This article discusses repair and calibration of the Hickok 6000 tube tester. Models 6000A and 6005 are the same with only minor feature differences that are not relevant to tube test calibration, therefore the discussion is applicable to those models as well. Serious electrical voltages are present, repairs should only be attempted by a qualified technician. Copyrighted by Bob Putnak, all rights reserved.

Introduction

Hickok 6000

Hickok 6000A

Hickok 6000 series is a compact mutual conductance tube tester. Most Hickok tube testers fall in two categories: those that use a 5 vac signal voltage and those that use a 2.5 vac signal voltage. Otherwise, most Hickok’s are remarkably alike (except for the really expensive models such as 539C or 752…). The 6000 series in the the 2.5 vac signal voltage group. The compact size of the 6000 is a welcome asset to any technician’s workbench because space is always at a premium. The 6000 series also has a replaceable socket panel.  One panel has an older compliment of sockets (4-pin through 9-pin-miniature sockets); the other panel has a newer socket compliment (compactron & novar sockets instead of the antique sockets).  This system allowed easy replacement of worn out sockets — the customer simply purchased a new panel from Hickok.

The setup chart configuration for the Shunt control gives “Good-Bad” readings, which were previously called the “English” readings in older Hickok testers.  In fact, the Shunt control was named “English” on older models.  The chart also provides a micromhos score for tubes that have transconductance (ie – not rectifiers, not diodes, not thyratrons…), and the Shunt control must be repositioned to the red dot on the Shunt control that is appropriate for that micromhos reading.  For example, if the chart says “2000″ and you had some reason to benefit from knowing the micromhos score (which is seldom the situation), you would ignore the chart’s shunt number and instead set the shunt control to the red dot near “73″ which is the 3000 micromhos range.  For most testing needs of a technician, the good/bad scale is convenient and appropriate.

Hickok 6000 paperwork package - $9.99 free ship USA

Need paperwork for your Hickok 6000? I offer a remastered paperwork package for Hickok 6000 — manual, schematic, remastered factory calibration document, and obsolete tube chart data supplement.  $9.99 free ship USA.


Vintage is approx 1957. The 6000 sold for $182 in 1958. Dimensions: 17 x 12 x 8 (inches) and weight 16-lbs. Model 6005 is the same tube tester but integrates multimeter functions. Model 6000A has basic transistor testing capability, which I doubt that anyone uses today. Most (not all) of the 6000A that I have seen have the newer socket panel with compactron and novar sockets. Which socket panel that is best for you will depend mostly on what types of tubes you test.

As a sidenote, this socket panel makes it very difficult to install socket-savers if you still want to close the case lid.  It can be done, but it requires a lot of work and creative thinking.  See my article HERE.

Repair and Calibration

A thorough explanation of the Hickok test method, calibration voltages, and the equipment that was used to make those voltage measurements is in a United States military document TM 11-6625-274-35 for military TV-7 series of tube testers.  This information is applicable to most Hickok tube testers (not all), with the caveat that some models use 2.5 vac signal voltage instead of 5.0 vac.  It explains the voltages for the plate, screen, grid, signal and the method used to obtain those measurements. A factory calibration document for the 6000 series also exists (and has one typo mistake) and closely follows the voltages in the military TM document.

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This article discusses repair and calibration of the B&K 600 / 606  tube testers.  Both models can share the same tube setup data book, and therefore both models are functionally equivalent.    Model 606 will be example shown in this article.  Electrical voltages are present, repairs should only be attempted by a qualified technician. Copyrighted 2010 TubeSound, all rights reserved.

Cosmetically, these models look like a little brother to their larger siblings — B&K 700 and B&K 707. Model 600 shares the same color scheme with Model 700, and model 606 shares the same color scheme as model 707. The wood case construction is similar also.

Electrically, models 600 and 606 are very similar (though not identical) to the “Switch” section (bottom panel) of the 700 / 707, employing the same grid leakage test and very similar tests for Emission Quality and Shorts.

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This article discusses repair and my calibration procedure of the Precision model 10-12  tube tester.   Serious electrical voltages are present, repairs should only be attempted by a qualified technician. Copyrighted by Bob Putnak, all rights reserved.

Introduction

6 Paco 10-series tube testers from my collection

The Precision Apparatus Company (commonly known as PACO) manufactured some very high quality test equipment.  Among their offerings are the “10-series” of tube testers, such as model 10-12, 10-15, 10-40, 10-54.  The tube test method is the same in all, and the test data is interchangeable.

I have been collecting since 1990, and in my experience model 10-12 was the most popular unit.  I have found many 10-12 over the past 19 years, and serviced many more.    I have only found one different model for my own collection, a model 10-40 that you see in the photo.

Precision Apparatus 10-12 tube tester with custom TubeSound plate current meter upgrade

It is easy to see why model 10-12 was most popular.  Four adjectives come to mind: Attractive, durable, consistent, quality.  Attractive — it has a beautiful furniture-grade hardwood case.  Durable — the entire unit is built-like-a-tank.  Consistent — I have always found these units to produce repeatable test results, year-after-year.  Quality — consistent test results from the “Electronamic” test method add up to a quality piece of test equipment.



Paco A-15 socket adapter

Paco G-140 Socket Adapter

The 10-series is also popular today because it will test a very large variety of tubes.  Model 10-12 has built-in sockets for antique tubes 4-pin, 5-pin, 6-pin, 7-pin large, and acorn.  It also has sockets for octal, loctal, 7-pin miniature, and 9-pin miniature.  Socket adapters (models A-15 and G-140) were later available, which adds the ability to test 10-pin miniature, nuvistor (5 & 7 pin), novar, and compactron tubes.  Therefore, if you have the socket adapter panel, you can effectively cover the entire range of tubes from antique 4-pin through modern 12-pin compactron.

The tester also has a NOISE JACK for connecting a set of headphones to audibly evaluate “tube noise.”

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This article discusses repair and calibration of the Signal Corp I-177  tube tester.   Serious electrical voltages are present, repairs should only be attempted by a qualified technician. Copyrighted by Bob Putnak, all rights reserved.

Introduction

Signal Corp I-177 tube tester

Model I-177 is a very old US Military dynamic mutual conductance tube tester that was used during World War II years.  The War Department Technical Manual is dated August 1944, and the tester calibrated in this article is dated April 1945. The unit is extremely well-built.  Due to its age and high signal voltage, the tester is only suited to test the “antique tubes” and military tubes of its era, and does not even have a 9-pin miniature socket. Although a socket adapter panel does exist to accommodate testing “newer” tubes, the tester is not suited for that task and can easily damage small signal tubes.  That said, the I-177 does an excellent job of testing the tubes of its era.


Repair

The fundamentals for starting the I-177 project: all knobs and the meter itself are indexed at zero, check all resistors and potentiometers for accuracy and replace where necessary , replace the 0.1 mfd capacitor, clean all sockets/switches/leaf-switches/pots/rheostat with Deoxit to the extent possible. I would specifically note that the I-177 has 7 carbon resistors.  Expect that most (if not all) of these carbon resistors will have increased in resistance and will need replaced.  The remaining resistors are either wirewound or precision types, and while they should be tested, it is unlikely that any would be defective.  Inspect all wiring (AC power cord, and also each wire connection at every tube socket pin).  Remove both bulbs (#81 fuse bulb and neon shorts lamp), clean bulb connections and sockets, reinstall.  The #81 fuse bulb must be only a #81 bulb (no substitutes).

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BK 607 tube tester

B&K 607 case

This article discusses the solid-state B&K 607 / 667  tube testers.  Both models use the same tube setup data book, and therefore both models are functionally equivalent.    Model 607 will be example shown in this article.  Electrical voltages are present, repairs should only be attempted by a qualified technician. Copyrighted, all rights reserved.

This series was B&K’s clone of the Sencore Mighty Mite TC162.  While the circuits are not 100% identical, they are close enough to be considered functionally identical.  The B&K 607 weighs slightly less than 6-lbs (without setup book or manual), and size dimensions are: 34 cm L x 24.5 cm W x 11 cm D.  The case folds open and easily accommodates a full size 8.5 x 11 inch setup chart and service manual as shown in the photo above.

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This article will discuss Mercury tube testers. The Mercury Electronics Corporation of Mineola NY produced a number of tube testers in the 1960s.  All models are small, portable, and lightweight.  Popular models include 990, 1000 / 2000, 1100, 1100A, 1100C, 1101.  Models and comments will be added as I find time.   Electrical voltages are present; repairs should only be attempted by a qualified technician.

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This article will discuss repair and calibration of the NRI Professional model 70 tube tester. High voltages are present, repairs should only be attempted by a qualified technician. Copyrighted, all rights reserved.

NRI 70 beautiful hardwood case

Introduction

Built by Precision Apparatus Co for NRI, the high-quality craftsmanship of the NRI Professional model 70 tube tester is readily apparent. It has a beautiful hardwood case (appears to be oak or birch) with finger-joint construction. Eight rubber feet protect your desktop in both the working position and the standup position. Internally, the tester uses a large beefy transformer and quality Pace (Precision Apparatus) meter movement. The tester has very small size, measuring only 10.75 x 10.75 x 6.25 inches (27cm x 27cm x 16cm) and weighs a hefty 10.4 lbs (4.7 kg). Most of the weight is due to the large transformer and hardwood case.

The NRI 70 has eight built-in sockets consisting of 4-pin, 5-pin, 6-pin, 7-pin large, 7-pin miniature, octal, loctal, and 9-pin miniature. All sockets use standard wiring (1-to-1, 2-to-2, etc.), and the control lever numbers correspond to their RTMA pin numbers (Lever 1 controls socket pin 1, Lever 2 control socket pin 2, etc.) (more…)

I recently found a February 1940 Jackson tube tester modernization bulletin. This bulletin explains the modernization options available for Jackson tube tester models 627, 627-C, 630, 633, 634, 634-C, 634-D, 635, 637, 680. It also includes the wiring diagram to install a Loctal socket into models 627, 630, 633, 635, 680.

Very interesting bulletin for anyone collecting or repairing vintage Jackson tube testers. I have scanned this 4-page document into a PDF for your benefit.

[ Download the Jackson 1940 Modernization Bulletin PDF ]

To summarize the bulletin:

• Models 634 and 637 sold in 1940 were already modernized at the factory
• Models 634 and 637 sold in their first year (1939) can be easily modernized by the owner (see my article on Jackson 634 for modernization data to install 9-pin miniature socket into these models).
• Models 627, 630, 633, 635, and 680 could be sent back to the Jackson factory and modernized for $5.00 (model 633) or $6.50 (models 627, 630, and 635, which dated from 1938), or $12.50 (model 680). All five of these models had to modernized at the factory because they required installation of a supplementary high-voltage filament transformer, among other parts.
• Models 427-A, 435-A, 535, and 580 were too obsolete to be modernized because “no provision for the high voltage filament types can be made. Miniature types cannot be tested.” Jackson noted that these models were “as much as five years old”, which dates them between 1935 and 1940. Jackson recommended upgrading to the new 1940 models of 634 and 637.

If you are only interested in the Loctal socket modernization wiring diagram, see the accompanying thumbnail photo (click photo to enlarge).

Loctal socket modernization

This article discusses repair and calibration of the older tube-based Sencore Mighty Mite tube testers that use the 12AU7A tube inside, such as model TC130, TC136, and TC142. I will also discuss the most common problem that causes “faulty” Grid Leakage detection. High voltages are present, repairs should only be attempted by a qualified technician. Copyrighted, all rights reserved.

TC130 Mighty Mite

TC130 Mighty Mite case

Introduction

Sencore Mighty Mite testers employ a Cathode Emission test circuit, with short detection and industry-best 100-Megohm leakage detection. The leakage detection circuitry is really the reason that every technician should own a Mighty Mite as part of his/her tube testing arsenal.

All Mighty Mites are designed to test newer tubes. You will not find any antique sockets (such as 4-pin, 5-pin, 6-pin, 8-pin large, etc.) Socket configuration consists of Octal, 7-pin miniature, 9-pin miniature, Nuvistor, novar, Loctal, and Compactron.

Each model has a roman numeral designation: TC130 = Mighty Mite III. TC136 = Mighty Mite IV. TC142 = Mighty Mite V. There are no practical differences among them.

The older Sencore Mighty Mite tube testers have tube circuitry inside, whereas newer Mighty Mites (such as TC154 and TC162) are transistorized. Otherwise, their functionality is comparable. Some units have a CRT picture tube wire harness with socket attached. This harness is very bulky, so common sense would suggest to remove it. It serves no practical purpose and only clutters up the case. Some models have a few pin straighteners on the front panel.

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This article will discuss repair and calibration of the Jackson 561 tube tester. High voltages are present, repairs should only be attempted by a qualified technician. Copyrighted, all rights reserved.

Introduction

The Jackson 561 appears to be a rare (uncommon) model. Very little documentation exists, and I have seen only a small number of them for sale.

The model 561 is a combination of the Jackson 634 and the 648. Photo below shows Jackson 561 (right); Jackson 648A (left).

Comparison: Jackson 648A vs 561

If the 634 and 648 mated, the 561 would be its offspring. It shares the following characteristics from the 648: (a) the same meter, (b) variable leakage control, (c) color scheme, and (d) case design. From the 634, it shares (a) the same test method (which Jackson calls “Dynamic Output”), (b) Shorts Test control, (c) lack of a Noise test, and (d) function control layout. In fact, the 634 tube setup chart can be used (with slight modification) with the 561, as explained later.

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