(2) ADJUSTMENT OF LID MECHANISM
A spring mechanism is provided that balances the lid at any opening position. (See
frontispiece.) Failure of proper operation is indicated by the lid either continuing to
open or close after the hand is removed. If this condition is present adjust as follows :
(a) If the lid continues to open after being released, too much tension is present
on the spring. Reduce the tension by turning the adjusting screw counter-
clockwise gradually until normal operation is secured.
(b) If the lid closes upon release of the hand insufficient tension exists at the
spring. Increase the tension gradually by turning the adjusting screw clock-
wise until normal operation is secured.
If the spring has lost its tension it must be replaced. If a replacement spring is not
available try removing a turn from the old spring.
PART II-SERVICE DATA ON RADIO RECEIVER
The receiver assembly and S. P. U. of this receiver is very similar in both mechanical
and electrical characteristics to that used in Radiola 80. For service information on
these units other than that contained herein the reader is referred to the Service Notes
on Radiola 80. This includes :
Antenna system failures.
Radiotron sockets and prongs.
Noisy volume control.
Broken condenser drive cord.
Excessive hum.
Acoustic howl.
Low volume.
Distorted .reproduction.
Audio howl.
Oscillation.
Adjustment of R. F. line-up and oscilla or trimming condensers.
Adjustment of I.F. tuning condensers.
Line-up adjustments of gang condenser.
Dial scale reading incorrectly.
PART III-ELECTRICAL TESTS
The electrical tests given in RCA Radiola 80 Service Notes are all applicable to
the present instrument when the rotary switch is in the "radio reproduction" position.
There is one slight difference to remember, however, and that is the 1300-ohm choke
and .000745 mfd. condenser in the plate circuit of the 2nd detector in the present in-
strument that is not in the Radiola 80.
In addition to the tests already mentioned, special tests may be necessary on the
parts special to Radiola 86. These tests are included in the Service Data Sections (see
page 11, etc.) on these parts.
The receiver assembly and S. P. U. of Radiola 86 are exactly the same as those
used in the Radiola 82. The Radiola 82 Service Notes should be referred to when-
ever wiring diagrams are necessary for Radiola 86. Some models of Radiola 82 and
all models of Radiola 86 have a slight change in wiring from that shown in the dia-
gram of Radiola 82 receiver assembly, namely, the .025 mfd. condenser of the tone con-
trol connects to the positive plate supply instead of to ground. This change is made by
replacing the bus bar from the .025 mfd. condenser to ground as shown in the diagram
by a red lead from the condenser to the terminal strip to which five red leads are al-
ready attached. This is located on the under side of the chassis between the center
1. F. transformer and the chassis front.
10
www.americanradiohistory.com
