Vintage Test Equipment

 

On this page I will be displaying various types of vintage test equipment I have acquired over the years, some pieces will be common but interesting others not so common. Click on any picture to see a high definition picture of the piece. Hope you enjoy the tour.

 

 

OSCILLOSCOPES

 

National CRM

Uses a 1" 913 CRT for display. This line of National scopes were intended for use by radio operators, they were used to monitor modulation and have only minimal components as shown in schematic. Time base for horizontal sweep was derived from the AC power line at a 60 cycle rate or an from external signal. List price was $18.50 less tubes, see ad here.

National CRU

Uses a 2" 2AP1 CRT for display. As in the model CRM the unit has only two tubes, the CRT and a rectifier. List price was $32.50 less tubes.

 

National CRU-P

This 2" National is identical to the Model CRU shown above, except that the front panel is laid out horizontally.

 

National CRR (?)

Not really sure if it is a National piece or a copy. It has no ID plate or markings anywhere, other than the engraved knob labels on the panel. It uses a 2" 2AP1 CRT for display and a 6X5 rectifier rounds out the tube complement.

 

National CRO

The CRO is circa 1934-35, it uses the 3" 906 CRT and an 80. The set weighs in at about 11 lbs. and the list price without tubes was $29.50. As in the other National 'scopes this one was used mainly for checking modulation levels in HAM transmitters.

 

RCA Model 151 

Uses a 1" 913 CRT for display. This scope was introduced around 1936 at cost of $47.50, by 1938 the cost was 39.95. These prices included tubes, see ad here.

RCA Model 151-2

Uses a 2" 2AP1 for display. This model is identical to the model 151 except that a 2AP1 CRT was shoehorned into the box, the tube had to be installed at an upward angle to fit in the shallow cabinet.  This scope was introduced around 1938 at a cost of $49.95

 

Inside chassis view of the RCA 151 oscillograph.  Typical of most 1930's oscilloscopes, this uses a 885 as the horizontal sweep generator, 6C6's for the horizontal and vertical amplifiers and an 80 rectifier.

 

Deforest's Training Inc.

This scope was used as part of a training course. Possibly from the original DeVry Institute which was started in 1931 as the DeForest Training School, as the name on the unit doesn't quite match, I can't say for sure. No cabinet, click here for a side view.

UTL Model E

This scope was used as a training project for students enrolled in the United Television Laboratories School. The school started off in the 1940ís as United Television Laboratories aimed at TV repair following the WWII boom. later in the 50ís they changed their name to United Electronics Laboratories, and by the early 60ís became United Electronics Institute. By the 1980's they were gone. The cabinet is home made, it uses a 2" 2AP1 CRT, has vertical and horizontal amplifiers, and linear sweep generator.

 

 

Homemade

Uses a 1" 913 CRT, probably dates from the 30's. Direct connection to the deflection plates, probably used in a HAM shack as modulation monitor. Well constructed cabinet made up of 7 pieces all screwed together. Circuitry very similar to the National CRM above.

Homemade

This one uses a 2" 2AP1 CRT. It is very crudely built as can be seen in the photograph below. It is a true scope as it has a 884 tube to generate the linear sweep.

 

Inside view of the 2" homemade oscilloscope, wiring is very shoddy. Under the chassis connections are hanging in mid air. This set uses 6J7 for horizontal and vertical amplifiers, 6X5 for HV rectifier, 5Y3 for LV rectifier, and 884 as horizontal sweep generator.

 

 

Supreme Model 530

Uses a 2" DuMont 24-XH CRT for display. Typical of early Supreme equipment, this is housed in a dovetailed, quartersawn oak cabinet. Very primitive set, has only 2 tubes, besides the CRT. A 5T4 rectifier and a 6J7 vertical amplifier. Sweep is either external or internal 60cycle

Supreme Model 535

Uses a 2" 2AP1 CRT for display. Typical of early Supreme equipment, this is housed in a dovetailed, quartersawn oak cabinet. This updated model has vertical and horizontal amplifiers, and a real horizontal sweep generated by a 884 tube. Original cost was $49.95

 

Supreme Model 546

Uses a 3" 906 CRT for display. Typical of early Supreme equipment, this is housed in a dovetailed, quartersawn oak cabinet, brushed brass art-deco front panel and a highly nickel plated chassis shown below.  This early version dates from around 1938.

 

 

 

Clough-Brengle Model CRA

Uses a 3" 906 CRT. In 1935 this set cost $79.50, increasing to $84.50 in 1936.

Supreme Model 546-A

A later version of the Model 546 line of scopes, electrically it is identical to the earlier versions. This model has a metal cabinet and the chassis is painted wrinkle black. The 1941 price was $64.50

 

 

 

Supreme Model 560A

The Vedolyzer uses a 2" 2AP1 CRT for display. This device was called a "Complete Dynamic Analyzer", it consisted of a oscillograph, vacuum tube voltmeter, dynamic signal tracer, multimeter, and a wave meter all in one 35 lb. package.

Described in the 1941 catalog:

"SUPREME engineers proudly present the SUPREME VEDOLYZER as the zenith in DYNAMIC TESTERS--the instrument that will strike off the fettering bonds of "buggy" time-losing, loss-producing receiver servicing."

The price for this in 1941 was $129.50

 

 

 

Philco Model 7019

Uses a 2" 2AP1 CRT for display. Also known as the "Junior Scope", small and lightweight it sold for $66. This set is very similar to the Waterman scope. Click here to see ad.

RCA Model WO-57A

Uses a 3" 3MP1 CRT for display. This CRT is very short about the same as a 2AP1, this allows the 3" scope to be housed in a case not much deeper than the Model 151 shown above. This set is from the early 1950's. It is an updated version of the WO-55A produced in 1948.

 

 

 

 

Clough-Brengle Model 126

This set uses a 3" 906 CRT for display. This is very similar to the Model 126A shown below. This model was produced in late 1937, see packing list.

 

Clough-Brengle Model 105

Uses a 1" 913 CRT. In 1935 this set cost $48.50.

 

Inside view of the Clough-Brengle Model CRA oscillograph, the 906 CRT is an early version of the 3AP1 CRT without the internal aquadag coating allowing you to see the gun components and the rear of the screen.

 

Clough-Brengle Model 126A

This set uses a 3" 908 CRT for display. The 908 is the same as the 906 except it has a P5 phosphor. This is a blue trace with a very fast decay time used for photography applications.

Inside view of the scope. Unusual construction is used in this set, instead of the components installed on a standard chassis, the parts are attached directly to the cabinet. This set has been restored.

 

Blue trace of the P5 phosphor.

 

General Electric Model CRO-3A

Uses a 3" 3AP1 CRT. Circa late 40's early 50's

This is a 2-terminal (diode) curve tracer. I believe it was made in the model shop at Raytheon, as it came in a lot with other items from them. It uses a 3" 3KP1 CRT. Not really sure how it operates, it has two test fixtures one labeled "static" the other "dynamic". This is the only display I can get with a diode connected to the dynamic fixture.

 

RCA Model 155

Uses a 3" 3AP1 CRT, uses same internal components as the Model 151. This scope was introduced around 1938 at a cost of $63.95, included tubes.

DuMont Model 164

Uses a 3" 3AP1 CRT. The internal components have been coated with a sealer, typical of what you find in military gear that was to be used in areas of high humidity. A label dates that the coating was applied in August 1945.

 

DayRad 65

Uses a 3" 906 CRT. In addition to being a general purpose oscilloscope this unit contains a wobbulator, a motor driven sweep generator, to do sweep alignment of equipment.  

 

RCA TMV-122B

 

 

 

 

Inside view of the RCA TMV-122B oscillograph, the CRT is an early 3" 906 clear bulb.

 
 
 

Bendix Model 160

Has a built in sweep generator centered at 1Mhz, sweep width of +/- 15Khz. The center frequency can be shifted up or down by connecting a signal generator to the bottom terminal posts and tuning it to the desired center frequency.

Close up of the CRT mount showing the sweep graticle. For the operators manual click here.

 

 

9Z4P1 / K1207 - 9" CRT

This large CRT contains five independent electron gun assemblies, each gun has its four deflection plates brought out around the neck of the tube. I did find a mention of this tube used in a high speed display unit used by NASA for radio astronomy.

 

Close up of the 5 electron guns

The dual set of pins on base

 

Size comparison, the tube in front is a 3AP1

 


 

TUBE TESTERS

 

Weston Model 788

Also known as OQ-3 in the Military version. To test tubes, individual jumpers are connected between the tube socket panel and the tester panel

Weston Model OD-5

 This is the military version of the Weston 686. It is  rack mounted and huge 3' high and 20" wide, weighing in at about 75 lbs. Connect the tube elements to the tester is by short jumpers between the panels and then setting the voltage requirements for each element. Presently this unit is not functional, the weak point in the tester is the large high resistance, high power rheostats that are used to control the plate, suppressor, & screen voltages fail, and I haven't been able to find suitable replacements.

 

Weston Model 672

One of the counter top testers of the early 30's. The large 9" diameter meter allowed the customer to see how bad his radio tubes were and he needed to purchase Silvertone tubes for his radio.

 

Jewell 538

This early 30's counter top tester sports an 8" diameter meter for test results. The other meters are used to adjust line voltage and set operating point for the tube under test. It tests about 22 types of tubes, each displayed on a scale of the large meter, for GOOD, BAD, and MAYBE.  You first plug the tube into one of the sockets on the left side of the tester to check for shorts, if there is a short the white circle to the left of the meter lights up with the word "SHORT". If the tube has no shorts then you plug the tube into one of the sockets on the right side to check for quality.
After Weston purchased Jewell many of these "old style" testers were modernized to check  newer tubes.

April, 1932 ad from Radio Retailing
Tester in use at Radio Shop

 

 

Weston Model 555

This tester is designed for testing tubes at time of sale, it dates from 1931 and list price was $67.50, limited to 4 and 5 pin tubes. Apparently it is capable of testing Kellog type tubes with the filaments brought out on a top cap.

Triplett Model 1610

 "Robot" tube tester, not much to say other than a very interesting setup keyboard style.

 

Jackson

No other markings are on this small tester, the tube chart located on the "step" is so small you need a magnifying glass to read the tube settings. Test setup is done with jumpers.

 

 

Radio City Products Model 308

This tester probably dates from the early 40's, "DYNOPTIMUM" was more than likely a sales gimmick. The meter is in upside down, that's the way I got it. May have been turned so customers could see the tube results while the serviceman did the test.

 

 

 

Sterling Model R-402

A battery operated tester for early battery tubes like the 201 or 199.

Supreme Model 35

Original cost was $29.95

 

Sterling Model R-404

An early tester used to rejuvenate the filaments on tired tubes and test filament emission.  Rejuvenating the filament was used only on thoriated filament tubes.

 

 

Supreme Model 89 Deluxe

This one is housed in a portable case with lid. Also has the capability to test capacitors.

Supreme Model 89 Deluxe

This one housed in a slant front bench case. Original cost was $45.95

 

 

Stark Model 911

Basic emission tester. Nothing really special about this unit, I just liked the color combination with the bright red sockets, knobs and meter.

Triplett Model 1213

Another basic emission tester, small portable unit, circa late 1930's.

 

 

Philco Model 7053

CRT tester, this tester can test magnetic deflected CRT's such as 10BP4, as well as electrostatic deflected like the 7JP4. It is just a simple emission test with results shown on the neon bulb. The cables are stored in the pull down door.

Transvision Component Tester

I know virtually nothing about it. Apparently in addition to testing CRT's it will also test flyback transformers, and selenium rectifiers and rejuvenate cathode of the CRT.

 

 

Oak Ridge Products

CRT tester. Another test unit I know nothing about. Apparently it was connected in line with an active CRT and tested the CRT under operating conditions. It also included a 500v and 15KV voltmeter.

-ibmtube-

IBM Tube Tester


This is an unusual tube tester, circa 1948 from IBM, yep the computer people. The test setup chart that is with the unit has just 3 tubes listed for testing,  25L6, 6SK7, & 12SN7. The test setup consists of connecting the tube pins to the tester by the use of short jumpers, and then setting up each elements' parameters. It also contains a full VOM.

 


 

Miscellaneous Testers

 

Meissner Analyst

 

 

A multipurpose tool for the service technician has the following functions:
An audio amplifier with phone jack output
An AC voltmeter with range of 0.1 to 1000 volts
A DC voltmeter with a range of 0 to 500 volts
A frequency meter with
   Vacuum-tube voltmeter with a range of .05 to 50 volts
   Measuring frequency from 600KC to 15MC
A TRF tuner with phone jack output with
   Vacuum-tube voltmeter with range of 50 microvolts to 50 volts
   Measuring frequency from 100KC to 1700KC
A line-current ammeter

Original cost $113.85, catalog ad

For the operating manual in PDF format, click here.

 

Supreme Model 581

Signal Generator

 

Vision Research Laboratories TSW-50

Early Television sweep generator

 

Philco Model 7008

 

 

Hickok OS-10

RF generator and AC meter.

Jackson 650A

Capacitor tester. It has a test range of 10pf to 1000uf, up to 500 volts. Surprisingly it is very accurate, I  checked it against my Sencore Z-Meter and found the results virtually identical. The 1941 price for this set was $29.95.

-201R1K

United Systems Corp. 201R1K

What makes this "digital" voltmeter unusual is that the display is mechanical. I haven't been able to find any information with a cursory search through the internet. I would say it dates from the late 60's to early 70's, it contains about 7 transistors (click here for interior view) it is very noisy when measuring. (Click here to see it in operation).

 

Hickok Test Bench

This bench unit contains a Model 177X Signal Generator, a Model 510X Mutual Conductance Multi Tester, and a Model TS-50 Universal Test Speaker, two electrical outlets, a patch panel, lights built into the top overhang to light up the work bench.

 

Hickok Model 177X

 

 

 

Signal generator.

 

Hickok Model 510X

 

 

 

 

 

A multi-purpose device. A mutual conductance tube tester, DC voltmeter, AC voltmeter, Ohmmeter, and capacitor tester.

 

Hickok Model TS-50

 

 

Universal Test Speaker

 

 

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