View Full Version : Philco 7020 3" portable scope


bandersen
11-11-2010, 08:17 PM
I recently picked up this little 3" Philco 7020 oscilloscope. The manual is dated 1952 and has "Television Home Study" on the cover. The manual covers basic scope theory then focuses on using it for TV servicing.

I don't have any real use for it, but I kinda like it and will attempt to restore it :)
Luckily, I also have the service manual. It's actually fairly complicated for such a compact scope.
http://farm2.static.flickr.com/1201/5167873375_04be1f072c_z.jpg http://farm5.static.flickr.com/4153/5168475334_9122e9e777_z.jpg

I'll scan both manuals shortly. I'd better hurry before they disintegrate :yikes:
http://farm5.static.flickr.com/4104/5168476060_84f6c706a4_z.jpg http://farm5.static.flickr.com/4125/5167873999_ff53b9b915_z.jpg

It's pretty tight inside!
http://farm2.static.flickr.com/1407/5167897671_5e64cecc5a_b.jpg

The 3RP1 is directly soldered in. Probably no room for a socket.
http://farm2.static.flickr.com/1387/5167897857_a347705bae_z.jpg

Lots of nasty old caps. New ones should arrive tomorrow.
http://farm5.static.flickr.com/4088/5167898063_73ea7279c4_z.jpg

jr_tech
11-11-2010, 09:35 PM
Some time ago, I had a similar looking 'scope branded "Waterman". IIRC the CRT did have a socket, perhaps a cheap "wafer" design, that might break easily.

Cool Find! :thmbsp:

jr

AUdubon5425
11-11-2010, 10:02 PM
I like it. I have an old DeForest scope of similar vintage I want to fix up one day.

bandersen
11-16-2010, 12:07 AM
Thanks. It's slowly coming along. The hardest part was getting the hardened rubber bezel of the CRT without breaking anything. I liberally applied some ArmorAll and let it soak in for a few hours. That softened it up just enough.

What I thought was dirt turns out to be phosphor loss :(
http://farm2.static.flickr.com/1178/5181146794_a8cb7d11e9_z.jpg

Then, I had to unmount every control to get the chassis out!
http://farm5.static.flickr.com/4133/5180548071_4dfbc7efe0_z.jpg

At last the fun can begin :)
I scanned the instruction manual and uploaded it here (http://www.bobandersen.com/images/scanned%20manuals/Philco/Philco%207020%20Instruction%20Manual.pdf)
http://farm2.static.flickr.com/1295/5180548255_9fa579e20c_b.jpg


Some time ago, I had a similar looking 'scope branded "Waterman". IIRC the CRT did have a socket, perhaps a cheap "wafer" design, that might break easily.

Cool Find! :thmbsp:

jr

Cool. Is it this one ? http://cgi.ebay.com/vintage-waterman-products-oscilloscope-/140476473677

Don Lindsly
11-16-2010, 10:35 AM
The Waterman in the link is a much simpler 2 inch scope, using 4 tubes total. The Philco version, built by Waterman, is designated the model 7019. They are virtually identical.

The 7020, 3 inch scope was renamed the S8200 in later versions. It uses eight tubes.

Sandy G
11-16-2010, 10:42 AM
I vaguely remember seeing in Fair Radio catalogs of years past a Navy scope- USM/OS-3- that looked a lot like this l'il guy...I think they made both Tooob & SS versions of it. I had a Waterman pocketscope, never could find probes for it, eventually gave it away.

mbear2k
11-16-2010, 12:46 PM
Cool scope. And interesting in that I was reading an Philco "Television Home Study" guide/pamphlet last night that references that exact scope throughout. If you want the guide to go with the scope, let me know.

Mark

radio63
11-16-2010, 07:12 PM
Wow, what a job to get it out of the case! Cool scope though. Looks like the silverfish were making a meal out of the manual!

Gilbert

jr_tech
11-16-2010, 07:42 PM
Cool. Is it this one ? http://cgi.ebay.com/vintage-waterman-products-oscilloscope-/140476473677

I'm not a 100% sure, but I think that it was a 3" Waterman rather than 2". A friend had a smaller Waterman or Philco that was really cute, and IIRC was blue rather than grey.

jr

bandersen
11-17-2010, 12:30 AM
Wow, what a job to get it out of the case! Cool scope though. Looks like the silverfish were making a meal out of the manual!

Gilbert

Ah-ha - so silverfish make holes like that in paper ? Didn't know that.

Cool scope. And interesting in that I was reading an Philco "Television Home Study" guide/pamphlet last night that references that exact scope throughout. If you want the guide to go with the scope, let me know.

Mark

I did get a home guide with this scope (bug holes and all). Does yours look like the pictures in my first post ?

I've scanned the whole guide here (http://www.bobandersen.com/images/scanned%20manuals/Philco/Philco%20Television%20Home%20Study%20using%207020% 20Scope.pdf).

mbear2k
11-17-2010, 09:04 AM
I did get a home guide with this scope (bug holes and all). Does yours look like the pictures in my first post ?


Mine is a Home Guide for troubleshooting TV issues - and references (and shows a small pic) your scope. I will scan and post!

bandersen
11-17-2010, 11:07 PM
That would be great - thanks!
I'm make slow, but steady progress. I've never seen so many bad resistors. Seems the lower the value, the further out of spec they are :scratch2:

I dug up a spare 3RP1A in case this CRT is bad or weak.
http://farm5.static.flickr.com/4130/5185960917_56f641d6ae_b.jpg