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. |
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National CRU-P This 2" National is identical to the Model CRU shown above, except that the front panel is laid out horizontally. |
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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. |
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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 1940’s as United Television Laboratories aimed at TV repair following the WWII boom. later in the 50’s they changed their name to United Electronics Laboratories, and by the early 60’s 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. |
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.
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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 3" 3AP1/906 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.
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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.
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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. |
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Blue trace of the P5 phosphor. |
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. |
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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.
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RCA TMV-122B
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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" CRTThis 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. |
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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.
April, 1932
ad from Radio Retailing
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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. |
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Jackson Model K 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.
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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.
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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.
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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. |
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. |
IBM Tube Tester
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Miscellaneous Testers
Meissner Analyst
A multipurpose tool for the service technician has the
following functions: Original cost $113.85,
catalog ad |
Supreme Model 581 Signal Generator |
Vision Research Laboratories TSW-50 Early Television sweep generator |
Philco Model 7008
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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 510X
A multi-purpose device. A mutual conductance tube tester, DC voltmeter, AC voltmeter, Ohmmeter, and capacitor tester. |