Model 61-R schematic

Yellow lead hot side of supply
Black lead ground side of supply

Socket layout
Alignment data
Vibrator date.

Receiver Alignment:

To align the I.F. circuit, an oscillator supplying 456 K.C. should be connected to the control grid of the 6A7 and the variable condenser frame. The grid cap normally on the 6A7 should be removed. The oscillator section of the variable condenser should be short circuited. This may be done by putting a small clip on the terminal of the oscillator condenser trimmer and running a wire to ground. It is preferable to use an output meter for accurate work, which may be connected into circuit of the 41 by means of an adapter having leads brought out from plate and screen through a 5 mfd stopping condenser. See Fig. #4.

The volume control on the receiver should be turned to maximum and the three I.F. adjusting screws shown in Fig. #2 set to give maximum on the output meter. This operation may be performed with the receiver in the can if a pair of long nose pliers or offset screw driver is used.

For R.F. alignment, remove oscillator condenser short circuit, replace grid cap on 6A7 and connect oscillator covering broadcast range to antenna wire and its shield.

Fig. 2:
37 first audio tube
Battery cable
Screws holding elmiminator
85 diode detector
Vibrator case
41 power tube
Second I.F. adjusting screw
Spring grounding vibrator case
84 rectifier for "B" supply
78 I.F. amplifier
Antenna coil
Oscillator section
R.F. section
Screws holding eliminator
6A7 oscillator detector
Antenna cable shield grounded to car

Vibrator Adjustment:
To examine vibrator, remove "B" supply unit from can by unsoldering 3 leads (see Fig. 3) removing 6 screws at ends of unit. Take cover off vibrator case and vibrator may be removed without unsoldering its lead wires. It will be seen that there are a top and a bottom set of contacts. The normal clearance on these contacts is .003" to .004" and this may be adjusted with screws provided.

Any dirt on contacts should be removed with pipe cleaner before adjustment. If top clearance is too great vibrator may operate but not close this circuit (operate half wave) and the voltage will be low. If bottom clearance is too great, vibrator will pull down but not vibrate. Too small a bottom clearance may short bottom contacts and cause in-operative vibrator and heavy current drain.

If both contact clearances are small, the vibrator will operate at a higher pitch and voltage, but sparking will occur.

Check of vibrator operation may be made by running three temporary jumpers from "B" supply unit outside can to the receiver, (See Fig. 3) and operating the vibrator outside its case so it is visible. The tone should be low pitched, even and regular, and no appreciable sparking should occur. To remove vibrator for replacement purposes, unsolder the three vibrator wires at the terminals of the step up transformer and at the ground terminal near the tube. Leads should be left attached to vibrator.

If set is not available or is in doubtful condition a 4000 ohm load resistance of 5 watts or larger may be used from plus "B" to ground of eliminator in place of set. The 6-volt supply is applied to the two terminals at the vibrator end of "B" unit.

If gaps are okay and sparking persists, check for dirty contacts or open condenser across primary of setup up transformer.

Fig 3a
Vibrator base is grounded to vibrator case
Vibrator cover is held by two end screws