P.R. Mallory & Co. Dismatling Elknodes
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|Manufacturer:||P.R. Mallory & Co. (Elkon)|
Routine for Dismantling Elkonodes for the Purpose of Replacing Contact and Reed Springs
(a) Remove screws holding cover on can.
(b) Loosen cover from can and hold in upright position, prongs down; gently shake the rubber sock and Elkonode from the can.
(c) Closely observe the manner in which the leads from the prong base to the Elkonode are placed in the outer slots of the rubber sock. This is important for correct placement of wires when replacing assembly in can.
(d) Observe the location of the various parts, especially the position of the reed Armature (2) with respect to the coil pole shoe of the Elkonode. (1).
(e) Unsolder the three leads at the Elkonode terminals, noting that the top lead (with Elkonode held as in diagram) crosses over the ground lead to the center connection at the plug Unsolder the coil wire at the spring terminal.
(f) Loosen lock nuts A, and A2 and turn the adjusting screws B,
and B2 counter clockwise until the insulating bushings (5) are against the frame, then remove screws and slide out bushings.
(8) Loosen stack screws (3) and remove. Press on the under side of the bakelite stack and reed so as to move the assembly out from between the frame. Save the insulating bushings (5). stack screws (3), connector plate (4), adjusting screws, and the lock nuts. Remove the bakelite stack spacers and insulating tubes from the assembly.
ROUTINE FOR REBUILDING THE ELKONODE:
(h) Rebuild the stack assembly, making sure to use the thicker of the four bakelite spacers on either side of the reed.
(i) Since the Elkonode is largely magnetic in operation, extreme care must be taken to prevent particles or filings of iron from attaching themselves to the iron parts of the Elkonode. Clean the pole shoe, frame, and reed thoroughly.
6) Hold the assembly with the reed in the position shown in the illustration, place the frame under the assembly, as shown also, and insert the assembly from the top. It may be necessary to spread the frame slightly in order to make the insertion. Inspect the stack screws for signs of weakening, and if satisfactory, replace with the connector plate and tighten slightly.
(k) The reed should stand approximately in the center of the frame at rest. The end of the reed should be parallel to the face of the pole shoe and from. 003 " to. 005 " distant from it when the reed is pulled down opposite its center. This distance should be accurately set by feeler gauges. The reed may be adjusted because of play in the mounting holes.
(1) Insert the insulating bushings in the slots in the ends of the springs, thread the adjusting screws into place, together with the lock nuts. Adjust the screws to place the contacts close to the reed contacts. The springs should be moved so as to allow the contacts to strike the reed contacts without over lapping. The contacts should be fairly flat in making contact, and still not bind on the insulated adjusting bushing,
(m) Tighten the stack firmly without disturbing the adjustments.
Hold the reed over a piece of white paper in the vertical position shown in the illustration. The end edge of the recd, on the opposite side from the armature should rest from flush with the edge of the pole piece to. 003 " above same. Any bending of the reed should be done at the extreme armature end, and only slight alterations should ever be necessary. Should the pole shoe not be parallel with the armature in a vertical direction, turn the pole shoe with a pair of long-nosed. pliers; do not attempt to twist the reed. Check the air-gap spacing and tightness of coil mounting screws, if such adjustments are made, then recheck alignment.
(n) Solder the leads back as before, with the ungrounded heater terminal lead to the reed tail. The connector plate is soldered to the reed tail also, at the same time, and the coil wire to the near spring lug.
(o) Some method of exerting high pressure upon the stack end of the Elkonode while the final tightening of the clamping screws is taking place is essential. It is suggested that an arbor press, capable of exerting a total pressure of about 2000 pounds, be used. Pressure should be exerted directly over the stack, between the screws, while a large screw driver draws the screws down firmly. This prevents loosening of the stack in service and consequent failure.
(p) Turn the adjusting screw B - 1 clockwise until the space between the contacts G and H is between. 003 " and. 004 as measured carefully with a feeler gauge, with the lock nt A - 1 tightened firmly. Proceed likewise with B - 2 and A - 2 until clearance between contacts E and F is between. 004 " to. 006 ". Check lock nuts for tightness. The unit should then be ready for operation.
Following is a test circuit which may be set up for electrically testing and adjusting Elkonodes of the "50" Series. "Sound" tests may be obtained only with receiver in operation.
(q) If test equipment is available, operate the Elkonode on this equipment before placing it in the Elkonode can. The unit should start operation at
4.4 volts (2 cells of 6 - volt battery on charge), should provide correct output at
6.6 volts and should operate satisfactorily at
8.8 volts (4 cells on charge). Should any adjustment be necessary, adjust screw B - 2 only. A very slight movement of the screw should permit final adjustment.
(r) Do not attempt to bend contact springs.
Use only Kester Rosin Core Solder. Keep moisture from all parts of the Elkonode. Keep metallic particles out of Elkonode. Keep dust, moisture, grease and liquid from the contact surfaces. Clean contact surfaces with a dry, clean piece of linen paper.