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Old 01-30-2017, 02:28 AM
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Simpson O-Scope & Signal Generator



Behold, the Simpson signal generator 317 and the Handiscope 466.

Years ago, my grandfather gave me these, he worked for Simpson, but these apparently belonged to a coworker. Neither works. And I was young and stupid and plugged the scope straight into the outlet and (I think) it exploded a small resistor. It was some years ago, but I recall opening the case and finding burnt plastic bits that looked like the remains of a resistor. But the kicker is - I have no idea where it was. A careful examination has left me clueless. There doesn't seem to be any leads floating in the air with no resistor between them.

Anyway, I'll be ordering a set of new capacitors, but in the mean time I was wondering if anyone here owns either of these, or better yet, if you have a manual for one?

Nobody has a manual for the generator - which is ok, I don't think I need it. But the scope seems like it's been worked on and modified a bit, and I'd like to know for sure whether I'm missing a resistor now. This dump and this dump offer manuals for the scope. I might just gamble on one of them.

Oscillocope 1
Oscillocope 2
Generator 1
Generator 2
Generator 12AU7 <- This tube is popped. I have a spare.
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Old 01-30-2017, 10:24 AM
dieseljeep dieseljeep is offline
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I had the larger model of the scope. I just bought it for parts, as the seller said the power transformer was shot, which it was.
I was surprised to see them using a 5Y3 instead of a 1V2, that most tube scopes used.
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Old 01-30-2017, 01:12 PM
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Quote:
Originally Posted by dieseljeep View Post
I had the larger model of the scope. I just bought it for parts, as the seller said the power transformer was shot, which it was.
I was surprised to see them using a 5Y3 instead of a 1V2, that most tube scopes used.
When I was in high school, I had an old Eico 425 that also used a 5Y3 as a hv rectifier... tube layout was very similar except it use octal tubes like 6SN7, 6J5 instead of the smaller 7 & 9 pin tubes in this Simpson 'scope. Extremely basic 'scope, using a 5BP1 CRT.

jr
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Old 01-30-2017, 06:28 PM
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Cool stuff! Super clean & it looks like they (Simpson) shared a similar enclosure style as Heathkit of that era. I wonder if they were available in kit form as a whole lot of stuff was back then. Some manufacturers offered either kit or factory built.

I can't think of what would have smoked out in that scope just by plugging it in that wouldn't leave some sort of evidence. It will be interesting to find out what that was. Let us know...
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Old 02-05-2017, 07:32 PM
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So I was at my grandpa's house today, shovelling a van-load of junk out of his garage. He had SO MUCH useless paperwork EVERYWHERE, that it didn't surprise me that he had file folders in his garage desk. What did surprise me was that as I poked through them, I saw an orange Simpson manual. Turns out, I stumbled upon the mother lode of Simpson manuals, original design and schematic drawings, and a whole bunch of other neat stuff. A lot of which directly links him to the design of several Simpson products. Pretty neat, eh?

But more importantly, I found these:



A tad surprising, since he said this pair belonged to his colleague and not him. But hey, I'm not complaining! In a couple days, I'm gonna order a bunch of caps for these and other projects, and get these going.

Oh! And question, guys: the scope has 9 capacitors that are 0.5uf 400/200v. Would it be ok to replace them with 0.47uf orange dips? 0.5uf are expensive
EDIT: Never mind, the manual calls for +/- 20% caps. With math, a +/-10% 0.47uf will still be within tolerance.


Quote:
Originally Posted by Tubejunke View Post
I can't think of what would have smoked out in that scope just by plugging it in that wouldn't leave some sort of evidence. It will be interesting to find out what that was. Let us know...
I looked over the schematic - now that I have it - and it sure looks like a resistor is completely missing across 2 big caps. And if I recall correctly, that area is the place I suspected. I'll take pics later, but I really just can't tell that anything was there. It must've blown the leads off of the joints. Maybe once I desolder them, I'll know. Also, looking over the caps and whatnot, I noticed a few things being awry. The can cap was replaced, the replacement missing a segment, which was replaced with a dry electrolytic that's half the uf it's supposed to be. There's an extra resistor, missing capacitor, and this rig has an unoccupied tube socket on the side that's been cut off from everything, and isn't in the schematic, and doesn't appear in the photo. But the place the socket goes sure looks like it was stamped out, not drilled. In-house experimental rig, I'd say.

Quote:
Originally Posted by dieseljeep View Post
I had the larger model of the scope. I just bought it for parts, as the seller said the power transformer was shot, which it was.
I was surprised to see them using a 5Y3 instead of a 1V2, that most tube scopes used.
There was a bigger Simpson scope? The only one I know of was the Genescope.

Quote:
Originally Posted by jr_tech View Post
When I was in high school, I had an old Eico 425 that also used a 5Y3 as a hv rectifier... tube layout was very similar except it use octal tubes like 6SN7, 6J5 instead of the smaller 7 & 9 pin tubes in this Simpson 'scope. Extremely basic 'scope, using a 5BP1 CRT.

jr
This one seems a bit simple as well. Probably a good thing, given I'm gonna be working on it. O_o

Last edited by MadMan; 02-06-2017 at 11:27 PM.
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Old 02-06-2017, 09:11 AM
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You should probably scan the manuals and submit them to a freebie manuals site - I try to do that with any/all odd manuals. The BAMA site along with eService and Electrotanya have helped me greatly, so I try to reciprocate.
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Old 02-20-2017, 02:16 AM
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Quote:
Originally Posted by Findm-Keepm View Post
You should probably scan the manuals and submit them to a freebie manuals site - I try to do that with any/all odd manuals. The BAMA site along with eService and Electrotanya have helped me greatly, so I try to reciprocate.
Working on it!



So, ok. I recapped both thingies. The signal generator, I haven't really tested it, but it turns on and doesn't catch on fire, so I consider that a win! The scope, on the other hand, had a whole lot more caps to replace, I finally got it done and went to turn it on. It started sparking at the crt base, a small fizzling spark like you'd get from a cracked solder joint. The base is broken (it was like that) and I had resoldered the pins years ago (they were all loose). I figured I must've done a shit job, so I redid it, twice, but I just couldn't get it to stop sparking there. Because the base is broken, and I don't feel like repairing it until I know all is working, I didn't want to totally unsolder it and redo it completely. So, I just so happen to have a nos crt to use. The scope has a 5UP1, but my new one is 5DEP1. From the info sheets, I can't see anything majorly different, but maybe you know something I don't?

Anyway, I tried the new crt, and when I turned it on, it immediately started sparking violently from the V4 socket (5Y3GT). I didn't risk leaving it on to pinpoint the location. I went through and retested all the tubes, checking especially for shorts, but all was ship-shape.

->Schematic<-

Coincidentally, that resistor I suspected missing is directly off of V4. It's R19, and I did indeed confirm it was there once upon a time. Unsoldering the capacitors there revealed two tiny sections of resistor leads. I have replaced it.

Before:


After:


It's also worth noting that it's pretty clear this scope was either an in-house experimental unit, or grandad and/or his coworker (the previous owner) did some hot-rodding.

Oddity notes:
C3A (near V1) was 50uf. It's now 100uf again.
C6 (near V2) is missing, still.
V2 pin 2 has a resistor to ground, still.

I don't think any of those things would cause it to spark violently at V4. As I turned it off within seconds, it didn't burn anything, so no evidence. The kicker is: the tiny little bitty sparking from the crt base was nowhere near the very loud snapping, obviously-high-voltage arcing from the bottom of V4. Also, I have not touched any of pins on the V4 tube socket. Unless the really bad sparking is simply because I tried the wrong CRT?



I didn't break it! Sadly, it's held to the chassis by a hose clamp, someone probably overtightened it. I was going to remake this with epoxy glue. Pretty sure it'll turn out fine, been practicing on other things. The leads are not touching each other, and I checked to make sure the base was properly aligned to the leads (by following the ones to the filament [also I had marked the No. 1 pin on the glass with marker]).

Last edited by MadMan; 02-20-2017 at 02:49 AM.
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  #8  
Old 02-21-2017, 09:47 PM
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Update: good news, I found the point of arcing. One of those little terminal strips had a carbonized section, and presumably that area handles HV for the CRT. I yanked the terminals off of it and no more arcing. Using the 5DEP1, I can get a line! It is a nos tube, but still, the display is nice and bright even in a lit room on the lowest brightness setting. I tried hooking up the signal generator to the scope, but unfortunately I couldn't get anything out of it. So one or the other is having a problem. I'll have to bring home my good O-scope and see if it picks up anything from the generator.

Sadly, I can't get the original CRT to stop arcing at the base. I'm gonna desolder it and remove it completely. Hopefully that's not carbonized too. O_o I can repair the breakage, but not much I can do if it's been carbonized... which come to think of it, aren't those bakelite? Isn't bakelite made from coal tar? Wouldn't that make it like 90% carbon anyway? Anyhow, if needed, can a replacement base be found?
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Old 02-22-2017, 10:35 PM
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Update again: Good news! I got the scope working. At least I think so. It's very responsive now and will pick up hum from me, or touching the leads to other things. Turned out to be a simple case of crusty tube sockets. I still need to get one of those terminal strips.

Bad news: the signal gen seems to be not working at all. I thought it was making a very low amplitude wave on the RF side, because I could see it on the scope and adjusting the amplitude knob on the gen affected it accordingly. That is, until I realized that the wave continued even after the generator was turned off lol. I guess the knob was acting as a sort of variable hum antenna. Shame, I'd thought the generator would be just peachy, it hadn't been modified and on fire like the scope had been.

I hate to be putting time on a NOS crt, but I have little choice at the moment. I'm keeping the brightness all the way down and the focus all the way blurry, even though, yeah, it's not like it's going to burn in over the course of 20 minutes or so. But still.


Last edited by MadMan; 02-22-2017 at 10:40 PM.
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Old 02-24-2017, 01:08 AM
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Apparently I forgot to attach the main power wire on the signal generator. O_o

So it works just fine now.
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Old 03-02-2017, 04:03 PM
wkand wkand is offline
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Those are very cool pieces!!!
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