Favorite Tektronix Scope

of the knob.

because

I never had a HP scope that I liked, or would use unless there was no Tek scope available.

Hmmm? I cannot imagine what you like about the 1741A, but different strokes for different folks.

Be very careful with that grey horizontal timing switch knob. HP cut two (or was it 3?) slots that each cover 175 (115?) degrees through the body of the knob. They did that so that you could see the light mounted on the panel through the knob. Well, when the switch's lubrication gets a little sticky, and you get a little enthusiastic (and lord knows the plastic is already at least 18 years old), you will snap those thin little bits of plastic, and your knob will be gone, and your scope will be unusable. Forget about gluing it, as there was barely enough strength with the virgin plastic.

We had dozens of that family of HP scope, and they all went into scrap because the knobs were unavailable.

Tektronix did the same thing with their horizontal knobs, but they knew enough about materials engineering to make the body of the knob out of aluminum, and make the grip surface of the knob out of plastic.

-Chuck

Still using the 275Mhz hp1726A that was given to me when I started working for HP in '83. I keep it covered when not being used, so it still looks like new. Perhaps some day it will crap out, and I'll try a Tek!!

I haven't seen that reliability is a problem with the 1726A. They go and go... Drift is a bad problem, the zero goes all over the place, and needs constant diddling. It is all but impossible to adjust so that the variable volts/division knob doesn't shift the zero (and have it stay adjusted). The horizontal time knob is a really bad problem, as I discussed in an earlier note. If you haven't taken your scope apart, and oiled that switch's shaft, and replaced the grease on the ball detent, I would strongly suggest that you do so. When the knob breaks, it is end of game. I strongly considered turning out the inside of one of the broken knobs, and making an aluminum version of the center of the knob. The 1726A I wanted to fix was a complete cherry otherwise. But, Tek scopes were so easy to find and so cheap, that I couldn't see any real point. Into the scrap bin it went.

-Chuck

The HP 130C was an excellent oscilloscope. It has been stadily downhill from there.

-- Many thanks,

Don Lancaster voice phone: (928)428-4073 Synergetics 3860 West First Street Box 809 Thatcher, AZ 85552 rss:

Please visit my GURU's LAIR web site at

Microdyne had shelves full of HP scopes, but most of the techs would grab one of the beat up Leader 508A scopes.

I've had a 545 (military version), and it was quite good, although it had some calibration issues that I never really got resolved. Most of the time, though, I just used my 475, up until a couple of years ago.

I got rid of the 454 (space reasons), and picked up an HP 54201D digital scope with logic analyzer-type triggering. Although I haven't needed the fancy triggering yet (though it would have been really helpful a couple of times in the past), the scope itself has now become my main scope.

It's good to 300MHz (though I rarely need anything that fast), and I find I'm using the on-screen measurement capabilities and storage abilities quite a lot. Of course, the 475 is still sitting right on top, and in fact I used it to fix a faulty input channel in the 54201D when I first bought it. But really, the 475 rarely gets turned on now.

Oh - the best part was that the 54201D only cost me $50 at a Ham swap meet...

-- Mark "I prefer heaven for climate, hell for company."

Oh, and servicing the HP 54201D scope was pretty easy. It came apart in obvious ways, and the boards were big, double-sided (not multi-layer), and gold plated. There were a couple of scary-looking custom IC's, but the problem in my case was just a burned-up 100 ohm resistor.

I eventually bought (rented and copied, actually) the operator and service manuals for it, from W J Ford, who were quite easy to deal with and had a

-- Mark "I prefer heaven for climate, hell for company."

Scrap? Surely a machinist could make a suitable replacement knob for less than the value of a good scope.

You obviously haven't hired a machinist lately. In pristine shape, the scopes were worth $75 tops, the machine shops charge $100/hour, 1 hour minimum.

I was going to do the job myself, but balked because even when I was done, all I would have was a bunch of scopes that no one wanted to buy. We had them (with the broken/missing knobs in the $15 pile at several hamfests, and they went nowhere.

-Chuck

"The HP 130C was an excellent oscilloscope. It has been stadily downhill from there. "

I agree.

Why do you think that happened?

TMT

And I imagine you'd already junked a few to use strictly as spare parts to fix the others?

Long ago I was given a summer job to repair a palletload of HP 1xx scopes. One had a bad power transformer, unobtainable. The rest just needed new power supply filter capacitors. They seemed like nice scope, within their limits. Not particularly fast or bright or DC stable, but okay for our biomedical lab. I think that one had an actual knob on the DC balance control, it was so shaky.

I know this sounds like faint praise, but there's just something about a scope without a fan, with nice big knobs that go click instead of clunk, and that need no bandwidth limit button to keep the FM-ROCk-101 from fuzzing up the trace.

The HP 175 was an impressive scope-- 50+ 6DJ8's, 50MHz bandwidth, and a super bright CRT. It just ran and ran up until 1995 when the TRANSISTORS in the power supply went bad.

Still use a Tek 475 as my main bench scope.

Have tried several 54xxx digital scopes, don't care for the yucky green or amber screens, or the infuriating menu structure, or the way they don't detect clipping.

I have several Tek 485's on the to-repair shelf. IIRC they have about six power supply voltages and if any one of them gets out of spec the whole thing shuts down. Then it's kinda hard to figure out which one went blooey first. Grrr....

That's just it, they all had the main knob broken. Some had the pieces intact, but broken, others had nothing.

All worked, and all had the usual HP problems with drifty vertical amplifiers, and easy to fool triggers. It wasn't worth fixing them. We also had dozens, upon dozens of tek 465, 475, 485...

The tek scopes flew out, regardless of condition, the HP's just sat.

-Chuck

May be relevant. When a plastic eyepiece on my father's WW I binoculars shattered I found a company that made an exact copy from the other eyepiece which I sent them. This was some twenty five years ago.

I don't know what the plastic was, possibly some form of Bakelite or Ebonite.

Mike

Sorry, I'm late to this thread but thought I'd add an opinion.

No, Spectum Analysers are useless for anyone outside the government or RF extremists.

What are the specifications of the one you have? Maybe I can save you grief by taking it off your hands with a preimuim bid since it is just a glorified scope?

P.s. You never answered if the Motorcycle engine you are selling is the one that came by accident.

No one can stop you doing that.

??? Er, they're extremely useful pieces of test gear for anyone involved in RF., even hobbyists.

It's a different thing altogether!

Barely a week went by before I deeply regretted parting with my spectrum analyser. :-(

Wow. Does it show you the improvement from cryogenically treated, oxygen-free speaker cables?

Roy Lewallen, W7EL

Interesting coincidence... I got a 545, complete with cart and probes, for free, several years ago. A bit cumbersome in my limited lab space in the basement, but the price couldn't be beat.

It finally died on me. I sold it for parts and bought a nice 465B (off the e-place, where else) that now sits on the same cart. What I got for the 545 bought me a copule of probes -- all's well that ends well...

-- Ron