Zenith Color Roundie Alignment with B&K 415

[old_tv_nut]

Oh! Revelation! You are using the RF cable, 75/300 ohm switchable, which should only be used for antenna input. Use a plain unterminated cable as shown in the Zenith illustrations, with the RC network of figure 6.

[bhegges]

Originally Posted by old_tv_nut

Oh! Revelation! You are using the RF cable, 75/300 ohm switchable, which should only be used for antenna input. Use a plain unterminated cable as shown in the Zenith illustrations, with the RC network of figure 6.

I am using the Zenith service manual directions coupled with trying to use the B&K 415 and supplied signal cable which is the RF cable with built-in 75 or 300 ohm termination. There are no other signal cables described in their manual, see below. Also the snippet below had me believing I could the supplied cables and use the manufacture's directions, the output switch does have options to output video, IF, ch4, & ch 10, but it is odd to use a RF cable to feed into a IF circuit.




The Zenith service manual directions for the IF alignment steps in question state to connect the sweep and marker signals to the converter control grid (Test Point A on the tuner). No reference is made to any coupling circuit, which matches your note to use a plain unterminated cable. Zenith info below: