How to inject a signal into a TV?

[ChrisW6ATV]

First, you need to have a device which can make different types of video, IF, and RF signals. A B&K 1077 or Sencore VA62 are good examples, and there are others as well.

The basic procedure, which is probably explained well in Milton Kiver's book, is to power up the set (with its own separate isolation transformer if it does not have a power transformer itself!), decide where you need/want to inject a signal, and then pick that signal type from the generator, which may have more than one set of output jacks/connectors. Typically, you use a cable or cables from the generator that have alligator clips on the ends. One clip (from the black or shield wire) goes to the chassis as a "ground", ideally near where you want to inject the signal, and another clip (from the red wire or the center wire of a coaxial cable) goes to your injection point. That point might be the grid pin of the video amplifier tube, or right after the video detector diode, for example. It is not an exact location, and it does not always have to be "just one right place per circuit". The one thing to avoid is connecting to the plate circuit of a tube (until you are using a device intended for that, such as a horizontal-output tester). Always put a voltmeter on the pin/connection you plan to use before you connect the generator. Then, adjust the generator while looking at the CRT or otherwise testing for the results you hope for.