COLLINS
30K, MODEL 1 AM TRANSMITTER (Serial #11)
& COLLINS 310A EXCITER UNIT (Serial #11)
PAGE
1 - PAGE 2 - PAGE 3
- PAGE 4
Pi-network to replace the original swinging link assembly.
It utilizes a
B&W 850A, R-175A RFC, and a couple of large variables. Unfortunately
the 850 did not do the trick due to the high plate load R of the 4-125A.
The 850A
was replaced by a ceramic bandswitch and a combination of B&W miniductor
and hand wound 3/16" copper coil. This is the test setup to determine
tap positions.
The resistor at bottom center represents the plate load resistance.
This view
shows temp alligator clips that are easily moved during testing.
Here is the final configuration; small 10-meter
coil; large coil for remaining bands
This view
shows the silver plated 10-meter coil, RFC on teflon form, tuning cap and
bandswitch.
Loading capacitor at bottom center and coaxial
antenna relay
