Most people wouldn't notice if a few dB of loss come and go, unless it's
very abrupt. (And even then, it might not be noticed except under
unusual or very low-signal conditions.) Ionospheric conditions cause
much greater changes. Unless we have a solid reference antenna for
comparison, there's no way most of us would ever know if a few dB of
loss was coming and going. And, most people wouldn't care anyway.

When we pigeonhole antennas into the binary categories of "works" and
"doesn't work", there's a lot of room for slop in where the dividing
line is drawn.

Roy Lewallen, W7EL

Irv Finkleman wrote:
I once decided to try 300 ohm twinlead on my inverted Vee. I picked up
the cheapest stuff I could get from Radio Scrap and dropped it from the
vertex at about 50' down into the shack. It worked so well that it stayed
up for thirteen years.

I never cleaned it, and it went through all kinds of weather including
rain, freezing rain, snow, and at times was coated with hoarfrost. I never
noticed any degradation due to rain or snow.

I didn't do any measurements on it, and perhaps tweaked the tuner once
in a while, but in my opinion it was the best antenna I ever had (discounting
beams, mag loops, and verticals).

It went up in 83 and came down in 96 -- clean as a whistle, and was cut into
j-poles and other smaller antennas.

Anecdotal perhaps, for what it's worth...

Irv VE6BP

I still have a bit of it in my shop waiting for some future requirement.