Great haul today!

Thread Starter

DerStrom8

Joined Feb 20, 2011
2,390
A 5Y3 is still a common enough tube. Better to keep it as is to avoid the B+ arriving before the other tubes are warmed up. Still...

You could replace it with silicon diodes if the peak voltage doesn't get too high for the capacitor during warm up, and you would have to add resistors to keep the B+ voltage from being too high continuously. (I've done it.) IIRC, that one needs about 80 ohms in series with each silicon diode. Just in case the day comes when you can't buy a 5Y3.;)
Yeah, I knew I could just make my own rectifier, but I figured if I can still get my hands on a tube, that'd be the best route.

Thanks guys! More on this when I get it reassembled with a new tube!

Matt
 

THE_RB

Joined Feb 11, 2008
5,438
Did you check the heater filament on the CRT?

It's also a good idea to inspect, clean and re-tension all the tube socket contacts. Look for heat discolouring of the metal contacts and corrosion. (That includes the neck socket on the CRT.)

And if you want to actually use it a lot of those paper caps may need replacing. :)
 

Thread Starter

DerStrom8

Joined Feb 20, 2011
2,390
Hey folks! Just a quick update on the scope--

I bought a new rectifier tube on ebay for $6. Finally got the chance to install it this afternoon. Switched the thing on, and voila! Had a trace!

I happened to have one of my audio signal generators lying around, so I hooked it up, but was a bit confused as to the connections. To be honest, this scope is a bit old for me, my first scope was a CRT one in the '80s. Never had to deal with vacuum tube ones. Below is another look at the front panel. There appears to be two inputs--a "horizontal input" and a "vertical input". I'm trying to display a basic sine wave, but it only displays what appears to be a rotating image (looks almost like a spinning Pringle). I'm wondering if I've got the connections wrong. I've only seen rotating images in X-Y mode before, so I must have something connected incorrectly. I have the signal connected to the vertical input +, and signal ground connected to the vertical input gnd. Any thoughts? Thanks guys!

IMG_5886.jpg
 

Thread Starter

DerStrom8

Joined Feb 20, 2011
2,390
Thanks The_RB. Tried that, but no such luck. I'm getting a straight, vertical line, it has some slight "wobble" but it's the same rotating image, just on a smaller scale.
 

killivolt

Joined Jan 10, 2010
835
Hey folks! Just a quick update on the scope--

I bought a new rectifier tube on ebay for $6. Finally got the chance to install it this afternoon. Switched the thing on, and voila! Had a trace!

I happened to have one of my audio signal generators lying around, so I hooked it up, but was a bit confused as to the connections. To be honest, this scope is a bit old for me, my first scope was a CRT one in the '80s. Never had to deal with vacuum tube ones. Below is another look at the front panel. There appears to be two inputs--a "horizontal input" and a "vertical input". I'm trying to display a basic sine wave, but it only displays what appears to be a rotating image (looks almost like a spinning Pringle). I'm wondering if I've got the connections wrong. I've only seen rotating images in X-Y mode before, so I must have something connected incorrectly. I have the signal connected to the vertical input +, and signal ground connected to the vertical input gnd. Any thoughts? Thanks guys!

View attachment 60319
You are now in the "Twilight Zone" :p

Good job, D8.

Good luck on the rest:)
 

killivolt

Joined Jan 10, 2010
835
Thanks The_RB. Tried that, but no such luck. I'm getting a straight, vertical line, it has some slight "wobble" but it's the same rotating image, just on a smaller scale.
With limited knowledge and maybe some weird sense. I would on tuners back in the day, especially old equipment.

Someone told me, on another site, going out on a limb to sound dumb here, but WD40 in the tuners to clean them up?

It works on Amp and Guitars, maybe Oscopes?

Edit: Cleaned up my spelling.
 

killivolt

Joined Jan 10, 2010
835
Yeah, I knew I could just make my own rectifier, but I figured if I can still get my hands on a tube, that'd be the best route.

Thanks guys! More on this when I get it reassembled with a new tube!

Matt
I always buy spares, if I can buy one why not 4.

I know I'm a waster, but waste not want not:p
 

Metalmann

Joined Dec 8, 2012
703
With limited knowledge and maybe some weird sense. I would on tuners back in the day, especially old equipment.

Someone told me, on another site, going out on a limb to sound dumb here, but WD40 in the tuners to clean them up?

It works on Amp and Guitars, maybe Oscopes?

Edit: Cleaned up my spelling.

Yes, Deoxit-D5 may be the best, but WD40 has really saved the day on many, many, Guitars and Amplifiers.
 

killivolt

Joined Jan 10, 2010
835
Yes, Deoxit-D5 may be the best, but WD40 has really saved the day on many, many, Guitars and Amplifiers.
Yeah, it's best to just pull them out and get them on the bench with towel. It's best to drench through the stem, into the pot, let set and re-apply. Then move the tuner back and forth rotating as you do it.

Repeat the process, a couple of times. Then stand the tuner on it's stem to let drain if need be, overnight. In the morning, rotate back and forth over and over.

It may or may not help the pot, but as far as I know it's safe, not like some electronic cleaners that will melt plastic.
 
Top