Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => AmpTools/Tech Tips => Topic started by: Tone Junkie on February 27, 2017, 01:19:42 am

Title: time for oscilloscope
Post by: Tone Junkie on February 27, 2017, 01:19:42 am

Tired of tracing issues thru my test amp.Time to step up and finally get one any recommendations. Having read a lot from you guys I know, or I think any way I need 100HRZ with test probes . Theirs a lot on fleabay but  a little point in any direction would be much appriciated.
Bill
Title: Re: time for oscilloscope
Post by: shooter on February 27, 2017, 08:34:14 am
Any scope under a hundred pounds  :laugh:

what uses do you envision, just troubleshooting amps?, maybe digital equipment?, do you want to "spec" out things?  look at complex timing circuits?

2 channel with 1 regular and 1 HV probe is a start, anything beyond that is a bonus, make sure you can find, get/find the operators manual for whatever you decide.
Title: Re: time for oscilloscope
Post by: Ed_Chambley on February 27, 2017, 02:02:24 pm
2 Channel to me is very nice.  I had a Tek on loan and then was offered a 2440 Tektronics for a very nice price.  You really do not need one this expensive.  I have a frined with a 2 channel Iwatsu that he got for $70.  It is a Iwatsu ss-5705. 

Ebay link for one:
http://www.ebay.com/itm/like/172429235502?vectorid=229466&item=172429235502&rmvSB=true (http://www.ebay.com/itm/like/172429235502?vectorid=229466&item=172429235502&rmvSB=true)

Does more than he needs, much more.

It will change your life troubleshooting.  I cannot imaging not having one now, but the one I got has a LOT of bells and whistles.  Don't get me wrong, as I learn to use them they are of benefit, but I never really use anything on a Tube the Iwatsu cannot do and do very well.  What I would look for is one that recognizes a 10x probe and adjusts to the probe.  This is only a problem with DC coupled.

And of course, you can shop here for some nice used test gear.
http://www.theoscilloscopeshop.com/iwatsu-oscilloscopes.html (http://www.theoscilloscopeshop.com/iwatsu-oscilloscopes.html)

BTW, Iwatsu is not a cheap brand per say and seem to be well made.

Good luck on your search Bill.
Title: Re: time for oscilloscope
Post by: Tone Junkie on February 27, 2017, 08:45:54 pm
Thanks gentleman . I just want to trouble shoot amps nothing complex . but when tracing a noise its mighty nice to zoom in on it quickly.
Bill
Title: Re: time for oscilloscope
Post by: shooter on February 28, 2017, 08:38:40 am
Quote
tracing a noise its mighty nice to zoom in on it quickly.
Unless it's everywhere! :icon_biggrin:
Title: Re: time for oscilloscope
Post by: Ed_Chambley on February 28, 2017, 10:05:12 am
Quote
tracing a noise its mighty nice to zoom in on it quickly.
Unless it's everywhere! :icon_biggrin:
If it is everywhere, then you just start over.
Title: Re: time for oscilloscope
Post by: timbertoes on February 28, 2017, 10:41:05 am
I bought an Owon from selig in new york.  The shipping and customer service from Selig was fantastic.
Title: Re: time for oscilloscope
Post by: shooter on February 28, 2017, 08:27:42 pm
Quote
then you just start over.
but won't you windup where you started? :icon_biggrin:
Title: Re: time for oscilloscope
Post by: DummyLoad on March 01, 2017, 12:13:32 am
Quote
then you just start over.
but won't you windup where you started? :icon_biggrin:


only if insanity prevails...  :help:


--pete
Title: Re: time for oscilloscope
Post by: PRR on March 01, 2017, 01:53:38 pm
IMHO, 450KC (0.5MHz) is plenty for most audio and ALL tube guitar amp work.

Simplicity and practicality are MUCH more important. A well-loved beast from 1963 may be fine if you have the space. (OTOH a sick old 'scope is a bigger debugging job than any guitar amp.) Decently-made asian LCD jobs are now well under $300 new with probes and manual, and far smaller than CRT. I've had good service from an early hand-held with only 50KHz and 64-level display.
Title: Re: time for oscilloscope
Post by: DummyLoad on March 02, 2017, 01:23:37 am
low cost current production 20MHz CRT types are still available. IMO analog and CRT display are best for audio work.


click me.  (http://www.ebay.com/itm/gos-622g-GW-instek-20MHz-Analog-Oscilliscope-NEW-IN-THE-BOX-/371844480147)



--pete
Title: Re: time for oscilloscope
Post by: SILVERGUN on March 02, 2017, 11:53:02 am
This is a decent deal:
http://www.ebay.com/itm/Tenma-Test-Equipment-72-3060-20MHz-Oscilloscope-2-/322437821507 (http://www.ebay.com/itm/Tenma-Test-Equipment-72-3060-20MHz-Oscilloscope-2-/322437821507)
 
EDIT: when I calculated shipping it came to $67 dollars which is pretty jacked up and false, so be careful before hitting the 'buy it now'
Title: Re: time for oscilloscope
Post by: sluckey on March 02, 2017, 11:57:27 am
It's got a built in sig gen too! :thumbsup:
Title: Re: time for oscilloscope
Post by: Tone Junkie on March 07, 2017, 08:43:22 pm
What do I need to know about probes and buying them.
Thanks Bill
I really like that new one Pete.
Title: Re: time for oscilloscope
Post by: Tone Junkie on March 07, 2017, 08:48:55 pm
I guess I didn't read far enough that one comes with them.
Thanks guys you have been a huge help as usual.
Bill
Title: Re: time for oscilloscope
Post by: Tone Junkie on March 08, 2017, 03:37:22 am

I pulled the trigger on the new instek cant wait to get it.
Bill
Title: Re: time for oscilloscope
Post by: Ed_Chambley on March 08, 2017, 01:34:06 pm
Bill,
I have some very expensive ones, but after I saw this video I put my expensive ones away and only use them when needed.


https://www.youtube.com/watch?v=qBdA0KVct9g (https://www.youtube.com/watch?v=qBdA0KVct9g)


In the video he shows the difference between $9 probes and $450 probes.  For amp work the $9 work just dandy.  I will say the calibration is not as stable, but that is so easy to do and should be done anyway before using the probes.


I purchased a nice variety of different connectors from aliexpress.com,  check them against nice ones I have and they will pick up a very minimum amount of noise.  For the price of these things it is difficult not to get them.
Title: Re: time for oscilloscope
Post by: Tone Junkie on March 08, 2017, 06:36:02 pm
Thanks Ed Good to know.
Bill
Title: Re: time for oscilloscope
Post by: timbertoes on March 09, 2017, 07:19:50 am

I pulled the trigger on the new instek cant wait to get it.
Bill
nice, congrats :)