Jefferson ElectricTesters
By Roger Russell
Copyright 1996-2004 by Roger Russell
All rights reserved
No portion of this site may be reproduced in whole or in part
without written permission of the author.
Tube Checker
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This early tube tester has sockets for two different size tubes. They're both 4 pin and have a bayonet type socket. The tester also has a Westinghouse 0 to 15 milliammeter. No model number for this tester is indicated. |
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The tester comes with an 8" line cord made of two separate wires
with black cloth on the outside. These are twisted together and exit the
transformer case through a porcelain grommet that says
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Instructions on the front plate are as follows: |
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1. For use only on 3 and 5 volt tubes |
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201-A Type - 7-1/2 |
199 Type - 6 |
UX Type - off the scale |
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Tubes reading below these
minimums should be rejuvenated on |
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CAUTION 1. Do not put more than one tube in device. |
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Tube Checker No. 290
Every
Set-Owner Needs One!
Tells You When Tubes Need Charging.
The No. 290 Jefferson Tube
checker is to your tubes what the hydrometer is to your storage battery. It
will test all tubes, large and small, except the UV 199 type, which can also be
tested by using an adapter. Test shows good, fair or poor tubes. Poor and fair
need charging. Full instructions with each instrument. Case finished in
crystallized green, trimmed in nickel, and equipped with cord and plug. Size 5'
long, 4" wide and 2-1/4" high. Weight 1-1/2 lbs. List Price Each
$6.00. ($8.50 list in Canada)
Tube Charger No.275
This is also called
the "Radio" Tube Rejuvenator. It comes with a 6-1/2 foot line cord
made of two separate wires with black cloth on the outside. These are twisted
together and exit the transformer case through a porcelain grommet that says
Jefferson 100 1. The other end has an old style plastic two-prong plug. The
metal case is attached to a dish shaped bottom plate that is raised around the
perimeter. The case is dark green in color. Terminals L are on the left and
terminals S are at the right. Switch position F is at the left front and B is
at the right front.
Size of the box is 3-3/8"H, 3-1/4"W (including terminals) and
4-1/8"D (including switch). For use on 110 to 120 Volts 50 to 133 cycles.
Jefferson Electric Mfg. Co., 501-511 S. Green St., Chicago, Illinois. Weight is
3.4 lbs. Date on the instructions is November 1926.
Instructions
for Operating No. 275 Tube Charger
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Charging radio tubes with the JEFFERSON
No. 275 is a simple matter and can be accomplished within twenty minutes
whether your set has one or a dozen tubes. leave the tubes in their sockets in the
set. Remove any 200 or 300 detector tubes from their sockets, because they
cannot be charged, and will burn out if subjected to the high voltage of the
flash (F). 200A or 300A need not be removed. Turn the rheostats of the set "full
on" so that there is no resistance in the circuit. If you have filament
ballast or self-adjusting rheostats in the set, remove them and short-circuit
the gap by placing a piece of wire across the brackets. Attach the two "A" battery
wires to the two terminals marked "L" for charging the large 201A,
301A, UX171, and CX371 type tubes. To charge the small 199, 299, UX120 or
CX220 type tubes, attach the "A" battery wires to the terminal
marked "S". Turn the switch to "F" and
allow it to remain there for 45 seconds. Then quickly throw the switch to the
contact marked "B" and leave it there for 20 minutes or longer. When the 20 minutes are up, yank the cord (C) and disconnect the plug at the alternating current socket. |
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The current can also be disconnected by
pushing the switch (A) on the Charger to "off" but care must be
taken not to push it too far, for if you make contact with the flash contact
"F" again, it will be necessary to charge the tubes all over again. Only tubes having thoriated filaments
can be charged. A few of the better known makes follow: Radio Corporation of America-Type UV and
UX199, UV and UX201A, UX200A and UXI 71; Cunningham C and CX299, C and
CX301A, CX300A and CX371; Stewart-Warner; Diamond; Diatron; Radio Tube
Corporation -- Type 2OIA; Sonatron -- Type 2OIA: Van Horne -- Model 5V-A;
Musselman -Model 5VA: Ceco; Gold Seal; Puratone; Supertron; Sylvania; Yale;
Kenrad; Electron. Power tubes, UX120 and CX220 can be
charged in a set having 199 and 299 tubes. If you have a combination of 3-volt and
5-volt tubes in the same circuit, charge each voltage separately. Suppose you have 199 tubes in the radio
frequency circuit with 201A and power tube UX171 in the audio circuit, charge
the 201A and UX171 first, removing the 199 tubes. Then remove the charged
tubes and replace those to be charged. Be sure to change the "A"
battery wires to the connections marked "S" for the 199 tubes. Power tubes UX171 and CX371 can be
charged in a set having 201A, 301A, 200A, or 300A tubes. Power tubes UX112 and CX112 cannot be charged. Neither can WD11, WD12, WXI2, C11 and CX12 tubes. Attaching them to the Charger, you will burn out the filaments. |
Curve
Showing the Relative Amplifying Power Before and After Charging.
Tubes wear out with
use. The fact that they still burn is no indication of their ability to amplify
the broadcast. After being in service for a period, the thorium atoms, on the
surface of the filament, which carry the current to the plate, are consumed.
There are more thorium atoms in the tungsten filament, however, which can be
brought to the surface by charging. The chart above shows the difference
between the amplifying power of a tube fully charged and operating at highest
efficiency, and a run down tube. Charge your tubes once a month to keep them
always at highest efficiency.
The vertical scale shows plate current in milli-amperes from 0 to 8. The
horizontal scale shows grid bias volts from -12 to +12.
Jefferson Combination Testers
This is a number 28
combination tester. It's 4-1/2" high (including fixtures), 5-7/8"wide
and 10-1/2"deep. Spark coils can be pushed into the opening at the top and
connections are made with contacts on the inside of the tester.
This tester operates on
110V 60 CY. There are also sockets for testing lamps and spark plugs. The
tester is supplied with a lamp socket connector instead of a normal two prong
plug.
The tester is made of mahogany.
From
Bulletin 300 August 1918
This is the modern
method of testing automobile lamps, spark plugs, electric horns, battery jars,
Ford coil units and other types of coils for locating short circuits, grounds,
etc.: and for starting Ford engines in cold weather.
Jefferson Combination Testers are so completely different with their many
different attachments that they immediately become a necessity and a money
saver to every dealer, garage and service station.
The important
features of these testers are as follows:
1st. They are so flexible that in general garage-testing work there is hardly a
problem they will not solve.
2nd. They are as compact, trouble-proof and simple to operate as they are
accurate and reliable.
3rd. Wherever alternating current is available the No. 17 and No. 28 testers
can be directly connected tothe lighting circuit, thereby eliminating the use
of storage batteries or dry cells.
Furnished in Four Styles
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No. 16 Combination Tester for battery current |
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$8.00 |
Jefferson testers are assembled in cases of highly polished mahogany. All
metal parts are heavily nickeled, presenting a very handsome appearance. The
No. 28 and No. 17 testers are equipped with extension cord and plug so they can
be conveniently attached to any alternating current lighting circuit.
Standard stock windings Nos. 17 and 28 testers will operate on 100 to 120
-volt A. C. 60 to 133-cycles. 110-volt, 25-cycle, 220-volt, 60-cycle or
25-cycle carried in stock and can be furnished at an additional cost of ten
percent to net price. When ordering be sure and specify voltage and cycle
current required.
Jefferson Electric Mfg. Co.
426-430 South Green Street
Chicago, Ill.
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About This Site |
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More text and pictures about Jefferson will be added as my research continues. Any comments, corrections, or additions are welcome. |
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Created by Roger Russell |