FOR SALE

Quality Test Instruments for Technicians or Hobbyists

*Free standard shipping for all test equipment and accessories on this page.

Offer good for continental USA only.

USA buyers — use PayPal BUY NOW button for easy buy.



professional Precision Tube Tester

Precision Apparatus TubeMaster tube tester with custom TubeSound digital plate current meter upgrade, serviced and calibrated – $600 free shipping

This Precision TubeMaster model 10-12 is a high-end professional-grade tube tester, with plate voltage as high as 300v, screen voltage supply, and variable grid voltage 0 to approx 48. Precision engineers wrote a two-page article explaining the Electronamic test method, which you can download [HERE].

Serviced and calibrated, including the installation of our custom TubeSound plate current meter upgrade. Line circuitry has been upgraded to solid-state. Shorts-Leakage performance checked. Plate current calibration checked and tweaked for best accuracy using our calibration tubes. Brand new 3-wire grounded line cord installed. Brand new rubber feet installed on case bottom.  Socket pins individually cleaned by hand to shine like-new. All new capacitors installed. All pots/switches/controls cleaned with deoxit. Best of best — we made no sacrifices. You can read my technical article about how we service this model [HERE].

This model has built-in sockets for the early 4-pin tubes up through the modern 9-pin-miniature socket, and if you acquire a socket adapter, you will have the capability to test modern compactrons, magnovals, and nuvistors. High quality and versatile tube tester, I personally feel that this Precision Apparatus TubeMaster is among the highest quality and most practical tube testers that were made.

Tester will include our remastered copy of service manual, which includes a Precision engineering document explaining the test method, and our supplement charts that are part of our remastered paperwork package. I will also email additional documents/supplements.

Precision 10-12 testing 6L6 calibration tube

Precision 10-12 testing weak calibration tube

Precision 10-12 Tube Tester with plate current meter upgrade - $600 free ship

Heathkit IT-11 Capacitor Checker

professional Heathkit IT-11 Capacitor Checker, up to 600v leakage test voltage, rebuilt & calibrated – $279 free ship USA

This is a fabulous test instrument. Here is one of the finest capacitor checkers you can buy — a professional Heathkit IT-11, rebuilt & calibrated. This unit tests capacitors out-of-circuit. Do not buy this if you are not a technician with the skills to use it. Excellent original cosmetic condition. Leakage test voltage (nominal) selectable: 3v, 6v, 10v, 15v, 25v, 50v, 100v, 150v, 200v, 250v, 300v, 350v, 400v, 450v, 500v, 600v.  Leakage calibration set according to manual: 2uA for paper, 15uA for miniature electrolytic, 2ma for standard electrolytic.

This unit also has the capability to test a capacitor at different frequencies (other than the built-in 60-hz generator) by using your external audio generator (capable of 2v output), frequency can be up to 10-khz.

Capacitance test from 10pf up to 1000uf. Resistance test from 5 ohms to 50 megohms.

Rebuild consisted of replacing all paper & electrolytic caps, installing 1% or better precision bridge reference capacitors (including variable 200pf cap for best accuracy), upgrading power supply to solid-state technology, 600v range adjusted for best accuracy at common line voltage, cleaning all switches & pots with Deoxit, installing 3-wire grounded line cord, thorough testing of features for accuracy & performance, standard cleaning inside & out, brand new alligator test leads with soldered connectors. Magic eye tube has excellent brightness.

Photos show the phenomenal accuracy and quality of the test instrument you are buying. Test capacitors and Fluke meter are shown for demonstration purposes only and not part of this sale.

testing 2.00uf capacitor

testing 0.02uf capacitor

testing 200pf capacitor

testing 200 ohms

testing 450v electrolytic with no leakage

testing 450v electrolytic with excess leakage

Leakage test voltage up to 600v

Heathkit IT-11 Capacitor Checker -- $279 free ship USA



Sylvania 620 professional Tube Tester, serviced and calibrated – $309 free shipping

Here is a Sylvania 620 tube tester, it has really clean front panel! You can tell that this machine was built by an actual tube manufacturer; it speaks of strong build quality inside and out. Large beefy transformer, quality test method (similar to a Jackson), separate tests for shorts-leakage and gas. Sylvania describes the test method as “Composite transconductance and Emission”, and seems very reliable in my opinion. I would not hesitate to make a Sylvania my “go-to” tester. Model 620 also has special circuitry for more reliable setup configuration of 600ma filament tubes (such as 6BN8, for example).

Sylvania 620 tube tester $309 free shipping

Servicing consisted of replacing most carbon resistors with new, calibration of Line-shorts-gas-emission-600ma, new 3-wire grounded line cord, cleaning all controls, switches, sockets, and pots with Deoxit.

A remastered copy of my Sylvania 620 paperwork will be included.

testing Sylvania calibration tube

testing weak calibration tube

testing NOS 6BQ5

B&K 747B mutual conductance tube tester

professional B&K 747B Mutual conductance tube tester – $499 free ship

Rebuilt & calibrated is this professional B&K 747 dynamic mutual conductance tube tester — actually, this is the newer 747B version. B&K “latest & greatest” mutual conductance tube tester! Completely solid-state — no tubes inside.  Grid leakage sensitivity of 100 megohms.  Amplifier tubes tested for dynamic mutual conductance.  Automatic line voltage compensation.  Set of four built-in pin straighteners for 7-pin-miniature, 9-pin-miniature, novar, and duodecar compactrons.

Rebuilding consisted of replacing capacitors, checking & replacing resistors, soldering the ALC bulbs directly into the circuit for best stability, cleaning all switches & pots with Deoxit, and performing calibration procedure & tweaking for best accuracy in testing my set of calibration tubes. I am also including a reprint of the owner’s manual. Original setup chart included. Like all B&K tube testers, this tester does not have any “antique” sockets, and therefore does not test any tube with less than 7-pins except for nuvistors.  It does test modern compactron tubes, such as 6LQ6, 6KD6, 6JS6C, 6LR6, 6LB6, etc… for mutual conductance.  Photo shows accurate testing of 6L6 calibration tube (tube not included).

Testing 6L6 calibration tube

BK 747B Tube Tester - $499 free ship

B&K 700 tube tester -- $409 free ship USA

B&K 700 Mutual Conductance Tube Tester, beautiful, with custom Gm plate current meter upgrade – $409 free ship.

Diligently serviced, calibration set and tweaked for best accuracy in testing of 6L6 calibration tube.

Servicing consisted of: installation of new DMM for plate current measurements during Gm tests, the pins in all 42 sockets have been individually cleaned for excellent continuity and shine close to new, #83 tube eliminated and upgraded to solid-state with fused secondary to better protect transformer plate current winding, ALC bulbs soldered into the circuit to avoid ALC continuity issues, new ALC resistors, remastered reprint on heavy cardstock of the tube setup chart just-like-original, new transformer balance pot, all control pots treated with deoxit, most caps replaced with fresh new inventory, and most carbon resistors were replaced with fresh 5% inventory, new top cap & lead, new rubber feet installed on cabinet base, brand new 3-wire grounded line cord. A copy of the BK 707 instruction manual will be included since it is pretty much the same machine.

testing 6L6 calibration tube

B&K 700 tube tester

BK 700 tube tester with custom plate current meter upgrade -- $409 free ship USA

Eico 666 dynamic conductance tube tester

Eico 666 Dynamic Conductance tube tester with custom TubeSound digital plate current meter upgrade- $375 free ship

The Eico 666/667 series of tube tester is a very well-designed, professional-grade, tube testing instrument. The machine offers selectable & separate test voltages to be applied to each tube element individually, and the meter represents the tube’s plate current (which can exceed 150ma in some configurations). I have also installed a new DMM digital plate current meter to make reading the plate current much easier than referring to the charts in the instrument manual.

Plate voltage options: 45v, 90v, 180v. Screen voltage options: 15v, 45v, 90v, grid voltage 0 to 45. Very sensitive leakage test (0 to 20 megohms). A complete series of lockouts permit the best type of shorts test to be incorporated into this tester (eliminating false shorts issues). Solid-state line for best stability. Test sockets from the early 4-pin socket up through 9-pin-miniature.

Complete service job consisted of checking all resistors for proper spec, replacing all capacitors, meticulous cleaning of all switches, sockets, and pots, calibration, installing new 3-wire grounded line cord, and installing our custom digital plate current meter upgrade.

This is an excellent test instrument if you take the time to really learn how to use it. Highly recommended. A copy of the manual will be included, and additional information will be supplied via email PDF.

Testing 6L6 calibration tube

Testing weak calibration tube

Eico 666 Tube Tester with plate current meter upgrade - $375 free ship

Jackson 648A Tube Tester – $439 free shipping

Jackson 648A tube tester $439 free ship

original Jackson hang tag

This beautiful-condition Jackson 648A is from my personal collection.  Condition is awesome, even includes original Jackson “LINE” hang tag!

Jackson 648A tube tester $439 free shipping

Professionally calibrated (both Line calibration and plate current calibration, with results compared with my calibration tubes), upgraded to solid-state Line control, brand new grounded line cord installed, all socket pins hand-cleaned for perfect continuity, plate potentiometer and all switches & controls treated with deoxit. I even polished screw heads. This model has the headphone jacks for noise-test capability.

Ideal tester for a serious buyer who will continue the proud tradition of ownership of this unit. You can’t go wrong with a Jackson, serious quality and extreme reliability. Instructions are conveniently printed inside the case lid, and I will also include a remastered copy of a Jackson supplement chart that has setup data for antique tube types. (Tubes shown in photos are to demonstrate functionality and not part of sale.)

Testing 6L6 calibration tube

Testing weak calibration tube

Testing 5AR4 audio rectifier

Supreme-manufactured I-177-B tube tester

Signal Corp I-177-B tube tester, manufactured by Supreme Inc., serviced & calibrated, $439 free ship USA.

Here is a very nice Signal Corp I-177-B mutual conductance tube tester, serviced & calibrated. This unit was built by Supreme Inc of Greenwood, Miss. Servicing consisted of replacing the #83 tube with a solid-state upgrade, cleaning all pots, switches, controls with Deoxit. Socket pins cleaned and shine very close to when new. Almost all carbon resistors were replaced with fresh modern carbon-film or metal-film 5% or better. Recapped.  Line calibration performed. Calibration voltages checked & set for accuracy (150v plate 1000 ohms/v, 130v screen 1000 ohms/v, accurate bias voltage checked at several positions of the bias pot such as -3.0 at 18R, signal voltage 5.0 vac.) Diode/Rectifier/0Z4 test functions checked for accuracy. New 3-wire grounded line cord installed. General cleaning inside & out.

Includes original tube data setup book. No other paperwork included, but instruction manual and additional supplements can be downloaded or forwarded via email.

The I-177 series is a quality mutual conductance tube tester, Hickok-style circuit, and designed for testing older tubes, pre- 9-pin-miniature. Great for antique radio servicing or tube collectors that require setup data for oddball old military tubes. Not designed for someone who only wants one tube tester, because this will not really test 9-pin-miniature or newer tubes and was not designed to do that. It does do a great job of testing the old 4-pin, 5-pin, 6-pin, 7-pin-large, etc… types of tubes. They also made an adapter that has sockets for testing oddball military/transmitting tubes (adapter not included).

testing brand new Sovtek 5881 6L6WGC

Signal Corp I-177-B tube tester $439 free ship USA

Signal Corp I-177-B tube tester made by Simpson

Signal Corp I-177-B tube tester, manufactured by Simpson, serviced & calibrated, $449 free ship USA.

Here is a very nice Signal Corp I-177-B mutual conductance tube tester, serviced & calibrated. This unit was built by Simpson. Servicing consisted of replacing the #83 tube with a solid-state upgrade, cleaning all pots, switches, controls with Deoxit. Socket pins cleaned and shine very close to when new. Almost all carbon resistors were replaced with fresh modern carbon-film or metal-film 5% or better. Recapped. Brand new (and removable) top cap clamp & wire assembly installed.  Line calibration performed. Calibration voltages checked & set for accuracy (150v plate 1000 ohms/v, 130v screen 1000 ohms/v, accurate bias voltage checked at several positions of the bias pot such as -3.0 at 18R, signal voltage 5.0 vac.) Diode/Rectifier/0Z4 test functions checked for accuracy. New 3-wire grounded line cord installed. General cleaning inside & out.

Includes original tube data setup book. No other paperwork included, but instruction manual and additional supplements can be downloaded or forwarded via email.

The I-177 series is a quality mutual conductance tube tester, Hickok-style circuit, and designed for testing older tubes, pre- 9-pin-miniature. Great for antique radio servicing or tube collectors that require setup data for oddball old military tubes. Not designed for someone who only wants one tube tester, because this will not really test 9-pin-miniature or newer tubes and was not designed to do that. It does do a great job of testing the old 4-pin, 5-pin, 6-pin, 7-pin-large, etc… types of tubes. They also made an adapter that has sockets for testing oddball military/transmitting tubes (adapter not included).

testing brand new Sovtek 5881 6L6WGC tube

Signal Corp I-177-B (Simpson) tube tester $449 free ship USA

Sprague TO-3 Tel-Ohmike

Sprague TEL-OHMIKE Capacitor Tester model TO-3, rebuilt and pro calibrated – $269 free ship.

Legendary TELOHMIKE quality, one of the kings of capacitor tester’s. Rebuilt and calibrated.  This model has bridge ranges for testing capacitors and resistors.  Servicing consisted of:

• circuit modified for 600 vdc polarizing voltage (to reduce power dissipation of voltage pot)
• plate voltage of magic eye reduced to prolong life of eye tube, and plate resistor upgraded to 1-meg pursuant to RCA specifications
• brand new 3-wire grounded line cord
• upgraded to solid-state rectifier
• recapped, including precision 1% or better reference capacitors
• Murata X1Y2 class safety capacitors across the line
• range-standard resistors for each resistor bridge range have been replaced with variable units, with precise calibration performed at center of bridge on each range
• insulation resistance calibration performed, and checked at 500-megohms, 1-gigohms, and 2-gigohms. Photo below shows eye tube just barely starting to open at 1-gigohm, which is accurate calibration
• eye tube replaced
• includes brand-new soldered test leads with alligator clips user side, spade lugs to tester
• includes our TubeSound remastered copy of user manual

Sprague Tel-Ohmike TO-3 capacitor tester $269 free ship

Outstanding tester, far better accuracy than it was originally shipped from Sprague. Photos below demonstrate testing of calibration capacitors and max output voltage. Capacitors and Fluke meter not part of sale.

testing 2.00uf calibration capacitor

testing 200pf calibration capacitor

testing 0.02uf calibration capacitor

Leaky cap

Cap without leakage

Insulation Resistance calibration

Leeds Northrup Decade

LEEDS & NORTHRUP precision hand-wound resistor decade, brass/wood construction – $69 free ship

I have never seen another one exactly like it. This is a LEEDS & NORTHRUP precision resistor decade, featuring wood case, brass contacts and brass jumpers, and hand-wound precision resistor coils. Outstanding collectors item, a true vintage American-made antique.

A brass jumper plug enables or disables each resistor, which allows very quick selection of desired resistance. Resistors are 1.0, 2.0, 3.0, 4.0, 10, 20, 30, 40, 100, 200, 300, 400, 1000, 2000, 3000, and 4000.

The 3000 (tested 3030 ohms) and 4000 (tested 4060 ohms) resistors tested very slightly high resistance, so I shunted them to bring them into almost perfect accuracy. Max resistance should be 11,100 ohms, and now tests 11,130 ohms as shown by my Fluke DMM, which is approx 0.3% error margin across the entire decade.

Leeds-Northrup resistor decade $69 free ship

Superior TV-11 Tube Tester – $159 free ship

Here is a simple “no-frills” emission tube tester, a classic Superior Instruments model TV-11 tube tester, Made in USA. Nothing fancy or complicated here, just a basic emission test circuit. Easy to use. Nice hardwood case, beautiful front panel.

Repairs consisted of performing line calibration and installing new line rectifier, emission calibration tweaked for best accuracy testing my set of calibration tubes, recapped, brand new 3-wire grounded line cord installed, cleaning inside and outside, socket pins cleaned and shine real nice.

Popular for buyers who want a cheap tube tester primarily to sort through their tube inventory and cull out the obvious duds. This tester has sockets for testing tubes with 4-pin thru 9-pin-miniature.

Paperwork includes a photocopy of operating instructions and also one original supplement chart.

testing 6L6 calibration tube

testing weak calibration tube

Superior TV-11 tube tester -- $159 free ship USA

Jackson 637

Jackson 637 antique tube tester, serviced – $199.99

Here is a real antique tube tester — a 70-year-old 1940-vintage Jackson 637 Dynamic Output tube tester. This 637 already has the 9-pin-miniature socket installed, which places the manufacture date at 1940-1941. This is a good tester for checking the old 4-pin, 5-pin, 6-pin type of tubes. Probably the newest tube that you can check on this tester would be a 12AX7, so this tester will always play a complimentary role with another tester. It would be a perfect companion to someone who already owns a “newer” tester, such as a BK 700 / 707 / 747 or any Sencore Mighty Mite or Sencore Continental.  Adding this Jackson will allow you to test those antique 01-A tubes, those #45 or #50 or #71A triodes, those 6E5/6U5 eye tubes, those #80 or #83 rectifiers, etc.

Servicing consisted of:

• upgraded to solid-state Line
• Line calibration performed
• new 3-wire grounded line cord installed
• 8 brand new quality rubber feet installed
• new capacitor
• all controls, contacts, pots, and tube pins individually cleaned
• chassis has been cleaned, and beautiful wood cabinet has been cleaned
• all cabinet hardware (latches, hinges, handle) have been polished
• I am including a copy of our TubeSound remastered copy of our Jackson 634-637 manual and charts
• the VOM capability has NOT been serviced, and should never be used in any tube tester that had VOM functions. The risk of damaging the meter is too great
• Photos below show accurate testing of our calibration tubes. Tubes not included

Testing 6L6 calibration tube

Testing weak calibration tube

Testing globe #50 triode tube

Jackson 637 with remastered paperwork

beautiful hardwood cabinet

Jackson 637 tube tester $199.99 free ship

pro KNIGHT 600C tube tester – $379.99 free ship*

Knight 600C Tube Tester $379.99 free ship

One of the most versatile tube testers you can find. This model has 13-built in sockets for versatile tube testing from the earliest 4-pin style tubes (like 01-A, #45 triode, etc…) up through modern 12-pin compactron.

• 4-pin (eg: 2A3, 83 rectifier, 01A)
• 5-pin (eg: 807, #47)
• 5-pin nuvistor (eg: 6cw4)
• 6-pin (eg: #42 pentode) with pilot lamp test socket
• 7-pin antique (large pin) (eg: #53)
• 7-pin miniature (eg: 6AU6)
• 8-pin octal (eg: 5AR4, 6550, 6L6GC, 5U4GB, etc…)
• 8-pin loctal (eg: 7N7)
• 9-pin miniature (eg: 12AX7, 12AU7)
• two 9-pin novar (eg: 7868, 6LQ6, 6JB6A)
• 10-pin miniature
• 12-pin compactron (ex: 6KD6)
• all socket pins individually cleaned for perfect continuity and shine “close to new”

Serviced and calibrated, includes professional reprint of manual and two supplement charts.  American-made.  Quality rubber feet on bottom and backside to protect your workbench.

This model uses the same industry-standard emission test also used by Heathkit, Eico, and Triplett, and in fact you can use setup charts from those other brands (with minor mental adjustment) to supplement your Knight paperwork.

Photos below show line calibration and tube test results.  Fluke meter and sample tubes are shown to demonstrate tube tester and are not part of item for sale.

Line calibration

shorts test

leakage test

Weak tube

12-pin compactron testing

6550 audio tube test

4-pin triode tube test

wood case

5881 test

Technipower 12V Regulated Power Supply

Technipower regulated 12V-3A DC power supply – $49.99 free shipping*

Technipower power supply $49.99 free ship

Technipower is the BEST of the best. Made in USA, true military & high industrial grade, “repeatable and precise”. Built like a tank. Looks like a transformer, but it is a complete regulated 12 VDC power supply. Sealed construction except for a single voltage adjustment pot accessible on the underneath. Rated at 3A output. Input is 105-125 VAC, 50Hz-400Hz. I can tell you that I ran it up on a variac, and it had strong stable output even with much lower AC input voltages. Rock solid and extremely low ripple (less than 0.2 mV measured with Fluke 179). Dimensions 7-inch tall, 5-inch wide, 4.25-inch deep. Date code 22nd week of 1983.

Original price for this power supply would have been super expensive.