On Jun 2, 7:26*pm, Bob wrote:
Fire things up. For minimum SWR, the bulb nearest the transmitter will
be bright, the bulb nearest the antenna will be dark. Or if the two
bulbs are glowing with the same brilliance, you have high SWR.

I built one of those things in the 50's. I was feeding a resonant
1/2WL 40m with 1/2WL of TV twinlead. I could never get the reflected
bulb to go dim, no matter what I did, because 300/50 = an SWR of 6:1.
My reflected power was more than 1/2 of the forward power. It was only
four years later as I got close to a EE degree, that I understood why
the reflected bulb would never go dim. :-)
--
73, Cecil, w5dxp.com