When I feed twinlead, seems I might use a small fluorescent bulb to
show how it's doing.
....[snip]....

See:

"The Eyes Have It; Making S.W.R. Measurements with the Twin-Lamp"
on page 50 of the October, 1948, issue of QST.

"The 'Coax Twin-Lamp', A Simple S.W.R. Indicator for Solid Line"
on page 25 of the November, 1948, issue of QST.

"Measuring Center Impedance of Antennas with the 'Twin-Lamp" on
page 67 of the May, 1950, issue of QST.

"Old Reliable" on page 67 of the April, 1958, issue of CQ.

--W0PBV.

--
-- Myron A. Calhoun.
Five boxes preserve our freedoms: soap, ballot, witness, jury, and cartridge
NRA Life Member & Certified Instructor for Rifle, Pistol, & Home Firearm Safety
Also Certified Instructor for the Kansas Concealed-Carry Handgun (CCH) license