Triplett 3444 tube tester and analyzerTriplett 3444 tube  tester and analyzer rebuilt/calibratedTriplett 3444 Tube Tester/Analyzer - Total Rebuild with military/industry grade parts, 120 hour burn-in, Refurbished & Calibrated. New signal and meter tubes included.12 month warranty on part...1795.00

Triplett 3444 tube tester and analyzer rebuilt/calibrated [Expired]

no longer for sale

Triplett 3444 Tube Tester/Analyzer -  Total Rebuild with military/industry grade parts, 120 hour burn-in, Refurbished & Calibrated. New signal and meter tubes included.

12 month warranty on parts installed. This analyzer should need no further service for 10 or more years, perhaps as long as 20.

After the sale help on testing by phone or email

One of the Best Tube Tester Analyzers ever Produced in the U.S.A.

Preferred over Hickok testers by the Navy, Air Force, FCC, FAA, radio and TV stations, commercial air lines, and more.

Most all Testers Sold including eBay, require a $300-400 Refurbishment/Calibration, and many times higher bills for a total rebuild which this analyzer has received.

Analyzer details:

Direct Gm Readout From 0 to 30,000 Micromhos on clearly marked scales.

Read dual element tubes such as a 12ax7 with the flip of one switch.

NEW Replaceable socket savers for the octal, 9 and 7 pin sockets (above bias dial, under the cover)

Four balanced bridge rectified and capacitor filtered Plate & Five Filtered Screen Voltages from 12 to 250 VDC

Bias Voltages; -5 to -50 VDC fully adjustable

​Four fixed Grid Signals 33, 100, 333, 1000 Millivolts AC, at 5,000 Hz (independent tube circuit generated).

23  selectable AC Filament Voltages

Plate Current Readout on Main Gm Meter on either the 5ma or 50ma scales

Leakage Readout on Main Meter; 0-10 Mega ohms not just some simply short as most testers such as Hickok.  This is of major importance.

Gm Meter isolated From direct Gm circuitry by Its own micro-ammeter 12au7 circuit.

Gm Circuitry calibration on-the-fly, Self Check Feature for most accurate readouts.

​Tested Under Voltages Encountered in Real Life Applications and at manufacturers 1A data points.

Tests Most Old and New Tubes with highest and repeatable accuracy.

Sockets for 4,5,6,7 Pin tubes, Octal, Loctal, 7 and 9 Pin Miniature, 7 and 8 Pin Subminiature, 5-Pin Nuvistor

Built-In 7 & 9 Pin Straighteners

Noise Test Jacks

Illuminated Main Gm Meter and Roll Chart

DC Overload Warning Lamps

Will not test high power transmitter triodes such as the 845 or 211.

​Copy of Operating Manual includes, plus our quick and easy testing methods primer.

Case is in good condition showing average wear and tear, see pictures.  Deck is in very good condition with some minor spotting and marks.

Below is a detailed account if you wish to read additional information:

One of the finest tube analyzers ever made. Measure transconductance/gm and match plate current with high repeatable precision. An opportunity to verify what you buy or sell, or keep tabs on your tube and amplifier investments with total confidence and no guessing. This rebuild and calibration is good for a minimum 10,000 hours of actual in-service testing use before any 'check-up' should even be considered, that is about 20 years for most users. Your tubes are tested in class 1A conditions as per tube manufacturers data plate curve references.  Installed parts and labor are guaranteed for one year. Specifications are at the end of this listing.

Note that there are two different Triplett 3444 being offered, please see each one

 This is a very easy to operate machine, you set the dials according to the numbers on the roll chart, verify the meter setting and after the tube warms, and read your gm and direct plate current readings at the same time.  This is true plate current measured as a triode. Dual element tubes such as 12xxx can be tested without changing any knobs as you must do on Hickok and others. 

If testing is new to you or you have years of experience, we prefer on line or telephone support to get you going and demonstrate subtle details the manual does not cover.  We also provide a primer, a Cliff's Notes, that is easy to understand. After the fact help is always available. Have some rare tube and there is no set up for it, we will help create the set up values for you. Keep in mind that the 3444 can not test high power transmitter tubes, but nearly all other tubes it can test.

This TRIPLETT MODEL 3444 LABORATORY TUBE ANALYZER has been completely rebuilt and calibrated to the exact original 25 page factory standards calibration document and assembly master model. To the best of our knowledge, no other service has this document.  ALL testers are burn-in for over 72 hours and retested to re-verify calibration to 1% or less (Triplett allows 3%) and adjusted as needed. The actual meter is tested for full scale deflection at the given spec. The 'line' test calibration alone takes up to THREE DAYS to resolve. The highest and finest grade components were used including low current leakage capacitors, Vishay military grade resistors, and new old stock tubes. We measure ALL actual component values before insertion and use. It has a Triple calibration verification before it leaves here.

We have been in business since 1973 as C. G. Industries of Florida (  We refurbish and restore vacuum tube testers, modern and vintage tube equipment and amplifiers, hot-rod and custom reworks included. We don't mess around and are very serious about our services. Please check our Audiogon feedback for members who have bought a tester from us or had their tester serviced.  On Ebat we are known as budngreg with a 16 year history of 100% five star service.

Paypal to confirmed address only.   We will also accept checks which need to clear.

Why is this ANALYZER considered better than the Hickok tester series (or Western Electric)? Answer: All Hickok tester are based on an early 1940's design. All Hickok testers use two tube based rectifiers, and unless the pulsed DC from each side of each tube is always equal (near impossible unless balancing circuits are installed which we have created for Hickok testers) the differences are shown on the gm meter as a plus or minus of actual gm tube value and the higher the bias setting the worse is the error. Only the Hickok 539C attempted to correct this problem. The Triplett 3444 has no issues like this. Hickok also used a 60hz power-line signal, the Triplett uses a 5000 Hz internal generated signal. Many low end Hickoks' can damage frame grid tubes, the 3444 can not. Most Hickok testers do not detect 'short' or leakage above 300,000 ohms and most use a neon bulb not a meter, the Triplett 3444 detects from a zero ohm short to 20 million ohms leakage on the meter (we would never use a power tube showing less than 2 million ohm leakage and most Hickok will miss that altogether). Hickok have only 150 unfiltered D.C.volts or less on the B+ plate and on a power tube it can be down to 120vdc, Triplett used 250 fully filtered D.C.  volts. There is good reason why industry, the military (Navy and Air Force) and government agencies such as the FAA turned to the Triplett 3444 in the 1960's and thereafter. This 3444 is likely the finest vacuum tube tester ever made.

Technical specifications for the Triplett Model 3444

Four direct reading Gm ranges
1,000 micromhos
3,000 micromhos
10,000 micromhos
30,000 micromhos
Four signal potentials 5000Hz
1000 millivolts
333 millivolts
100 millivolts
33 millivolts

Filtered DC, 85 volts. In accordance with EIA G-8 Committee recommendations.

0 to 10 megaohms at 85 volts (measurements made directly on the meter).

Four filtered DC plate potentials.
12 volts
30 volts
100 volts
250 volts

read on the tester meter at up 5ma and up to 50ma selectable scale

Two filtered DC bias ranges (on 50 division dial so that actual bias voltages can be read
0 to 5 volts
0 to 50 volts

Five filtered DC screen potentials
12 volts
30 volts
45 volts
100 volts
250 volts

Twenty-three AC voltages closely regulated:
.63 volts
1.25 volts
1.4 volts
2.0 volts
2.35 volts
2.8 volts
3.15 volts
4.2 volts
4.7 volts
5.0 volts
6.3 volts
7.5 volts
8.4 volts
9.5 volts
10.5 volts
12.6 volts
16.8 volts
18.9 volts
26.0 volts
35.0 volts
50.0 volts
70.0 volts
117.0 volts

Self checking GM circuit with 5 kHz signal source and vacuum tube micrometer.

Grid current test under operating conditions.

Cut-off measurement on voltage amplifiers.

Test for rectifiers emission is made under load.

Single element switching set up for dual purpose tubes, such as 12ax7.

Firing voltage grid current and cut-off measurements in a thyratron.

Output 1.5 volts, 5000Hz.

Rugged 200 micrometer, illuminated, with 4" scale length and knife edge pointer. (Verified)

Noise test jacks for checking noisy or intermittent tubes.

Roll chart illuminated and removable.

Combination 4-5-6 prong; combination 7 prong; octal; loctal; 7 pin subminiature; 8 pin subminiature (round); 7 pin miniature; 9 pin miniature; nuvister on serial number above 3,000; acorn adapter (supplied with analyzer - stored in roll chart compartment). Octal, 7 pin miniature, 9 pin miniature are socket-savers for easy replacement from the panel.
9 pin straightener die on panel.
Wood, leatherette covered
Red bulb lights with excessive overload.
3 amp, 250 volt, type 3AG in roll chart compartment.
Power 120 to 124 vac


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