About to buy Tektronix 475.First oscilloscope so need price advice!

[belzrebuth]

Hi all,
I'm about to get a Tek 475 w/original probes and manual for about 150€ or 170$ (local pickup).

Seller says that the scope is working okay and shows pictures of it displaying two sines.
Traces seem nice and clear and the scope seems fairly clean.

I know the price isn't great (and not negotiable) but the guy's local and he will bring it to me so I'm thinking about it..

Should I pass and search for a 2235 or similar or I should just go for it?

I was considering a 465/475 mainly because these are supposed to be more serviceable than the other Tek scopes.

Thanks!

[EEVblog]

Why do you want and old analog scope as your first scope?
Modern digital scopes are much more useful.

[homebrew]

It pretty much depends on what you want to do with the scope.

15 years ago, I also bought a used analog scope of this area (Philips PM3216 - also my first one at the time) and still use it often today. It's just a handy tool to roughly look what is going on ... But at the time it was THE absolute eye-opener for me to be able to really "see" what was going on with my signals. With that tool, my enthusiasm of the hobby really skyrocketed ...

However, today I would certainly directly buy a DSO. Probably one of the Rigol ones, as they have exceptional price/performance and large sampling memories. These can be obtained at just nearly twice the price of your offer - so yeah, as you already mentioned, the offer is not really good, given the alternatives ...

[asgard20032]

When I was looking to get an analog scope, I wanted a good one for sure. So I looked up for tektronix 2465b and the like. Those scope has problem with the built-in battery, that keep the config ram alive (it is an analog scope, but with some digital feature). If you loose the config setup... Well, it is a fully  non calibrated scope. So if you really want an analog scope, either buy an older analog without any digital feature, but also less powerful, or be sure you know how to change the battery without loosing calibration, or how to calibrate it yourself.

Or just buy a modern scope, where everything work.

[belzrebuth]

I prefer an analog scope cause I like the crt screens better and I'm also going to use it for audio signals (synthesizers etc).
A lot of opinions floating that for audio you don't particularly need a digital scope,analogs are cheaper and well built and if they work they can perform just fine.

I like digital scopes as well (esp. agilent DSO2xxx) but these are going for more than I can afford right now and even 300-400€ for a low end Rigol is too much at the moment.

?nother reason is that analog scopes look better IMO.:)You just got to have one.!Although I agree that DSOs are much more useful and easier to use and maintain.

A DSO is definitely on my buy list this year after I save up for it and practice with an analog first.

I'm in Greece so US prices do not correspond to the EU ones for used scopes so I know that I should probably wait for something around the 100€ mark but I'm probably going to go with the 475 and just save for a DSO while learning and experimenting with what I have.

Seller will include a bunch of connectors and bnc cables so that might not be that of a bad deal.

I just want to make sure that the 475 is still a solid choice regarding analog oscilloscopes or I could really do better.


about that Dallas rtc chips there is a guide somewhere for replacing just the battery.
I've done it myself on a couple of old pentium I motherboards.
You just have to file down the chip in the correct spot to expose the CR2032 legs ; cut them and solder a battery holder on top of that.
Google it ;there's plenty of info on vogons.org.

[rstofer]

The Tektronix 4xx series scopes are excellent.  I have been using a 485 for the past 12 years and I don't plan to get rid of it any time soon.  I paid about $200 on eBay.  The price of $175 for the 475 seems right; I wouldn't quibble.

OTOH, I bought a Rigol DS1054Z a couple of months ago and it is now my go-to scope.  I wanted 4 channels with serial decoding and I was willing to give up bandwidth to get them.  The single-shot feature alone is worth buying digital over analog.

But if money is tight, a lot of electronics can be done with the 475.  You need to be a little more clever in coming up with ways to make patterns repetitive and sometimes you need to rig up a special trigger signal but there was a time before DSOs and, as I recall, we put 12 men on the Moon.  Just saying...

You will soon start to get advice that seems a lot like chasing this scope thing down a rabbit hole.  If you expand your budget to $400, the 1054 is excellent.  If you expand it to $1100, some other model is even better.  Heck, for about $150,000 you can get the top of the line.  I suggest you drive a stake in the ground at your budget and don't deviate.  You'll get a lot of advice like "... for a few hundred more ...".

But Dave is right, DSOs have features that make them much more capable than analog.  But sometimes, we need to take a step back and realize that this is a hobby, not a second career.  And this is the first scope, it doesn't have to be the last one.  In the meantime you can learn a lot about scopes and not break the bank.

Good luck!

[belzrebuth]

Very positive post rstofer !

You're spot on about people always wanting more without taking that step back and see that they really could get by with less.

That said,it's not that I won't buy a DSO at some point; it's that I prefer the nerdy feel of the analogs for my first one, and the money is really tight atm anyways.

Besides,if you're in for a digital scope you may really have to spend the extra buck if you want a little more longevity or extra features and that can indeed lead to greater dilemmas and expenses so I could postpone that until I have some dough saved.

I wouldn't commit to buy an inferior DSO just for not having some extra money but for analog I don't feel bad doing a similar thing (settling for not the greatest deal).
Maybe because analogs can't get any better anymore and I think that  475s were top class at their age.

Digital becomes obsolete faster ,although I think that for most hobbyists there are plenty of good value/performance choices these days.

Only thing I fear is that after cleaning the scope and everything I'll  need to educate myself on how I should test its accuracy and functions or worse even calibrate this thing!

I really wouldn't know where to begin if calibration is needed but I'm not touching anything until I get things straight,don't want to do more harm!

[tggzzz]

It pretty much depends on what you want to do with the scope.

That's the most important question, of course!

... as they have exceptional price/performance and ...

Who cares what the price/performance ratio of anything is? That's something marketeers dream up to convince PHBs (and preferably "upsell" to them!).

What matters is:

• does it do what I need it to do in my application?
• can I afford it?
• is there a significantly cheaper choice that will fulfil my needs?

[tggzzz]

Modern digital scopes are much more useful.

That completely depends on what you want to use the scope for.

If you are looking to see why your "digital"[1] circuit is operating intermittently, the 200MHz bandwidth of a 475 is a very significant improvement over a 50MHz bandwidth. Even 35 years ago, 100MHz was marginal for such purposes, and jellybean logic is faster now.

OTOH, if you are looking at startup transients, the bandwidth is relatively unimportant but the capture/storage is the key feature.

[1] it is an unconvenient truth that almost all electronic circuits are actually analogue, the common exceptions being femtoampere or photon counting applications.

[tggzzz]

When I was looking to get an analog scope, I wanted a good one for sure. So I looked up for tektronix 2465b and the like. Those scope has problem with the built-in battery, that keep the config ram alive (it is an analog scope, but with some digital feature). If you loose the config setup... Well, it is a fully  non calibrated scope. So if you really want an analog scope, either buy an older analog without any digital feature, but also less powerful, or be sure you know how to change the battery without loosing calibration, or how to calibrate it yourself.

True, but completely irrelevant in this case (a 475).

[oldway]

For audio applications, you don't need a 200Mhz scope, 20Mhz is more than enough.
In Europe, I think you better buy an Hameg analog scope (easier to repair if necessary) than a Tektronix one.
I think that something like an Hameg HM412 two channels would be a good choice for you.
I recently buy one for 40€ with probes for a friend of mine.

Hameg HM203 and HM204 are also good options.

My prefered Hameg analog scope is the HM605.

If you choose Tektronix, I recomand the 465B or the 2235.

Those old analog scopes don't have any ram nor built-in battery.

[tggzzz]

Very positive post rstofer !

Glad you've spotted that. The advice is sound.

You're spot on about people always wanting more without taking that step back and see that they really could get by with less.

A true engineering attitude

Only thing I fear is that after cleaning the scope and everything I'll  need to educate myself on how I should test its accuracy and functions or worse even calibrate this thing!

Make sure it really is working. Ask whether it has been "recapped" - electrolytics can degrade with age, and sometimes (not always) need to be replaced.

At the very least use a probe to look at the 475's calibration signal. You are looking to see both channels show a deflection on all ranges, and that you can trigger stably on all timebase ranges. The amplitude, frequency and risetime are not well defined, since the cal out is only intended to be used to trim *10 probes.

I really wouldn't know where to begin if calibration is needed but I'm not touching anything until I get things straight,don't want to do more harm!

You would download the manual and follow the instructions With a little understanding and imaginateion, you will realise you don't need the exact equipment specified...
To calibrate the x axis you need an accurate (i.e. <2% ) frequency source. Any cheap DDS is sufficient.
To calibrate the LF y axis you need a PSU and multimeter.
To calibrate the HF response you need a digital signal with risetime of ~1ns. I use 1 74LVC1G* gate, well decoupled, with short wires.

[tggzzz]

If you choose Tektronix, I recomand the 465B or the 2235.

The 465 does not have any advantages over a 475 - and the 475 has a higher bandwidth, which is important for some purposes.

[tggzzz]

I was considering a 465/475 mainly because these are supposed to be more serviceable than the other Tek scopes.

HP1740s and 485s are noticably better in that respect than the 465/475. I'm unpleasantly surprised at the construction techniques of the 465 and 475 - but that shouldn't stop you from buying a working 475 (or 465).

[belzrebuth]

@oldway
I very recently lost an auction for a 2230 which ended at 100 including shipping.
I didn't raise my max bid enough so someone snipped it from me
That was maybe the cheapest (listed as fully working) 22xx I saw the past month on eBay.(from EU)

I very much like the form factor of the 223x s but their prices often exceed my $$ limit.
I often see them go at about 200€ with or without shipping and most of them are listed without any accessories , "sold as-is" or "turns on" etc..

People seem to like them and they're popular so they seem to be going for higher prices than they're used to.
I think that 22xx series are the first that comes to mind when someone searches for an old scope on eBay.
US scope prices are much lower but I'd have to pay high shipping and tax fees so it's a no-go.

Unfortunately I can only shop from eBay because in my country you can't really find used scopes for a good price on the craigslist equivalent.

I was looking for Hameg too but Hameg scopes are also going for higher prices on eBay,maybe because EU sellers often list them so EU buyers consider them a cheaper (shipping-wise) alternative to Tek scopes.
They pop up on eBay (german) regularly for attractive starting bids but most end at about 150 or so and I'd have to pay about 25-50€ shipping so we're again at about 200.
Also most hameg scopes I see on eBay are 20mHz or 60mHz and the 475 is 200mHz.

I certainly don't think I need a 200mHz scope at this point but I don't think I could find a much better deal on a Hameg,except if I wait long enough and constantly check eBay listings.

@tggzzz

Thanks for all the tips!!
I really appreciate it.

I asked if the scope has ever been calibrated but the seller said it wasn't cause it worked okay so far so he didn't bother.
I know that's vague but that's all I know so far.
I also asked if he ever recapped it or replaced any components and guess what;
Yeah !
He didn't.

So I will probably have to check the state of filter caps and check voltages too.
I hope that since this is a working unit I won't have to mess a lot with it but who knows.
I think that I have to get one or two of these cheap function generators I see on eBay and just feed some signals in to see if everything shows as it should.

Asked the seller to bring a function gen with the scope in order to roughly check both channels before I buy it.

[tggzzz]

I often see them go at about 200€ with or without shipping and most of them are listed without any accessories , "sold as-is" or "turns on" etc..

If front panel lights are visible but a trace isn't, it means any/all of the HV, EHT, CRT are faulty, and maybe more. HV can be repaired, EHT and CRT are more problematic. If there are no lights then it might be only a faulty capacitor.

@tggzzz

Thanks for all the tips!!
I really appreciate it.

I asked if the scope has ever been calibrated but the seller said it wasn't cause it worked okay so far so he didn't bother.
I know that's vague but that's all I know so far.
I also asked if he ever recapped it or replaced any components and guess what;
Yeah !
He didn't.

So I will probably have to check the state of filter caps and check voltages too.
I hope that since this is a working unit I won't have to mess a lot with it but who knows.
I think that I have to get one or two of these cheap function generators I see on eBay and just feed some signals in to see if everything shows as it should.

Asked the seller to bring a function gen with the scope in order to roughly check both channels before I buy it.

You're welcome.

If it works, it works - and anything you do might make it worse. No surprises there. The easy check is to measure all the power supply voltage rails and the AC ripple voltages - both listed in the manuals. Poor caps often show up as high ripple. Tantalum beads often fail short-circuit, and that trips the entire PSU. There is a lot of information on how to choose replacement capacitors; search this forum and Yahoo! TekScopes.

If you know how to use a scope, having a function generator there will be a great help. You can regard the "cal out" as a very simple function generator, and even that will greatly increase your confidence.

[belzrebuth]

@tggzzz
Sadly I don't know how to use a scope (yet!) so I may have to read up a little tonight to be prepared!

I found a pdf online "oscilloscopes and how to use them" so I'll give this a go.

If you happen to have any recommended (mostly hands-on) references or YT videos on explaining basic oscope usage please share:)

I've watched a lot of YT videos these days tbh but I haven't quite grasped the whole concept of using a scope.

Of course having one nearby and get experimenting while reading or watching stuff would greatly help,I don't think you can really familiarize with these concepts otherwise.
Still though,any resources offered will be of great help!

[rstofer]

Very positive post rstofer !

Thanks!

Only thing I fear is that after cleaning the scope and everything I'll  need to educate myself on how I should test its accuracy and functions or worse even calibrate this thing!

I really wouldn't know where to begin if calibration is needed but I'm not touching anything until I get things straight,don't want to do more harm!

I haven't even taken the cover off of mine. 

I consider a scope to be a squiggly line display device, not a precision measurement machine.  The voltage scales are about right (actually, I haven't seen a measurable error) and the time/div seems right given that I usually know the frequency.  Realistically, the scope could be off a bit and I wouldn't be able to resolve it on the screen anyway.

If it displays both traces and the controls seem to work, I wouldn't be in a hurry to take it apart.

You can test all of the controls from the probe compensation source on the front panel.  You could also test it with a couple of batteries with known voltages.  If you get to test before you buy, why not brink along a 1.5V and 9V battery?

Squiggly lines...

[oldway]

If you choose Tektronix, I recomand the 465B or the 2235.

The 465 does not have any advantages over a 475 - and the 475 has a higher bandwidth, which is important for some purposes.

465 is simpler than 475 because 475 has two-non delaying sweep generators (A sweep generators) with complicated switching.
One sweep generator from 0.5 s to 1 µs/div and another sweep generator from 0.5 µs to 0.01 µs/div.

Replace parts of 465 are also easier to find.

[oldway]

See the prices of Hameg HM 605 on ebay.de :

http://www.ebay.de/sch/i.html?_nkw=hm605&_in_kw=1&_ex_kw=&_sacat=0&LH_Complete=1&_udlo=&_udhi=&_samilow=&_samihi=&_sadis=10&_fpos=&LH_SALE_CURRENCY=0&_sop=12&_dmd=1&_ipg=50

It is not as expensive as you say !!!!

And HM 203 is a lot cheaper.
Hameg has manufactured more than 300.000 HM 203...there is much luck to find one at a bargain price...

Most of Hameg's scopes have a "Component tester" that Tektronix scopes don't have and which is very usefull to diagnose and repair audio equipment

[belzrebuth]

I haven't even taken the cover off of mine. 

I consider a scope to be a squiggly line display device, not a precision measurement machine.  The voltage scales are about right (actually, I haven't seen a measurable error) and the time/div seems right given that I usually know the frequency.  Realistically, the scope could be off a bit and I wouldn't be able to resolve it on the screen anyway.

If it displays both traces and the controls seem to work, I wouldn't be in a hurry to take it apart.

You can test all of the controls from the probe compensation source on the front panel.  You could also test it with a couple of batteries with known voltages.  If you get to test before you buy, why not brink along a 1.5V and 9V battery?

Squiggly lines...

The transaction's going to take place at my house so plenty of batteries and a lovely Brymen DMM to check them,no problem with that.
I'm going to test it before buying.!

If the seller brings a function generator (as he said) we're going to test with that too.

I'm going to test as much as I can/understand and turn all the knobs.
Hope everything turns out okay.
Probably need to skim over the manual

[rstofer]

I haven't even taken the cover off of mine. 

I consider a scope to be a squiggly line display device, not a precision measurement machine.  The voltage scales are about right (actually, I haven't seen a measurable error) and the time/div seems right given that I usually know the frequency.  Realistically, the scope could be off a bit and I wouldn't be able to resolve it on the screen anyway.

If it displays both traces and the controls seem to work, I wouldn't be in a hurry to take it apart.

You can test all of the controls from the probe compensation source on the front panel.  You could also test it with a couple of batteries with known voltages.  If you get to test before you buy, why not brink along a 1.5V and 9V battery?

Squiggly lines...

The transaction's going to take place at my house so plenty of batteries and a lovely Brymen DMM to check them,no problem with that.
I'm going to test it before buying.!

If the seller brings a function generator (as he said) we're going to test with that too.

I'm going to test as much as I can/understand and turn all the knobs.
Hope everything turns out okay.
Probably need to skim over the manual

You couldn't get a better deal than testing the scope at your house. I'll bet it's going to work just fine!  The seller wouldn't be so helpful if the unit was junk.  It's a heck of a lot more comfortable than sending the money through PayPal to an eBay seller hoping that they ship something that doesn't rattle.

Go for it!

[DimitriP]

You couldn't get a better deal than testing the scope at your house. I'll bet it's going to work just fine!  The seller wouldn't be so helpful if the unit was junk.  It's a heck of a lot more comfortable than sending the money through PayPal to an eBay seller hoping that they ship something that doesn't rattle.

Go for it!

What he said.    Enjoy your "new" 'scope!.

[oldway]

Have a look if the fan is in good shape, it is difficult to find a new motor.

If it is in good working conditions, I think you will enjoy this oscilloscope.

[asgard20032]

When I was looking to get an analog scope, I wanted a good one for sure. So I looked up for tektronix 2465b and the like. Those scope has problem with the built-in battery, that keep the config ram alive (it is an analog scope, but with some digital feature). If you loose the config setup... Well, it is a fully  non calibrated scope. So if you really want an analog scope, either buy an older analog without any digital feature, but also less powerful, or be sure you know how to change the battery without loosing calibration, or how to calibrate it yourself.

True, but completely irrelevant in this case (a 475).

I was jut giving some advise if he decide to go with another analog scope. 475 is fine.