Phantom deluxe alignment

[John Chidgey]

Hello, 

Getting ready to do a Phantom Deluxe alignment.

Can someone help me identify the IF AVC LINE and the IF DIODE OUTPUT POINT?

Thanks

[Scott Seickel]

The IF AVC line comes from the 2nd detector diodes, goes thru a 1 meg isolation resistor, thru a 250k resistor, then thru those 3 position switches, thru the IF transformer secondary and to the grid of the IF tubes.  The AVC time constant is set by the capacitors off that line past the 1 meg resistor. 

[John Chidgey]

Thanks Scott

[David C. Poland]

There are two AVC circuits in a Phantom - identify the IF diode assembly and the RF diode assembly. Each required dismounting to replace a protruding cap to replace. 

You can identify the respective AVC line contact point with a VTVM probe - look for modest  negative voltage which will vary with a with a station tuning in and out with voltage from maybe 0 to negative -25 volts depending on station strength. 

[Alex R. Whitaker]

Pins 4 and 5 of the 6B8 3rd IF/2nd detector/IF AVC comes off of the diode plates.  I would imagine that to be the IF diode output point.   The IF AVC line runs to the grid of the 6G5 eye tube, and also to the secondaries of each IF transformer.  Get a highlighter marker and trace it out, and you'll see it.  It all starts at the diode plates of the 6B8 3rd IF/second detector.  

[John Chidgey]

Thanks for all of the great replies. All very helpful