View Full Version : Opinions on oscilloscopes...


mattsd
08-27-2011, 11:05 AM
I have been looking for a good oscilloscope for awhile now, I recently found a HP 1741A that's been fully calibrated and tested for $160, as well as a 1740A for $155, also fully calibrated. I've looked at a Tek 465B, which I know is well recommended on here, but I can't find much on the HP's. What are your opinions on the HP's? Are there any others that you guys can recommend?

AAA3330
08-27-2011, 11:24 AM
Tektronix would be my first choice as far as oscilloscopes go, but HP is generally high quality equipment also. I've seen more Tektronix scopes in the industry than anything else, but we also used a lot of HP equipment also.

Jon_Logan
08-27-2011, 11:44 AM
It depends.

I've seen lot's of Tek 465's and they range from good deal to do-not-buy.

You want to look at the trace. Is it bright, tight, and well focussed? That's king. Next make sure the trigger circuit works.


I like the old hp's too, but I had a 1740 where a vertical amp IC died. HP made the part and it's been NLA for >10 years..

Don't discount Hitachi, Kikisui, Leader, Panasonic, you can get great deals on those.

As far as the hp $150 for a 1700 series... Not for me too steep for the risk. A 465? .. ah, to me they're okay. I'm much more impressed with fresher scopes these days. If the 465 has any options, voltmeter, etc: that sweetens the deal. Does the dual sweep work on the 465?

BayouTiger
08-27-2011, 12:07 PM
I used to carry a Leader as a field Tech. We beat the hell out of them and they held up very well. Always liked the Tek's though. I now carry a Fluke 123, but have never looked at audio with it.

mattsd
08-27-2011, 12:35 PM
Lot's of suggestions already, wow! You guys have me making a list of manufacturers already. :D

You want to look at the trace. Is it bright, tight, and well focused? That's king. Next make sure the trigger circuit works.


The HP's and the Tek all have very tight traces and are bright and well focused. I didn't specify this and I should have, I'm looking for a 100mhz scope minimum. That what I would like to have, as I plan on using it for FM alignment eventually, but if necessary I'll go lower.

Jon_Logan
08-27-2011, 01:02 PM
100Mhz is good. 100MHz would be very helpful for viewing Digital disc RF waveforms (eye-patterns).

While 100MHz is useful for FM frequencies, 9 times out of 10 20MHz is fine because your looking at mostly demodulated audio frequencies. I've performed a lot of FM alignments and repairs and it's very rare that you're trying to use/need a 100MHz scope to look at the front end or IF strip. It can be problematic too. The scopes extra capacitance and resistance can detune a circuit when you probe. You need special equipment such as active probes or detector probes.

100MHz is great... ...the more the merrier, but I wouldn't use "FM alignment" as the driving force for wanting 100Meg.

Hyperion
08-27-2011, 03:33 PM
100Mhz is good. 100MHz would be very helpful for viewing Digital disc RF waveforms (eye-patterns).

While 100MHz is useful for FM frequencies, 9 times out of 10 20MHz is fine because your looking at mostly demodulated audio frequencies. I've performed a lot of FM alignments and repairs and it's very rare that you're trying to use/need a 100MHz scope to look at the front end or IF strip. It can be problematic too. The scopes extra capacitance and resistance can detune a circuit when you probe. You need special equipment such as active probes or detector probes.

100MHz is great... ...the more the merrier, but I wouldn't use "FM alignment" as the driving force for wanting 100Meg.

Words of wisdom :yes:

Jon_Logan
08-27-2011, 03:46 PM
Tanx Hyperion:thmbsp:

mattsd
08-27-2011, 04:29 PM
Thanks guys, you've given me a lot more options! I always thought you needed a 100Mhz to do FM alignment properly. As far as 20Mhz scopes go, what is the opinion on a Tek 2205?

ghazzer
08-27-2011, 08:18 PM
Look at this thread (http://www.audiokarma.org/forums/showthread.php?t=375486)if you need to know more about scopes.

You should be making a list of features that you need/want, plus a list of features that you don't need to pay for. Then you can evaluate each scope against your requirements, not what someone else suggested.

Start with what you want to do with a scope, and write it down. I'll bet that you won't come up with more than 5 things but it will help define what you should be looking for.

Listen to what Jon_Logan is saying. You can buy a fancy scope with loads of features and plenty of bells and whistles, then you can watch it spend some time in a repair shop.

Also: Think about why you need to have it calibrated (and why you want to pay for that). Most times when I use a scope I am looking for relative measurements, like left ch vs right ch, and not trying to measure a signal to three decimal points. Consider a scope with a built in "calibration signal", which is probably all you will need.

Good hunting - - -

.

mattsd
08-29-2011, 11:23 AM
Believe me, I'm listening. I have had no previous experience with oscilloscopes, I'm just going on what I have read and seen recommended. I have not been repairing audio gear for very long, but already I've found places where a scope would have been useful.

Dukiedook
08-29-2011, 11:23 AM
Also think about whether your scope can be worked on or not, a 465 and others made around that time are mostly made of caps, resistors and transistors that can still be sourced and repaired. You get into newer models that use IC boards and it blows, you have to find another board to fix it, not many repair options there.

Martin.M
10-04-2011, 03:03 PM
sorry, 465 is full of chips :D
the last true Classic was the 454A (150MHz portable, not one IC)

Tek.

2xx Mini Portable series, later models like 222, 224 complete SMD mounted
3xx early Portables series, most of them made in japan by sony/tek
4xx later Portables series, up to 454A the best table tek ever made, special the 453, 454..
5xx Classic Tek tube, greatful instruments what needs care.
6xx ( the 661 is only for people who are Collectors of Tek gear :-) )
22xx low cost portable / table series from Tek, allover to find
7xxx lab series with plugins, perfect, but not for beginners
11xxx high speed lab DSO series, oversized for audio / video

TDS ... modern plastic bomb, DSO for everyone, full smd

my Tip to get an low priced high quality Tekscope for Audio:

422 early model, up to 15MHz calibrated, not easy to kill his input stage, perfect for the most of all.
453 (not-A) the same, but 50MHz calibrated.
---------
453A 50 MHz, Fet Input. very fine Classic
454A the same, but 150 MHz

46x, 48x oversized, sensitive for overloading.

465 and others made around that time are mostly made of caps, resistors and transistors that can still be sourced and repaired.
When you have a Tek what needs repair, and you think you cannot help him, ask a person who knows how to make that. We have also the chips, not only transistors :)

greetings
Martin

http://img819.imageshack.us/img819/1713/17844008.jpg (http://imageshack.us/photo/my-images/819/17844008.jpg/)

I am a Collector of old Tek Scopes.

Tom Bavis
10-05-2011, 07:56 AM
Tek T900 series (921, 922, 932, 935) have flimsy controls and plastic case but are good scopes with a bright sharp trace. And are usually cheap. Like the 453, has no unique parts made of unobtanium.

Dukiedook
10-05-2011, 10:06 AM
Damn, so my 485 has IC's in it? Well, I haven't cracked it open or looked too hard at the schematic and it runs fine. Poop.

Martin.M
10-05-2011, 03:24 PM
when you never switch the inputs to 50 ohms, your 485 can have a very long life.
Yes, it have around 30 ICs.

specialidiot
10-05-2011, 03:46 PM
I've often thought about snagging a scope. I was a tech back in the day and loved the Tek 22xx series. I'd buy one of those in a heartbeat if one came by.