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In 1920 three men, all expert glass blowers, opened one of the most successful independant lamp plants in the country. The lamp company founded was the Brite Lite Lamp Mfg. Co., Inc. President, George Coby; secretary and treasurer, Ely Egnatoff 11; John N Otar. The plant was at 214 Oxford St, Providence, RI. 10
 Providence Journal May 19, 1920
 Electical Record July 1920
 Click to enlargeActs and Resolves Passed by The General Assembly of The State of Rhode Island and Providence Plantations January 1920
In 1923 Brite Lite Lamp had to defended themselves for patent infringement by General Electric. They were unsuccessful. 14
 Official Gazette of the United States Patent Office June 1923
In 1925 there seems to be come trouble between Ely Egnatoff 11 judging from this court case.

Providence Journal February 4, 1925

The Electric Lamp Industry By Arthur A Bright Jr, 1949

The Federal Reporter September-October, 1923
With prosperity, both General Electric and Westinghouse became interested in the businees. Eventually General Electric bought the business. George Coby, Ely Egnatoff 11 and Willian Cepek next ventured into the Radio Tube Business and founded the first indepenant radio tube company in this part of the country. 5
In 1928 the executive officers of the Triad Tube Company of Pawtucker, RI were George Coby, president, Ely Egnatoff 11 (one of the principals of the CeCo tube company), treasurer, Harry Steinle, vice-president and general manager, and Willian Cepek (another principal of the CeCo tube company), secretary. At that time they were the largest indepentant tube factory in the Country.
The engineering staff included S U Marie, PHD, Roger Williams, PHD, A S Friedman 12, BS, and Gregory Ryisky, EE ME, in addition to graduates of the foremost technical and engineering schools in the country. 2
The connection with CeCo tubes comes from an agreement that Egnatoff 11 and Cepek, made when they sold the company, to not manufacture tubes for one year. So, they moved across the river to Pawtucket and manufactured Triad Pens, which were triangular pens that wouldn't roll off the table. Apparently, the lure of radio tubes was too much because in June 1929, Triad announced their new line of radio tubes in a distinctive triangular box. Immediately successful, $1,000,000 in sales was reached in the first year. 3
Radio Doings October 1927
Pawtucket Times February 1, 1929
Providence Journal February 2nd, 1929
Providence Journal February 16, 1929
Hartford Courant March 17, 1929
Pawtucket Times February 27, 1929
On February 28th, 1929, Triad filed a trademark for the Roytron logo for vacuum tubes produced under that name.

Roytron tradmark record
Official Gazette Of The United States Patent Office Volume 393 April 1930
Iit is also believed that Triad made tubes for other companies. The tell is the printed tube number on the side of the base. Here is a Kadette and Halson example.
 Pawtucket Times March 12, 1929
 Radio Retailing May 1929
 Pawtucket Times May 4, 1929
 Pawtucket Times June 26, 1929
Official Gazette Of The United States Patent Office July 23, 1929
 Radio Broadcast July, 1929
 Pawtucket Times July 27, 1929
In September 1929, Triad a 250 percent increase of employment since opening the plant..
 Click to enlargePawtucket Times Saturday September 7, 1929
 Click to enlargePawtucket Times Saturday September 7, 1929
 Radio Broadcast September, 1929
In October 1929, Triad executive Harry M Steinle, Vice President and General Sales Manager takes to the air waves to promote the Triad Business.
 Pawtucket Times October 7, 1929
 Pawtucket Times November 1, 1929
In 1929 Triad reports large business during the year.
In May 1929 Triad holds it's first annual dinner for their employees.
 Pawtucket Times May 24, 1929
In June 1929 students from Pawtucket Senior High visit the plant.
 Pawtucket Times June 12, 1929
 New York Times July 28, 1929
In February of 1929, Triad is expectedto move into a new plant at Fountian Street and Blackstone Avemue.
In December of 1929, Triad is completing arrangments for its new plant at Fountian Street and Blackstone Avemue. 15
 Pawtucket Times December 31, 1929
In 1930 Triad made a deal with RCA to build tubes under their present and future patents. 8
 Pawtucket Times January 14, 1930
 Pawtucket Times February 8, 1930

Radio Doings February 22, 1930

Rhode Island School of Design The Student Designer March 1930

Broadcsst Weekly March 2, 1930

Pawtucket Times April 23, 1930
In 1930 production was on the increase in the new Triad plant in Pawtucket, RI. According to president George Coby more than 600 people were on the payroll. The factory has increased floor space and mechanical facilities. Reactions at Radio trade shows in New York, Chicago, Boston and Philadelphia have proved to be highly encouraging. 4
In May of 1930, Triad tubes are picked by the Detroit Police Department becaus of their resistance to the shocle and jars of the sets in the Police cars.
 Click to enlargePawtucket Times Saturday May 3, 1930
 Pawtucket Times July 12, 1930
 Radio Doings July 19, 1930
 Triad T-45 Tube Used in Court Case 7/9/30 History Curtesy of Joe Gruber 13
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 Evidence Tag Used in Court Case 7/9/30 History Curtesy of Joe Gruber 13
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 Click to enlargeRadio, August 1930
In August of 1930 there was fire in the plant in the carbonizing room

Pawtucket Times August 26, 1930
 Click to enlargeProvidence Journal April 17, 1932
 Pawtucket Times February 10, 1932
 Pawtucket Times January 19, 1933
 Click to enlargePawtucket Times August 18, 1933
In 1933 there are Trademark refences to the Meltron Tube company as being a psrt og Triad.
 Providence Journal April 23, 1933
 Index Of Trade Marks 1933
 Index Of Trade Marks 1933
 Index Of Trade Marks 1933
 Index Of Trade Marks 1933
 Official Gazette of the United States Patent Office Volume 429 April, 1933
 Radio Weekly September 26, 1934
 Pawtucket Times December 14, 1934
 Pawtucket Times January 5, 1935
TRIAD METAL SHEILDED RADIO TUBES
SERIES MG
TECHNICAL BULLETIN
TRIAD MANUFACTURING CO., INC. - PAWTUCKET, R. I. - U.S.A.
This comes from the RMA registration notice on Triad's line of metal-glass tubes, on Release 34 in July 1935. It came out a month or so after others brought out glass contenders versus GE's and RCA's "original nine" metal types. It covers the nine, plus the orphaned 6D5. It cleverly aids the construction of AC-DC series-string sets by adding the 25Z5 MG rectifier and 43 MG output tube. There are also two plug-in ballast lamps to replace "curtain burner" resistance cords or other resistors . . giving what looked like an extra tube in the radio. - Ed.
Triad Manufacturing Company is pleased to announce a new line of tubes known as the MG series. Consistent with its established reputation for progress and individuality, Triad has produced a non-breakable, fully shielded, metal tube in which a newly developed glass is used for maintaining the vacuum. By this method the same vast experience accumulated in several decades of lamp and radio tube manufacture, is not suddenly upset and consequently, the Triad series MG will have the same long and serviceable life that has characterized properly made glass sealed tubes in the past.
Certain highly publicized so-called metal tubes now available, consist of a series of glass to metal seals in addition to several metal to metal welds. By this construction, the overall height of certain tubes is reduced but it is the contention of the Triad Engineers that the series MG described herein offers the same technical advantages, a greater sales appeal, and less inherent risk to the manufacturer adopting these types. It should be further noted, that the Triad series MG is not a line of tubes for some indefinite date in the future. Equipment has been installed during the past several months to produce 10,000 of these tubes per day for immediate delivery to manufacturers adopting the Triad line. This new line of tubes has the further advantage of being designed such that it is fully interchangeable with the existing metal tubes. The new standard octal bases are used throughout and base wiring is in accordance with the standards of the Industry.
As a further advantage, the manufacturer is offered four additional types for AC-DC uses. These types have the same characteristics as the corresponding glass types, but they have been re-designed to conform with the metal tube series.
The rating and basing arrangements of the MG series will be found elsewhere in this bulletin. A brief description of the MG types may be of help in becoming familiar with the new type numbers.
5Z4 The 5Z4 is a cathode type, full wave rectifier having low voltage drop for general use. It has approximately half the voltage drop of the corresponding glass type 80. Heater and cathode are tied together internally.
6A8 This tube is essentially the same as the type 6A7, except for the additional pin tied to the external metal shell.
6C5 This tube is a triode detector-amplifier very similar in characteristics to the familiar 6C6 when the latter is connected as a triode.
6D5 The 6D5 is a power amplifier triode. Its characteristics are quite similar to the type 42 when the latter is connected as a triode.
6F5 This high-mu triode is practically the same, so far as electrical characteristics are concerned, as the triode section of the familiar type 75. The grid connection is brought out through the top cap.
6F6 The metal type 6F6 is electrically similar in all respects to the type 42 when employed as a pentode power amplifier.
6H6 This double diode is designed to provide for AVC and diode detection. It is similar in every respect to the double diode section found on multipurpose glass tubes except that both cathodes are brought out separately.
6J7 This hi-mu pentode detector amplifier is similar electrically to the type 77.
6K7 The 6K7 is a triple grid variable mu amplifier similar to the well-known type 78.
25Z5 MG This special type is provided to fill the need of a rectifier for AC-DC sets and is similar electrically to the type 25Z5.
43 MG This type has characteristics identical to the 43 and provides a power output tube to complete the AC-DC line.
50A2 MG This is a ballast tube in a metal shell with a tap to supply two #40 pilot lights in series.
50B2 MG The 50B2 MG is designed for the same service as the 50A2 MG but tapped to supply a single #40 pilot lamp. Both ballast tubes have an overall voltage drop of 50 volts and are employed in transformerless receivers for AC-DC voltage. For example a 25Z5 MG rectifier, a 43 MG power output tube, a 6K7 R.F. amplifier and a 6J7 detector comprise a typical compliment [sic] for ballast tube operation. This listing of metal shielded tubes should not be considered complete, but simply the list of types which are now in production. Considerable experimental work is being done on various types of metal shielded tubes at Triad. When this experimental work indicates that additions or changes should be made to our production types, improvements will be incorporated.
With the innovation of the new series MG tubes, it is assured that most of the basic and essential experience gained from glass tube processing will be incorporated in the making of the new metal glass tubes. These facts cannot be over look [sic] so readily, in view of the widespread use and acceptance of the glass tubes. Combining this knowledge with the new principle of metal tube design, a most permanent and useful series of radio tubes has been developed.
About the same time, Arcturus put out its "Coronet" series (covered in TC, August 2016 and April 2017), a similar glass-in-metal line with adapters to "modernize" existing radios. (The radio manufacturers don't seem to have bought this series.)
Triad added a few MG types, like the 6N5MG and 6Q7MG. A few radios were all-MG. The Silvertone models 1909, 1912, and 1962 sported a 6A8MG, 6K7MG, 6Q7MG, 6C5MG, push-pull 6F6MGs, and a 5Z4MG. Hytron also sold some MGs like the 6J7MG and 6K7MG, possibly made by Triad. So did KenRad (a 6A8) and National Union (a 6Q7MG)
However, when Triad brought out its "Triadyne" group of output tubes (dual triodes with a cathode follower vigorously driving the output side) in 1935-37, they were glass types. These were the 6B5, 6AB6, 6AC5G, 6AC6, 25B5 and 26N6G. (There may have been a few MG versions of the 6B5 and 6N6G.) In any event, their June 1937 product list shows nothing "MG" or metal in any other form.
In regard to the ill-fated 6D5, RCA designed it and did some pilot production. However, a manual scan of the 1938 Mallory-Yaxley Radio Servicing Encyclopedia shows nothing using the tube. Use of the "Radio Finder" search feature of John Okolowicz' www.grillecloth.com automatically searches it and two other data bases, and gives the same answer. However, there was one known ap plication. The 1937 edition of the Jones Radio Handbook (Frank C. Jones, editor) shows a "metal tube 5-meter transmitter-receiver" in which the transmitter is push-pull 6D5s! "The 6D5s are similar to glass type 45s."
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Tube Number | Have | Discription |
5Q7 MG | | |
5Z4 | | Cahtode Type, Full Wave Rectifier |
6A8 | | Pentagrid-Converter (Heptode) |
6C5 | | Triode Detector-Amplifier |
6F5 | | Hi-Mu Triode |
6F6 | | Pentode Power Amplifier |
6H6 | | Double Triode |
6J7 | | Hi-Mu Pentode Detector Amplifier |
6K7 | | Triple Grid Variable Mu Amplifier |
6N5 MG | | |
6N6 | Yes | Power Output |
25Z5 MG | | Rectifier |
43 MG | | Power Ourput Tube |
50A2 | | Ballest Tube |
50B2 MG | | Ballest Tube |
In July, 1936 Ely Egnatoff, one of the Triad Founder, dies.
 Pawtucket Times Pawtucket Times July 29, 1936
 Pawtucket Times Thursday July, 30, 1936
 Woonsocket Call Thursday July, 30, 1936
 Pawtucket Times October 10, 1936
 Radio World January 1937
 Click to enlargePawtucket Times April 1, 1937
 Providence Journal April 2, 1937
 Click to enlargeWoonsocket Call April 2_ 1937
 Providence Journal April 3, 1937
 Woonsocket Call April 3, 1937
 Pawtucket Times April 5, 1937
 Pawtucket Times April 15, 1937
 Providence Journal April 21, 1937
 Pawtucket Times April 21, 1937
 Providence Journal April 26, 1937
 Providence Journal April 28, 1937
 Woonsockt Call April 28, 1937
 Pawtucket Times April 28, 1937
 Pawtucket Times August 2, 1937
 Click to enlargePawtucket Times September 9,1937
 Pawtucket Times August 22, 1938
 Click to enlargePawtucket Times April 17, 1939
 Pawtucket Times August 14, 1940
 Pawtucklet Times October 23, 1940
 Pawtucket Times January 21, 1941
 Pawtucket Times January 19, 1946
Pawtucket Times December 17, 1953
 Click to enlargeWoonsocket Call February 14, 1958
 Click to enlargeWoonsocket Call September 10, 1958
 Click to enlargeWoonsocket Call November 26, 1960
In June of 1965 we find an article in The Miami News of The Triad Tube Corporations moving into a new 15,000 square foot plant and headquarters in Sunshine State Industrial Park in North Dade. The company at that time is described as an electronics wholesaler distributing vacuum tubes for radio and television sets, selling through discount chain stores and for the industrial market. Their president Frederick M Bender said they moved from Hialeah to expand their facilities to meet the firms goal to get "at least one per cent of the annual 400 milion dollar vacuum tube replacement market." 9
On January 1st 1975, in the state of Florida the Triad Tube Corporation was setup. Its location was 71 NW 25th Street in Miami Florida. President, Director was William S Kirk, Director Susan D Kirk, Director Joseph D Weatherby. The company was involuntarily desolved in April, 25th 1978. 7


 Click to see how Triad tubes were made
Radio Craft, June 1932

This is an automatic grid winding machine. Two heavy support wires are run through a revolving head - at the extreme left of the picture. As these two support wires revolve, being driven by the motor which operates the revolving head, they pick up a fine wire which is run at right angles to the support wires and is equally spaced along the support wires. The spacing is automatically controlled for any particular type of tube for which the grids are to be used. This makes one long grid, the entire length of the support wires.
- Radio Craft, June 1932
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Cage Assembly - The operator is using a foot-controlled electric welding machine. The upper arm of the welding machine makes contact with the metal elements which the operator is holding.
- Radio Craft, June 1932
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Cathode Assembly - Here the operator is shown placing the special alloy filament wire into the Isolantite insulating sleeves.
- Radio Craft, June 1932
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Cathode Spraying - After the operation shown in Figure No. 3, groups of the individual cathodes are placed in a spraying hood and given a coating of prepared chemicals by means of the spray gun which the operator holds in her right hand. The performance and the ultimate life of the heater-type tube depends, to a very large degree, upon the uniformity of the spraying mixture itself as well as the uniformity with which it s applied.
This is one of the most important operations of the cathode.
- Radio Craft, June 1932
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Hydrogen Furnace - All of the small parts which have been shown in the foregoing photographs, as well as any other metal which is contained inside the glass envelope of the tube, are placed in this furnace before being assembled.
- Radio Craft, June 1932
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Automatic Flare Machine - Long lengths of glass tubing are placed in the revolving chucks which are shown at the top of this machine. These chucks feed the glass tube, at a predetermined, desired length, into a number of gas flames. There are eight sets of gas flames which the tube passes through from the time the operation starts until the flare is finished. Each different position is accompanied by an increase of temperature of the flame acting upon the glass tubing as the process develops. At the position shown directly before the operator is a revolving steel flare cutting disc.
- Radio Craft, June 1932
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Stem Machine - The operation shown in this picture is worked out in six different positions which are automatically rotated by the machine. The result is the inserting of the necessary lead wires which connect the elements of the tube to the prongs of the tube base, which in turn goes into the socket of the radio receiver. The small glass tube, which is shown in the operators hands, is used in a later operation for evacuating the entire tube. It joins the flare at a point where the lead wires are sealed into the glass.
- Radio Craft, June 1932
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Automatic Stem Bender - Stems taken from the machine shown in Figure 7 are then placed in this device which is controlled by a foot-operated clutch. When this machine is operated all of the lead wires are cut to the proper length.
- Radio Craft, June 1932
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Mount Assembly - The operator in this picture is using a machine similar to the one shown in Figure No.2. The difference lies in the fact that all of the assembly which has been finished by the process shown in Figure No.2 is now joined to the rest of the elements, making a complete "Mount," ready for inserting into the glass envelope or bulb.
After the "Mount" is completed, the unit goes to the sealing-in" machine.
- Radio Craft, June 1932
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Mount Assembly - The machine here is somewhat similar to the flare-making machine in that the operation includes passing the elements for the tube through a number of gas fires of gradually increasing temperatures.
- Radio Craft, June 1932
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Exhaust and Sealing Machine - The entire tube assembly is run through this machine in such a manner as to drive off all of the gases and pump them out along with all the air in the bulb. The heavy coil of wire directly above the heavy insulated lead wires, is a high frequency coil, used for heating the elements within the tube, while it is being evacuated. The heat of the elements is produced purely by the inductive effect of the high frequency current passing through the coil. A "getter" explodes, giving a "silvery" appearance.
- Radio Craft, June 1932
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Automatic Basing Machine - Here, the completely evacuated and sealed assembly, taken from the former operation, is attached to the base. The base is already fitted with the requisite number of tubular metal prongs. The lead wires are put through these tubular prongs, by the operator, before the tube and the base are placed in the basing machine. The base, itself, is filled with a specially prepared cement. These assembled units are then put through a circular oven, which is held at a constant temperature.
- Radio Craft, June 1932
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Aging Rack - This highly interesting section of the production line indicates, by means of the banks of ordinary incandescent lamps, just exactly the condition of each tube as it comes through production. The finished vacuum tubes are placed in sockets which are connected to normal operating voltages. The current is then turned on and each tube has to be aged for a given period at specified voltages. If there is a short circuit between a plate and grid of one of the tubes, one of the lights in the bank to which that particular tube is connected indicates that fact to the oper ator. Other lights detect other troubles. This is true of any other flaws which might take place in the tube and the operator is therefore able to throw out those that are faulty.
- Radio Craft, June 1932
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Test Table - A table, of this character, is at the end of each production line. It is fitted with nine delicate meters and is used to measure ten different characteristics of each tube. These test tables are of the very latest design and are the work of the Triad Engineering Staff.
- Radio Craft, June 1932
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Packing - All of the highly developed Engineering work in a modern tube plant can be knocked into a "Cocked Hat" if the tubes are not satisfactorily packed. After shipping millions of tubes to all parts of the world the Triad Company has standardized on a system of wrapping.
- Radio Craft, June 1932
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In 1929 NBC stations carried The Triadors, Friday evenings at 8:00. The slogan for the show was: "There is a TRIAD tube for every radio need. "Ask for the tube on the black and yellow triangular box.".

Click to enlargeTriad Triadors Flyer Triadrama No. 15 Cleopatra Walks the Nile For a Camel November 1, 1929
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Click to enlargeTriad Triadors Flyer Triadrama No. 15 Cleopatra Walks the Nile For a Camel November 1, 1929
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Click to enlargeTriad Triadors Flyer Triadrama No. 16 Ulysses Knocks a Homer November 8, 1929
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Click to enlargeTriad Triadors Flyer Triadrama No. 16 Ulysses Knocks a Homer November 8, 1929
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Pawtucket Times July 6, 1929

Pawtucket Times September 6, 1929

Pawtucket Times October 5, 1929

Pawtucket Times October 15, 1929

Pawtucket Times September 7, 1929

Pawtucket Times September 13, 1929

Pawtucket Times October 18, 1929

Pawtucket Times November 1, 1929

Pawtucket Times November 22, 1929
Tubes & Boxes
Triad Tubes Famous Triangular Box for a T01A, 1929

T-45 Tube in Triangular Box
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T-45 Tube in Triangular Box
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T-45 Tube in Triangular Box
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T-45 Tube in Triangular Box
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T-45 Tube in Triangular Box
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T-45 Tube in Triangular Box
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Large and Small in Triangular Box's
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Large and Small in Triangular Box's
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Large and Small in Triangular Box's
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T-26 Made in July 1929
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T-26 Made in July 1929
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T-01A
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T-01A
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T-01A
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T-01A
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224
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Crosley 26L6 made by Triad ~1936
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Triad T-71A
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Triad T-71A
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Triad 227
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Triad 227
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Assorted Triad Tube Boxes
 Click to enlargeTriad Type T26 Tube This actual example has a FBI stamp in the cover. Possibly used in the investigation of counterfit tubes.
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 Click to enlargeTriad Type T80 Tube This actual example has a FBI stamp. Possibly used in the investigation of counterfit tubes.
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 Click to enlargeTriad Type T80 Tube This actual example has a FBI stamp. Possibly used in the investigation of counterfit tubes.
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 Click to enlargeTriad Type T80 Tube This actual example has a FBI stamp. Possibly used in the investigation of counterfit tubes.
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 Click to enlargeTriad Type T80 Tube This actual example has a FBI stamp. Possibly used in the investigation of counterfit tubes.
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 Click to enlargeTriad Type T80 Tube This actual example has a FBI stamp. Possibly used in the investigation of counterfit tubes.
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 Click to enlargeTriad Type T80 Tube This actual example has a FBI stamp. Possibly used in the investigation of counterfit tubes.
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Ads and Articles
Radio Retailing Ads
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 Click to Enlarge Pawtucket Times September 26 1932
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 Click to Enlarge June, 1930 |
Tip-Top Tubes
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