes, especially for video/audio work. The CRT is "digital phosphor" and perfectly displays a video signal, the diamond pattern from a CD laser, X/Y, etc. It's the best "Analog" display I have ever used in a digital with the bonus of all the on-screen measurements. It is a fantastic every day bench scope. (Shamefully I have 4 of them..... 🤨) I have a Rigol 2000 series with all the bells, but it sits in the closet. The HP/Agilent is just way nicer to use. Bob, if you read this... pick one up and give it a test drive if the opportunity arises. You'll be very surprised how good it is for this type of work. I'd bet you'd be converted. 😉

OH! Whatever you do, the small front knobs are brittle as anything - if you must take them off, heat them well first and use no tools. They just pull straight off.

happy New Year The analog oscilloscope is great. If you ever plan to buy a digital oscilloscope, buy a 12-bit one.

Thanks!

I've got a Tektronix 2445a sitting on my bench waiting for a PSU recap and calibration :)

Congratulations on your score! Get a couple of 100X probes like Tek P6009. They have voltage ratings more in line with what is seen in tube circuits. If a 10x probe fails on a 400V circuit it could fry the input circuits in your scope. I have seen several 10x probes fail at less than 300V. Also watch for a P6015A.

Be wary of overheating the ICs with the cover off.

I would do as little to it as possible. Anything might mess with its calibration. It's a very complex device. Even the rifa is safe to leave in. It might blow, but it's rating is that it blows open, not short. It might stink for a while, but that's all. Most components will be high quality, even the caps and there is a reasonable chance they are all fine.

My suggestions: definitely replace the RIFA X2/Y2 paper capacitors. At this age, and knowing this scope hasn't been used for many years or even 1-2 decades, the RIFAs will turn into smoke bombs within a few hours of use. If the IEC power socket has an integrated EMI filter in it, that also might contain RIFA/WIMA paper capacitors. I would also replace the small electrolytics on the main board, they are 40 years old, 85°C, and right next to heatsinks. Don't bother replacing metal can tantalums, they cost a fortune, and almost never fail due to aging (but they are easily damaged by overvoltage). Definitely replace all dipped tantalums, if it has any of those. And as I always say, dump all the ROMs. This is a very common scope, so the ROM contents are quite surely available online, but I would still dump it, so you can be sure you have the right contents for your HW revision. I would like to get a scope like this so badly, but shipping and customs from the US to Hungary are cost prohibitive to me (often the seller doesn't even offer shipping to here). When these turn up for sale here locally (it's quite rare), the lowest price is usually about $400-500, up to double that, which I won't pay for a gamble.

The 2465 one of the best analog scope made, beside the 7 series mainframe scopes. but definitely do fan and heat sink mod and replace capacitor in PSU, HV, main board service it and if you get a , or B version down the road not the regular 2465 as those used a EEPROM you have to replace battery while keeping power to memory and replace battery as you will lose calibration data and to recalibrate is a pain as you need a voltage source and reference level signal generator with matching cable and takes a few hours. I know I serviced and calibrated 100’s of them over the years. It one of my favorite oscilloscope ever made by Tektronix to date. That one oscilloscope I know pretty much every flaw and how to resolve as seen it all with that model. Once serviced correctly and kept cool they are great and reliable. Yes replace all Rifa capacitors they will fail and leave a bad smell when they do. It a 4 channels which is only really a 2 channel as other two channels are limited.

It can happen... I've had it happen that it was just a bad line cord... or an intermittent line cord... or a bad, or tarnished pins on the C13 connector... a few time an electrically bad 'power on' switch (or a bad mechanical connection, if the switch is mechanically isolated.) ... or the switch has broken inside. Usually we are told to start troubleshooting by verifying proper power supply voltages... but, IMO it pays to make sure you have power, and it can get to where it is supposed to go. Sometimes by passing a switch can reveal it is intermittent. IMO, replacing blown fuses, without knowing why they blew, is a bad idea... and I never bypass them. (except to check continuity.)

Channels 3 & 4 are much more limited than 1 & 2. They are only switchable between 0.1V and 0.5V per division and they are only DC coupled with 1MΩ input impedance.

Channels 3 and 4 have limited attenuation (two levels, .1 V/DIV and 1V/DIV? It says on the front panel), but you can have them all on screen at once. The advice in the manual is that Channels 3 and 4 are meant to be used as external trigger sources.

Not sure if these are the same, but with my 2430 they tell you to only run them for a short time with the cover off. Those hybrid modules heat up pretty quickly and can be destroyed otherwise. But regardless, a nice example of this 'scope. I used to wish back in the '80s I could afford one. Still check once in a while to see if one comes up for only a couple hundred dollars or so, but working examples seem to command $700 or more. Not willing to pay that for a 35 to 40 year old 'scope.

It l00ks good.

IMO, you can never have enough scopes!

Do we know the difference between a DS0 (digital sampling oscilloscope) and a 'digital oscilloscope' ... maybe not.

I wish my TDS420 had a simple problem like this, not 30+ leaking surface mount electrolytics.

Those early digital sampling scopes were really bad at finding intermittent glitches... the older analog scopes' phosphor delay picked up glitches easily. I still dislike even vastly better modern scopes from this formative experience...

I wouldn’t have just plugged it in and hoped for the best. At minimum, I would check across Live and Neutral to make sure the thing wasn’t one, big dead short (or open)!

@bandersentv, Its hard to believe it soon will the New Year 2024 and that 1984 is 40 years ago.

I remember using one of those in vo-tech in the 80s, also just curious, were you able to meet your Christmas deadline for the customers sets, might there be an RCA video coming to patreon? It's like watching a cliffhanger 😬👍

Bought a 2465A in a company auction for $10. Works fine except every time at power up - it displays a "VOM Communication Error". This for is the optional meter that is often attached on top of the scope but is no longer on mine. Fortunately, that error message goes away after a few seconds. Would be nice to get rid of that error - anybody know how to tell the scope that the meter is no longer attached?

Where's Shango Dan , ? change all the capacitors, put it on shelf call it a queen

wow

My scope only does 20mhz not sure if can do radio alignments with it. Costed 40$

what all can these be used to test, a local guy has one for sale $175. I'm tempted to buy it but I'm just learning electronics at near 58 years old .

First! Hope you had a great Xmas Bob...do you still use your HP digital scope?

Milk the front panel controls.

Wait you work a job? confused