Beauty of old electrical and measuring things, etc.

[Baluncore]

When I first acquired this radio I had to clean up the points in the vibrator. Those points are made of some of the hardest metal I have ever come across.

Iridium has been used for spark plugs and vibrator contacts because of it's high resistance to spark erosion. Platinum-Iridium 50/50 alloy is very much harder than Pt alone.

 

[dlgoff]

Horizontal gain is certainly not something you see on many scopes.

Thanks for posting your pictures. Here's my old Heathkit oscilloscope which has horizontal gain control.

 

[dlgoff]

I am missing knobs, but I can make those.

This old beauty is waiting for a restore.

It was missing a knob and I found one at http://www.oldradioparts.com/.
Here's their knob page where you may be able to find the right ones for your radio: http://www.oldradioparts.com/knobs.htm

Edit: BTW I love your radio's dial face. It's in really good shape. Who manufactured your radio?

 

[dlgoff]

... I doubt I will be attempting to measure 6 KV with it.

You never know. I've been measuring 4 kV lately doing Aluminum deposition on glass.

 

[dlgoff]

Iridium has been used for spark plugs and vibrator contacts because of it's high resistance to spark erosion. Platinum-Iridium 50/50 alloy is very much harder than Pt alone.

Wow. Never knew that. From http://www.rsc.org/periodic-table/element/77/iridium

Iridium is one of the rarest elements on Earth. ...
A very thin layer of iridium exists in the Earth’s crust. It is thought that this was caused by a large meteor or asteroid hitting the Earth.

 

[jim hardy]

I don't have the probes with proper banana plug.

https://www.digikey.com/en/product-highlight/p/pomona-electronics/1825-series-banana-plugs

 

[Averagesupernova]

Edit: BTW I love your radio's dial face. It's in really good shape. Who manufactured your radio?

Admiral.

 

[Nidum]

Anyone remember these ?

http://www.richardsradios.co.uk/avo8.html

 

[gmax137]

The owner caught me looking at this on his desk and made me take it away with me.

 

[dlgoff]

The owner caught me looking at this on his desk and made me take it away with me.

View attachment 214631

How cool is that? Lucky gmax.

 

[Bystander]

made me take it away

"Made?" Really had to twist your arm, didn't he/she?

 

[gmax137]

"Made?"

Yeah, we are consolidating office space here and everyone is having to pick & choose what to keep and what to toss. Luckily for me I have plenty of space at home for such things! And, I might have just walked past this old meter had I not been reading this thread. So thanks !

 

[jim hardy]

Are these two buttons at the bottom "Press to read" ?

That could be handy if like me, you get involved in troubleshooting and as often as not forget to change the range switch before touching the probe .
A 'Common Sense' feature.

 

[gmax137]

The left one is "Press for DC" and the right is "Press for AC." I am a novice at things electrical so I don't know how these buttons would be used. I did find a schematic on line but I have not deciphered it yet.

 

[dlgoff]

@gmax137 If you want to "clean it up", I've used Black Magic Pro Shine to make that old Bakelite look like new. It's really made for car's interior and exterior vinyl, leather and rubber surfaces.

 

[gmax137]

If you want to "clean it up", I've used Black Magic Pro Shine to make that old Bakelite look like new.

Thanks for the tip. I used a similar product with pretty good results. Here's after just ten minutes effort:

My previous experience is with a small radio-shack VOM. So I was curious, why is this so big and heavy? I opened it up to see what's inside. Wow. These must have been pricey when new.

The batteries are kind of interesting too. There are three, at 4.5 volts each. I shouldn't need them for the voltage and current measuring functions, right? Are they just for the resistance measuring?

 

[Baluncore]

I opened it up to see what's inside.

Regarding the small "cotton reels" mounted on the brass bolts, are those the precision range resistors, maybe wound with manganin wire? Do any have resistance values written on them? How many digits?

 

[dlgoff]

Thanks for the tip. I used a similar product with pretty good results.

Wow. Really looks even better now. Thanks for sharing.

I shouldn't need them for the voltage and current measuring functions, right?

Right.

These must have been pricey when new.

Part of the reason can be seen in the hand cable lacing done to bundle those cloth insulated wires.

 

[Bystander]

the hand cable lacing

Takes me back.

 

[gmax137]

Regarding the small "cotton reels" mounted on the brass bolts, are those the precision range resistors, maybe wound with manganin wire? Do any have resistance values written on them? How many digits?

Here's a closer look

They have numbers that look painted on in baby-blue. This one says "2500" and the adjacent on looks like "1500." But the paint is flaked off and it's hard to be sure. Sorry for the crappy photo.

 

[jim hardy]

I believe that's just what they are.

are those the precision range resistors, maybe wound with manganin wire?

see also https://www.radiomuseum.org/r/weston_665.html

http://www.antiqueradioexchange.com/index.php?a=2&b=694

 

[dlgoff]

see also https://www.radiomuseum.org/r/weston_665.html

Interesting that the meter in the video doesn't have the batteries:

The batteries are kind of interesting too. There are three, at 4.5 volts each.

 

[sparkie]

I'm quite impressed by how you built the setup with knob and tube wiring. Truly vintage! I'll keep you in mind as I run across old work. I ran into an old house one time that was all knob and tube, Edison fuse box and it used 24V lighting controls by means of mechanical maintain two position 5/16" round pushbutton switches. Really cool stuff. I actually pulled out an old Edison fuse box about a month ago that was in pristine condition. Too bad I pitched it already.

 

[dlgoff]

I'm quite impressed by how you built the setup with knob and tube wiring. Truly vintage!

Thanks @sparkie. We need electricians on our forum. I see you went (or now going?) to KSU. Do you live here in Kansas?

 

[jim hardy]

Interesting that the meter in the video doesn't have the batteries:

Reckpn somebody took them out so they wouldn't leak and corrode ? I was surprised to see them still in gmax's meter. He must live someplace dry...

 

[dlgoff]

I was surprised to see them still in gmax's meter.

Me too. And they look in such good condition that they might still have some charge.

 

[sparkie]

Thanks @sparkie. We need electricians on our forum. I see you went (or now going?) to KSU. Do you live here in Kansas?

Why yes I am. And I'm currently going. Knowing your in Kansas I'll make sure to shoot you a PM if I demo out any old equipment you may find interesting, but there isn't a ton of old work around here. Back home we had a LOT of old houses we did upgrades on. It is the vast majority of our work.

 

[dlgoff]

Why yes I am. And I'm currently going. Knowing your in Kansas I'll make sure to shoot you a PM if I demo out any old equipment you may find interesting, but there isn't a ton of old work around here. Back home we had a LOT of old houses we did upgrades on. It is the vast majority of our work.

Awesome. I'm a KU grad. Rock Chalk Jayhawk.
PM me if there's anything I can help you with in your studies, etc. Nice to have another Kansan PF member. You, @Evo, and myself are the only ones that I know of.

Regards

 

[dlgoff]

Reckpn somebody took them out so they wouldn't leak and corrode ?

After you posted this, I looked for that 30Volt battery I took out of the Triplett 360-A but couldn't remember where I stored it. It still had a lot of charge when I removed it.
From https://www.physicsforums.com/threa...asuring-things-etc.755959/page-5#post-5122869

 

[Bystander]

Kansan

Oh? 'Nother one? Like me?