How close should a 4' Fluorescent bulb be to antenna before it lights?

[Jim WB5WPA]

Running 100 W, and having to be within 6" or so of the end before bulb will light up.

What is the usual experience with an 80 or 160 M antenna? Dipole or Vertical (this is a short vertical)?

I could be de-tuning the antenna too, come to think of it, approaching it with the bulb.
 

de Jim WB5WPA

[Opcom]

100W, 6" is OK, it will light farther away where the electric field is greater so you may wish to find that spot and use it for relative comparisons on what you are doing. You may be burned if you touch the pins and the power is great, and that will detune it. It won't load or detune until the lamp lights (assuming your body is not affecting it), so measuring the distance at which the lamp first lights is one way.

I tuned a powerful microwave transmitter and antenna in my back yard by standing 40W tubes in a row on axis before the horn and adjusting the stub section (plug) at the back of the antenna for more light from the farther ones. The sparks did fly.

Old CB artists used to do that all the time to check antenna workings. Small radios might light the whip at the tip, big radios would light it much farther down.