Want/Need Oscilloscope/Please Help!

[The Ballzz]

Hi Folks,
I've come to the point where I really think I need an oscilloscope for testing and working on tube amps! I ONLY need it for tube amp purposes and don't believe that it needs a lot of bells and whistles and advanced capabilities/functions.

Not knowing or remembering the ins & outs of it's usage, I don't know what the different specifications mean or what is actually needed for my intended purposes. I need a unit that is simple to learn how to use and from what I can gather, the capabilities required for tube amp work are not very elaborate and should not be too terribly expensive.

If anyone here would be willing to point out some units for me to look into and help me get started, I would be eternally grateful.

Thank You,
Gene

[xtian]

You're correct, needs are minimal for tube amp repair. A 20MHz or better used scope can be had for under $100 on eBay. Make sure it comes with probes.

You also need a sine wave generator, but that can be your smart phone.

[John_P_WI]

Gene,

First question is: How much are you willing to spend?

I will caution you to a few points, in the last 20 years I have gone through 4 analog scopes that I have either been gifted or bought for less than 50 dollars. While they have worked, they are a source of frustration. Used probes suck, you can spend a lot of time chasing problems that turn out to be the probe itself. Cheap probes suck, new good probes are expensive and will dwarf the cost of a used analog scope.

My Leader scope, will not ac trigger any more and the Hitachi won't keep the trace still (plus "rotates" the trace off of horizontal as it warms up), combine this with probe troubles and you are in for a frustrating experience with older equipment. The good thing about cheap older scopes is that they are great to learn on and if you blow them up... oh well.

Things to look for: 20 Mhz is enough for tube audio, 2 inputs / channels, GOOD 10x probes, triggers effectively etc, GOOD Probes - can't say that enough.

Something newer should prevent some of the frustrations that I spoke of above. Look for a good used scope like a Tektronix 2213, 2215, 2225, and others in the 2XXX series.


If I have any money left after taxes this year, I think I may buy a digital scope (like the one linked below) for my solid state bench... **** Note, I have not evaluated the specs of the scope for tube use - Would need to use a 10x probe for sure and probably a "blocking cap". Being that I'm an analog scope guy, maybe someone else can chime in regarding the newer cheap digital scopes for use with tubes... The one advantage that analog phosphor displays have is the "dithering" or smoothing, cheap digital scopes can look "blocky" sometimes especially with lower resolution displays. ****

http://www.tequipment.net/Rigol/DS1054Z ... AiI08P8HAQ


Good luck, you will use a scope more than you would ever think... Hope I didn't muddy the waters too much with my ramble.

John

[Leo_Gnardo]

Have a look at Fair Radio in Ohio. All sorts of surplus goodies. I got my Hewlett-Packard 122AR scope there some 30 years ago. All tube, it's needed a little attention 3 or 4 times, nothing a tube amp guy like you couldn't figure out. Probes? Nothing fancy necessary. I use a 5 foot length of Belden 8410 coax, banana plug on the scope end, gator clips on the other. I don't much worry about biga-ziga-gigahertz response, dealing with audio. Scope has an incredible (small) 200 kHz bandwidth. These days you can find better, faster, digital readout scopes for a couple hundred bucks at most, that would put my old jalopy to shame. No matter, HP gets the job done. And so can you.

[romberg]

maybe someone else can chime in regarding the newer cheap digital scopes for use with tubes...

I recently bought a Rigol DS1052E. Someone here mentioned them and I had been meaning to pickup a scope. For me it works great.

My only other use of scopes was in electronics and physics labs back in college. I still remember the frustration with adjusting the old analog scopes so that they would trigger correctly. My Rigol has a lot of features. The best one is the large friendly "Auto" button. You press it and it just works. So, you can spend your time debugging your circuit instead of fooling around with scope controls.

Mine came with a set of 300V 10x probes. These work ok for signal level parts of tube circuits. But at some point I may wanna poke around on plates and other areas. So, I bought a set of 100x 1000V probes. These set me back around $75. You can spend alot more on probes rated over 300V. Some of these probes cost more than a scope!

To me the extra cost (over an ebay used bargin) is that I did not have to deal with ebay, it is new and it is plug and play simple to setup. Worth the money to me.

Mike

[John_P_WI]

Thanks Mike, maybe I can join the Rigol club later this spring...

[martin manning]

Anybody laid hands on one of the low-cost (~$500) Tek scopes?

[The Ballzz]

Honestly,
I've been kinda hoping that some here might offer me a reasonable deal on their "begginer's, entry level" unit that they've upgraded from. At least it would be from a trusted source, as opposed to a less than scrupulous ebay seller who may have simply "band aided" a unit with bailing wire and duct tape to get the screen to light up!
Thanks All,
Gene

[Ron Worley]

Anybody laid hands on one of the low-cost (~$500) Tek scopes?

Martin,

Yes, I got one this year. Although I hear that the Hantek is identical and cheaper. At any rate, it's very nice- light, small and accurate.

As such, I now have 2 tektronix analog units to sell- a 465B with the attached DM44 DMM and a smaller 422 unit.

[Aurora]

Make sure that max input voltage, typ. 25-50V, times a 10 probe is enough to look for noise at B+ of at least 500V. Otherwise, a x100 probe may be necesseary.

[The Ballzz]

Anybody laid hands on one of the low-cost (~$500) Tek scopes?

Martin,

Yes, I got one this year. Although I hear that the Hantek is identical and cheaper. At any rate, it's very nice- light, small and accurate.

As such, I now have 2 tektronix analog units to sell- a 465B with the attached DM44 DMM and a smaller 422 unit.

Ron Worely,
I sent you a PM. Please let me know if you're interested in helping me out! Price, condition, etc.

Thanks,
Gene

[martin manning]

Anybody laid hands on one of the low-cost (~$500) Tek scopes?

Yes, I got one this year. Although I hear that the Hantek is identical and cheaper.

I don't quite understand how that works. Any idea (anybody)?

[sunnydaze]

A little while back I got one of the low priced Tek EDU scopes. Like Ron said it's small, very light and accurate. There are a lot of free lessons - these are their educational units designed for classroom use. RS electronics ran a sale and I went for it - similar price to the Rigol and other Chinese makes. Figure Tek will probably be around a long time and would be better value in the long run.

I think the thing is great.
Mike

[The Ballzz]

EEEY-HAH, I WON!
Just got a fair deal on a Tektronix 2215A from flea-bay and it will be here soon! It is not coming with very much in the way of probes, so now I need to address what I need to get in hand for when the scope arrives.

Can anyone here suggest a reasonably priced probe set for this particular unit for use with tube amps? I would like to be able to test for issues in the power supply as well as signal testing. One thing that confuses me is the MHz ratings of different probes. do I need probes to match the MHz rating of the scope or do I need them to be appropriate for my intended testing procedure?

The Learning Curve Begins
TIA,
Gene

[Structo]

I like the probes here.

www.Probemaster.com