Tektronix Scope - Expert Opinions Please

[Kazooman]

I am looking for a good used scope. What do you think about this one on ebay?

Thanks for any advice you can offer.

http://www.ebay.com/itm/130620452691?ss ... 1438.l2649

[Phil_S]

OK, not an expert....Tek is the "Fluke" of o-scopes. A good deal for a calibrated scope.

What exactly do you intend to do with it? You see, for what we do on tube amps, a 20MHz scope will do very nicely. If you have other intentions, well, that's a clear game changer.

For that money, you can by a lesser scope, but it's new and carries a mfg warranty. Here's an example of a 100MHz scope for $399 plus shipping, http://www.tequipment.net/RigolDS1102E.html

Do you really want to pay that much for an older model used scope on eBay? If you just want one for guitar amps, you can get plenty of scope for $100.

Just my 2¢. Good luck.

[67plexi]

Back in the day that was a high end scope still is.

I'm sure it has more gold on the boards than the cost of the unit.

To bad the stock probes are not with the deal.

[Kazooman]

Thanks for the response.

The first use I'll have for a scope is adjusting the heads on several Echolette tape echo units that I have been restoring. I have some very good information from Bobby Staedel in Germany about this. The problem is that the oscillator runs at about 60KHz. I have a pretty good (vintage) volt meter that is supposed to be able to handle that, but I just don't really trust the readings I get. The other use for these echos will be to try to trace down the source of some distortion that is introduced somewhere in the signal path (even straight through without the tape).

I have seen many lesser or comparable scopes on ebay and other places, but I don't know how well I can trust their calibration. I don't need another meter I can't trust! At least this guy seems to know what he is talking about and he has a good reputation in his feedback. The scope is returnable with no questions asked for a period and warrantied for 30 days. From what I have seen a fully calibrated copy of this scope usually sells for much more.

[loctal]

Make sure to factor in the price if you need to buy a probe!

[LeftyStrat]

Make sure to factor in the price if you need to buy a probe!

+1. It can be a shock to buy a cheap used scope without probes and then find out you'll spend more than the scope on probes.

I have to agree with Phil, if you're going to spend that much, get a new digital scope. It's one of those things that you'll wonder how you ever got along without it.

But on a budget, you should find plenty in the $100-200 range for tube amp work.

[LOUDthud]

The seller seems to know what he's doing and has the equipment to properly cal the scope. What tends to go wrong with these scopes are the switch contacts and the pots. The pots are sealed, sometimes you can take them apart and cleanup an intermittentcy. Tek made most of the switches. The contacts can sometimes be replaced if you can find them. Many times the PCB has gold plating that serves as one side of the contact so to really fix it long term, you have to re-plate the gold. Some Tek scopes have switching power supplys. I'm not sure about this model. That eliminates most of the aluminum electrolytics. A scope with linear supplys will have electrolytics that will be hard to find if they need replacement. If you plan on using one of these long term, you should definately consider getting a second one (non-working is ok) to use for parts. The CRT will be one of the hardest parts to find. Usually they last a long time but get dim with age.

[rdjones]

That's a whole lot of scope, and easily worth the asking price.
It's absolute overkill for audio work and a few generations older than I would recommend for someone looking for a first scope.
Without the proper probes it's not really a 350MHz scope.

Teks are great scopes, for that price range or less I'd be looking at something newer with a larger display like the 22xx series, or TAS series that have built in digital metering.

I have a 2215 60MHz that I got at a HamFest for just over $200.

rd

[Kazooman]

Thanks to all for the good advice.

I didn't know about the issues or repair if something went wrong. Very good to know.

I have looked around for newer digital scopes that would meet the needs for amp repair, but didn't find anything that didn't cost a fortune. I read about the Tek 485 in an old post on a forum and that's how I came across this one on ebay.

I guess I need to keep looking. My requirements are (1) reliability and calibration, (2) adequate bandwidth, channels, controls for audio work, (3) price. Note that I was just about willing to spring for the scope I mentioned. Something in the $200 - 300+ range would be great.

Does such a scope exist?

[selloutrr]

It's a pain in the ass to read on my phone so if this has been pointed out please ignore my post.

Tektronics is top quality. However, like any used or vintage piece of test gear. It will need to be calibrated and serviced before it's trustworthy. Getting a used unit from an auction can be hit or miss, some will work and only need to be calibrated other will need a complete over haul.

Calibration has 3 levels:
1. You have the tools and know how to do it yourself, it's not perfect but it's good enough for hobby.

2. You send it off to a lab to be calibrated. Add shipping both ways plus the calibration fee. If the unit has any issues they will contact you and give you an estimate for repair, plus the cost of calibration. if you refuse work they still charge you a minimum fee for bench time and often the calibration fee.

3.) same as number 2 with the additional fee of certified calibration which states it's accurate to whatever percent. this can be used in the court of law.

Since most of the development of tube technology and how they are used in a circuit is no longer relavent to today's technology outside of tube audio. a 20Mhz dual scope is more then enough band width.

IMHO if you don't do tech work for a living, already own a flag ship model Fluke meter (s), Tube tester and send your equipment out to be regularly certified/calibrated. Your money would be best spent on a new production scope with a warranty. I own 6 scopes, 2 teks, 2 HP, and 2 cheapies I picked up on close out at Fry's for $75 each. I can afford to blow up throw away and buy 3 cheapies for the cost of getting one HP or Tek calibrated. ALL 6 are the same accuracy for tube amps.

[Structo]

It says below the description that for a $500 BIN you will get two new probes.

[husky]

I am looking for a good used scope. What do you think about this one on ebay?

Thanks for any advice you can offer.

http://www.ebay.com/itm/130620452691?ss ... 1438.l2649

I like the 465B

[ApexJr.]

+ 1 for Husky ... I too like the 465B
100Mhz and a bigger screen.
The 453 and 485 scopes are small screens whereas the 465B
is a larger screen and has been around a long time and a great
scope. Don't get a 465 or TAS465 earlier versions.


Steve @ Apex Jr

[gktamps]

I bought a used, uncalibrated 485 for $175, and two used TEK probes for $60. I was able to see the scope in operation before purchasing, but it had no warranty. $500, calibrated with warranty and probes is pretty good, but as others have said, a newer, less expensive scope might be better?

[Bob S]

Back in the 70's the me & my workmates used to fight over who got to use the Tektronix 475 DSO - but we were dealing with pre processor electronics. Mostly TTL, CMOS, A/D & D/A chips.
These days I use an old Hitachi dual channel 100MHz scope or a Fluke 123.
With the Fluke a simoultaneous on screen digital readout of AC & DC voltages is a definite advantage. Depends on how far you want to go I suppose.
With an older model make sure you get 10x probes to measure the voltages we get into.
I got my Hitachi for $100...
Good Luck,
Bob