P.R. Mallory & Co. 1933-34 Schematic

P.R. Mallory & Co. 1933-34

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Product Information:
Model:1933-34
Manufacturer:P.R. Mallory & Co. (Elkon)

Schematics Content

Page 1:

(j) Loosen the locking screw of the stop post (identified at point 3, on diagram 1) and adjust the stop post (identified at point 4, diagram 1) so that the tip of contact spring assembly engages screw-side of stop post head, allowing contacts to meet with a light pressure. This stop post is easily adjusted by turning to left until head of contact post pulls contact on left, or contact spring, away from contact on right, or reed contact. Then turn stop post screw to right about 1/8 to 4 turn, until contact points meet the light pressure. At this point, stop post locking screw should be firmly tightened down to hold stop post in this position,

(k) If the foregoing mechanical adjustment has been carefully followed out the Elkonode is now ready for Electrical Tests. These tests should be conducted with a master Eliminator, into which the Elkonode can be inserted while the can and rubber cushion are still removed, and with a "dummy" load on the Eliminator which will require 180 volts at 35 m.a. for Elkonode types 6, S101, S102, 5103, S111, and T112. The output of the Elkonode is adjusted by increasing or decreasing the air-gap clearance between pole-piece of coil and surface of the armature reed. A cam nut and locking screw arrangement provide a flexible adjustment which sometimes must be supplemented by inserting thin metal shims between coil and bracket. NB - Shims are required only where construction of the unit will not permit air-gap clearance being decreased to point required, by adjustment of cam nut.

(l) Electrical adjustment for other types of Elkonodes, from 1 to 5 inclusive, must be conducted with "dummy" load to equal maximum output available from whichever type Elkonode is involved per characteristics shown in the foregoing table.

(m) Extreme care must be exercised to insure that no dirt or foreign matter is allowed to accumulate on contact points and that entire Elkonode assembly is kept thoroughly dry.

(n) Excessive sparking usually results from improper pressure between and alignment of contact points. If it is found necessary to bend the reed to secure a flat alignment of points, this should be done very carefully, using a pair of thin flat nosed pliers, to grasp the reed firmly at the base where it is mounted. A very slight pressure at this point will be required to change the angle of contact for vibrator points. No sparking whatever results from improper adjustment of stop post, permitting contact springs to follow reed springs past the center of cycle of amplitude or arc of vibration. Contacts should be lightly touching when at rest so there is about 014 inch clearance between stop post and contact spring. Stop post will then break this contact at the center of cycle of amplitude.

If the foregoing instructions are followed carefully, and if reliable instruments are used to measure the output of the Elkonode when electrical adjustments are being completed, you should be able to install contact and reed spring assemblies without difficulty. When adjustments have been completed to your satisfaction, place vibrator assembly inside rubber cushion by holding cushion in inverted position, and allowing assembly to drop into place. Next, place entire assembly inside can, in same manner, and fasten can to base, using screws provided for that purpose.

Thorough instructions for servicing other parts of the Mallory Elkon "B" Eliminator are provided in the service and installation bulletin accompanying each unit, - copies of which may be had upon request.

The following equipment is recommended as being extremely useful in conducting repairs on Mallory Elkon "B" Eliminators and Elkonodes:

1. High resistance volt-meter. Scale: 0 to 300. Resistance: Not less than 1000 ohms per volt,
2. One good quality milliammeter. Scale: 0 to 50.
3. One set feeler gauges.
4. One small screw-driver.
5. One pair thin, flat-nosed pliers (duck-bill type).
6. One 1932 Mallory - Elkon "B" Eliminator chassis.
7. One variable resistor- "dummy" load arrangement to duplicate maximum load for which each of six standard types of Elkonodes is designed.

Directions for Servicing 1933-34 Type Dual - Reed Mallory
' Self - Rectifying Elkonodes The 1933 Mallory Self - Rectifying Elkonode is a dual-reed converter which within itself sets up the essentially alternating current required, and likewise rectifies it to the form of direct current required for radio receiver plate supply. No rectifying tube is used with the 1933 Mallory Self - Rectifying Elkonode.

This Elkonode is supplied in five standard types- from in to 14 inclusive and modifications are supplied for special requirements under such designations as Nos. 30, 31, 34,35 (for Motorola Receivers), and Nos. 36 and 37.12 - volt types are supplied in types G10 to G14 inclusive, and 32 - volt types from F10 to F14 inclusive. The mechanical construction of the dual-reed Self - Rectifying Elkonode is the same in all types with the exception of size and number of turns of wire on Elkonode coil.

Page 2:

Following is a table of characteristics indicating output obtainable from each standard Elkonode at storage battery terminal voltage of
6.6, for the 6 - volt, 13.2 for 12 - volt type.
ELKONODE RATING TABLE

Current at which Phantom Load Relay should be adjusted

Special Types Should be Adjusted to SET MFRS. Specifications
(See Paragraph � � � N ") The following reproductions picture the Mallory dual-reed or self-rectifying Elkonode in two positions: (3) is a side view showing the Elkonode with cover and rubber cushion removed, and (4) is a front view with cover and cushion removed. Numbered arrows clearly indicate position of Elkonode parts involved in installing new contact spring and new reed assemblies.

Routine for Dismantling Dual - Reed or Self - Rectifying Elkonodes for the Purpose of Replacing Contact and Reed Springs

(a) Remove screws which fasten outer housing or can to base.

(b) Hold can in upright position and tamp gently against hand,
permitting base and rubber housing inside of can to drop out gently. (CAUTION: Do not attempt to remove Elkonode assemblies from cans by pulling on base.)

(c) Remove rubber cushion from Elkonode assembly in the same manner as entire assembly was removed from can.

(d) With internal assembly in view, displace.condensers by turning each outward from center carefully.

TO REMOVE SPRINGS AND REEDS: (e) Remove contact spring assembly by extracting screws at point marked "A" on above diagram, No. III,

(f) Remove reed assembly by extracting screws at point marked
"B" on above diagram No. III.

(g) Install reed assembly, using care to insure that metal brackets in which these recds are mounted are squarely aligned with reeds. (NB - Use only Kester Rosin Core Solder.)

(h) Install contact spring assembly using care to properly align metal brackets and blocks with which this assembly is mounted

(i) Inspect alignment of contact points to insure that contacts on reed and contacts on springs are in proper alignment. Their surfaces must engage squarely and evenly. Alignment of points is controlled by the position of the springs. Screws mounting these springs should not be tightened firmly until points are in alignment.

G) With points in proper alignment, air-gap or clearance between pole-piece of coil and counter-weights on ends of reed assemblies should be adjusted to approximately 1/32 inch, when reeds are pulled in to center position. This adjustment is provided for by removing or inserting shims between the Elkonode frame and coil, at top of coil.

(k) Loosen locking screw of stop posts (identified at point 3,
diagram III, above) so that tips of contact spring assembly engage screw-side of stop post head, allowing contacts to meet with contacts on reed assemblies at light pressure. Stop post is adjusted by turning to left until head of contact post pulls contact springs away from contact on reed assembly. Then turn stop post screw to right (about is to 1/4 turn) until contact points on both contact spring and reeds meet with light pressure. At this point, stop post locking screw should be firmly tightened to hold stop post in this position.

Page 3:

(1) It is extremely important, if secondary reed and contact spring assembly show any sign of having been burned as a result of " arcing, " that condenser No. 16611, rated at. 01 mfd. 1600 V., used across the secondary side of the Elkonode be replaced with a new one.

(m) Elkonodes which have become inoperative through the breaking down of this condenser, or which show evidence of over load at contact points, should never be replaced in Eliminators or automotive radio receivers until the adjustment of the'phantom load " relay has been checked carefully. Following is an outline of the causes which may bring about Elkonode failure through no fault of the Elkonode, and the method for correcting them:

(n) Elkonode failure is usually the result of a " no load " operating condition, which ordinarily is due to (A) film of dirt between contact points of phantom load relay. (B) iron filings between core and clapper of phantom load relay, (C) insufficient tension in phantom load relay springs, (D) open phantom load resistor, (E) receiver output tube defective. (F) connections to output tube open. Most prevalent of these difficulties are items (B) and (C) which invariably cause Elkonode failure through no fault of the Elkonode.

Conditions (A) and (B) are corrected by thorough cleaning with strips of paper. Condition (C) is corrected by inserting milliammeter in coil circuit of phantom load relay, or in B + lead to receiver, and adjusting spring tension so that relay clapper will pull to core when current is equivalent to current rating for that type of Elkonode, as indicated in foregoing table. Conditions (D) and (F) are detected by continuity checks, while Condition (E) is detected by means of a tube tester. (0) A choke coil is mounted within the rubber cushion in the base of the Elkonode can, and the continuity of this choke coil should be checked by continuity tests between mounting prongs and soldering terminal of the secondary contact spring assembly. (p) If the foregoing mechanical adjustments have been carefully followed out, the Elkonode is now ready for electrical tests. These tests should be conducted with a master Eliminator, into which the Elkonode can be inserted while the can and rubber cushion are still removed. A "dummy" load to equal the output characteristics of whichever type dual-reed self rectifying Elkonode is involved should be imposed, and all tests should be conducted with a battery terminal voltage of
6.6. Special types of Elkonodes designed for so-called " all electric " automotive receivers may best be tested in this same manner, or with a "dummy" resistor load to match the output characteristics of that Elkonode.

(g) Extreme care must be exercised to insure that no dirt or foreign matter is allowed to accumulate on contact points,
and that the entire Elkonode assembly is kept thoroughly dry. (r) "Excessive sparking " usually results from improper pressure between and alignment of contact points. If it is found necessary to bend reed assembly to secure flat alignment of points, this should be done by carefully grasping reed assembly at bracket where it is mounted with a pair of thin, flat-nosed pliers. A very slight pressure will be required to change the angle of contact for vibrator points. "No sparking " results from improper adjustment of stop post, permitting contact spring to follow reed spring past center of cycle of amplitude

or arc of vibration. Contacts should be lightly touching when at rest, so a clearance of approximately. 012 exists between stop post head and contact spring on interrupter side and. 002 to. 006 on rectifier side. Stop post will then break these contacts at center of cycle of amplitude. If the foregoing instructions are followed carefully, and if reliable instruments are used to measure output of Elkonodes when electrical adjustments are being completed, you should be able to install these contact spring and reed assemblies without difficulty. When adjustments have been completed to your satisfaction, place vibrator assembly inside rubber cushion by holding cushion in inverted position and allowing assembly to drop into place. Next, place entire assembly inside can, in the same manner, and fasten can to base.
Thorough instructions for servicing other parts of the Mallory - Elkon "B" Eliminator are provided in Service and Installation Bulletin accompanying each unit, copies of which may be had upon request. A circuit diagram of the entire Eliminator is shown herewith for your convenience in making continuity tests.

ARD KL ARE OMITTED It is important that Elkonodes be used only with Eliminators having same type numbers, and that phantom load relays and resistors are matched to type of Elkonode and Eliminator involved, Correct types of phantom load relays and resistors are shown in the parts list.

The following equipment is recommended as being extremely useful in conducting repairs on Mallory Elkon "B" Eliminators and Elkonodes:

1. High resistance volt-meter. Scale: 0 to 300. Resistance: Not less than 1000 ohms per volt.
2. One good quality milliammeter. Scale: 0 to 50.
3. One set feeler gauges.
4. One small screw-driver.
5. One pair thin, flat-nosed pliers (duck-bill type).
6. One 1933 type in Mallory - Elkon "B" Eliminator chassis, with one each proper phantom load relay and resistor for types 10, 11, 12,13 and 14. (A test-board switching arrangement to cut in which ever type phantom load relay is required for the Elkonode being repaired will be valuable in con ducting these tests.)