SX-71 2nd IF cathode resistor differences??!!
 

ON the Riders schematic V5 cathode resistor is (270 ohms V5 R22).
http://www.nostalgiaair.org/Resources/922/M0008922.htm

The radio chassis on the bench has a 1000 ohm.

The Sams on BAMA has 1000 ohm on the 2nd IF cathode (V6 R31).
http://bama.edebris.com/manuals/hallicra/sx71sams/

When (Run? or serial number?) was the change and why did they do it?

Thanks,

Paul P.