Mid 50's "U-TEST-M" Drug Store Tube Tester Restoration

Back in the late 1950’s when I was 12 or 13, I started playing around with old TV sets to see how they worked and to see if I could repair them.  AT that time I didn’t understand much about electronic theory, and most of my tinkering consisted of making adjustments and testing and replacing tubes.  In the beginning I didn’t have a tube tester, so testing tubes meant a trip 3 blocks to Rosen’s Drug Store on the corner of Hampton Avenue and Santa Monica Blvd.  There in a front corner of the store next to the front windows, was a U-TEST-M self service tube tester; and that is where I did my tube testing.  It’s funny how certain images from your childhood stick with you.  I can picture that tube tester at Rosen’s Drug Store just as clear in my mind as if it was yesterday.

So as I started getting more seriously involved in my TV collecting and restoration hobby, I started thinking about that U-TEST-M tester that I used as a kid at the drug store down the street.  And then one day a fellow TV collector friend of mine in Chicago called me and said that there was a U-TEST-M tube tester on Craigslist in the Chicago area.  I contacted the seller and he sent me a photo of the unit.  I was in luck; it was the exact same model that was in Rosen’s Drug Store.  I told the seller I wanted it and drove to Chicago the next day to buy it and haul it home.

The seller told me that his father-in-law owned a Phillips 66 service station until the late 90’s, and when he closed the station this was one of the things that they saved from the trash.  Back in the 50’s, 60’s and 70’s it was common for do-it-yourselfers to try fixing their own TV sets by testing tubes where ever there was a self service tube tester.  These self service tube testers were commonly found in drug stores, hardware stores, service stations, and even some large grocery stores.   The cabinet contained a stock of new vacuum tubes that the store owner would sell to his customers.  The tube inventory was replaced by a route salesman who would stop buy periodically and replenish the stock and bill the store owner at wholesale for the price of the tubes that were needed to restock the inventory contained inside the tube tester cabinet.

Because this particular tube tester was in a service station, it was not in a nice dry, controlled temperature, environment.  As a result the cabinet was in very poor condition.  Much of the paint was scratched and chipped and the metal cabinet had a lot of rust. This is a photo of the condition that the U-TEST-M was in when I received it. 

Inside the cabinet I found several hundred old used vacuum tubes, which I eventually tested and the good ones were added to my inventory of spare vacuum tubes.  I also found some old U-TEST-M advertising literature, which you can see scans of here.  I took the originals to a copy store and had a bunch of reproduction color copies made to place in the literature holder on the side of the cabinet.  ON the back of one of the U-Test-M books that were in the cabinet, was the address of the company.  I discovered that the U-Test-M was located on the south side of Milwaukee where I have lived my entire life.  Evidently at some point in time the U-Test-M company was purchased by the John C.Sperry Company and was re-located to Lincoln, Nebraska.


Prior to starting the cabinet restoration I took several photos of the decal on the front of the cabinet.  The old decal was in horrible condition as can be seen in this photo.  I loaded the photo into my computer and used Microsoft Publisher to generate an exact duplicate art file of the original decal.  I outputted the  Publisher file as a .jpg and loaded it on a thumb drive and took it to Kinko’s.  I had Kinko’s make several “bumper sticker” type prints of the art work.  I had Kinko’s laminate a clear film over the new decals for durability. Here is the original art work .jpg that I created, and a photo of the finished decal affixed to the front of the restored cabinet.

I began the restoration by completely disassembling the entire cabinet.  The tube tester itself did not work and there were no schematics available to assist me in the repair of the tester.  After many hours of checking wiring and components, I located an open section of a very large tubular wire wound resistor that had about 10 taps on it.  I was able to determine the value of the section that was open by measuring each half of the open section with an ohm meter and then I bypassed the bad section with a wire wound resistor of the correct value.  That got the tube tester unit back into operation.

The vacuum formed plastic U-TEST-M sign was in very poor shape,  and it was very dirty with years of grime.  I used heavy soap and water and ammoniated window cleaner to clean the sign back to a respectable condition.   All of the sides of the sign were badly cracked and there were pieces missing. So I used white styrene sheet material which I get at the hobby shop, and made new sides for the sign and attached the new sides to what was remaining of the broken original sides.  Except for a small missing piece in the upper right corner which can be seen in this photo, I was able to pretty much salvage the sign, and it looks pretty nice when you light it up.  At some point in time somebody splattered black paint on the sign and so it has black freckles on it which I did not attempt to remove because I was afraid of causing more damage to the sign in the attempt.

AT this point I moved on to restoring the metal cabinet.  I started by sanding down all the cabinet components.  Then I sprayed the cabinet with a gray automotive primer.  The original color of the cabinet was the typical gray hammer tone that was typically used on electronic equipment of the era.  I ordered a quart of gray “Hammerite” hammer tone enamel online and when it arrived I sprayed all the cabinet pieces with two coats.  The cabinet door was basic fire engine red.  I bought two spray cans of gloss fire engine red enamel and gave the front cabinet door 3 coats on both sides. The base toe-kick pedestal was repainted with gloss black enamel to complete the job.   With the painting completed I re-assembled all of the cabinet components including the actual tube tester.  I re-installed the original tube chart which was in relatively good condition.  The cabinet door lock was missing.  I searched around on eBay and found just the right type of lock needed.  With the lock installed the cabinet restoration was complete. 

Here are a few of photos of the finished restoration, including close ups of the tube chart, and the tube tester.  I have been saving empty tube boxes and whenever I get a few I put them in the tube drawers for display purposes.