Measuring the 25V outputs off the trafo on my gainclone, I can get something that resembles a waveform, though it looks more like the matterhorn than a nice sine. I also tried sending a 500Hz wave through my system and measuring the positive on one of the input and output terminals, and it is picking up something, but I can't get it to look like anything recognizable.
Does the scope have "focus" and "astigmitism" functions -- you can twidle these as well.
If you short the probes together you should get a flat line. This scope also has a "ground" function on the vertical control panel -- if this is engaged and the line isn't flat then you've got a problem with the vertical amplifier.
If you short the probes together you should get a flat line. This scope also has a "ground" function on the vertical control panel -- if this is engaged and the line isn't flat then you've got a problem with the vertical amplifier.
I can get a square wave but it's very finicky and has a weird distortion at the right side- see the pictures attached below. The effect is a little hard to capture on a still but these should give a sense of how it looks. I can move it around and the amplitude doesn't change but if it moves much away from the center it loses definition completely.
With the inputs set to "GND" I can't get a flat trace- I get a sawtooth-like trace as seen in my earlier picture a few posts above.
With the inputs set to "GND" I can't get a flat trace- I get a sawtooth-like trace as seen in my earlier picture a few posts above.
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Well, just got back from New Hampshire (lovely day for a drive) with an Iwatsu SS-5710 4ch 60MHz scope which was verified to work reasonably properly before purchase, for $90. No probes or manuals, but the traces and calibration outputs were all solid.
Assuming I don't have any problems returning the 465, looks like I finally have myself enough equipment to debug that $10 op-amp buffer I've been trying to build
Assuming I don't have any problems returning the 465, looks like I finally have myself enough equipment to debug that $10 op-amp buffer I've been trying to build
Ah yes, HF roll-off, a well-known problem whereby the signal falls off the end of the horizontal deflection ramp.
Sansbury: You are still murdering your tube. There shouldn't be any penumbra around your trace. The general rule with 'scopes is that if you can see the trace it's a tad too bright. (Lower brightness significantly helps focus.)
PS Don't take the HF roll-off comment seriously; I haven't a clue what would cause that very strange effect.
Sansbury: You are still murdering your tube. There shouldn't be any penumbra around your trace. The general rule with 'scopes is that if you can see the trace it's a tad too bright. (Lower brightness significantly helps focus.)
PS Don't take the HF roll-off comment seriously; I haven't a clue what would cause that very strange effect.
sansbury - an Iwatsu is supposed to be a pretty good scope. When deciding on my first scope I checked out an Iwatsu at a place in Seattle and was impressed with the quality. The salesman (to be taken with a grain of salt of course) mentioned they were very big in Japan and were the Tektronix equivalent. Just operating the controls verified if was high quality.
On my bench David and Goliath. Both are excellent scopes, but I have a little preference, despite the SIZE, for the 556 which can display 2 signals out of frequency or phase. You can even display XY on one channel and everything on the other AT THE SAME TIME !
Also excellent to heat up the garage in winter.....
Also excellent to heat up the garage in winter.....
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You are absolutely right, but I had the chance to find 2 556's ( vandalized , no tubes and missing parts !!! ) from which I rebuilt one. So I have some spares on hand including a second CRT. These scopes are fun to work with and easy to repair if no essential part broken ( i.e delay line or delay trigger...), they also are very cheap on the second or third hand market , user's manuals can be downloaded free of charge on BAMA and I encourage everyone to put these pieces of electronic art back to service.
Here a pic of the original scope shape.
Here a pic of the original scope shape.
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I love the old Tek scopes and use a 545B for just about everything. IMO, the 1A7A high gain diff plug-in is an essential tool when looking for ground problems, or anything else that's tiny and under a MHz. There is also a diode recovery time plug-in that's useful if you get a lot of surplus house number diodes. I have a couple of the spectrum analyzer plug-ins, and the audio unit is basically useless. You have to run it really slow to get any resolution and the scope doesn't have persistence. I think you are also stuck with a linear sweep. They were expensive for a while, but prices have fallen. Pretty much useless. The RF units are better, but are also complicated and hard to keep properly tuned up. They all tend to be unreliable, with dirty switches (sealed) and fussy calibration. For audio, you're way better off with a cheap or better sound card. I also have an HP selective voltmeter that's identical to their LF spectrum analyzer, but without the CRT. That's much more useful if you connect it to a chart recorder rather than a scope, but still way less useful than a sound card for SA applications.
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