I'm assuming your tuner isn't designed for such high power as to require water cooling?  

Did you disconnect the coax at the tuner and check?

The scary word in this instance is "used".  It might look pretty on the outside and be rusted all to bits on the inside.

Why use tubing?  At UHF, solid copper wire would likely stand up just as well as tubing and be a whole lot easier to bend. 

That SWR should read "2.5:1".

As for the tuner leaking, I have a suspicion: water intrusion into the coax and running downhill, as it will (thanks for inventing gravity, Mr. Newton!!  ).  Try disconnecting the coax and see if the connector is wet inside.  Similarly, rotor/rotator cable can serve as a nice water conduit if the high end isn't well-sealed.

Make sure the amplifier is unplugged and that the tubes have cooled down....

Mike I've seen RF mess up $500 Fluke DMMs, so the fact that a Home Depot cheapie reacts similarly is no shock.  That's why I use Simpson, Triplett and a few other varieties of regular, old-technology analog VOMs whenever a significant RF field is in the area where I'm trying to measure.  They're dang near bulletproof in these applications.

You can probably go even further back and get an Extra manual from the 1970s.  These don't have the question pool answers, but they do have a wealth of knowledge that should help you understand the material well enough to get those questions right.

The title of the thread is "The Wall" ... I suppose the Berlin Wall is acceptable!

We had a couple CTIs (Communications Technician - Interpreter) on the Kitty Hawk.  It was a common occurrence for the SecGru OInC to come into radio central and request my services.  Turned out I could copy Japanese Morse (wabun) better than either of the "pros". 

I worked and got a QSL from KG1AF in Thule, back in the early 1960s.

It's been tried, and the results have been largely disappointing, IMO.  Yes, you'd have to lay sections of the chicken wire fabric around the base, bonding section to section.  Since chicken wire is generally just galvanized steel wire, this means removing some of the galvanizing in order to get actual metal to metal contact, and preserving things once the bonding was complete.  When you say 50" (fifty inches), do you really mean 50' (fifty feet)?  It will make a bit of difference  .

Burying the chicken wire shouldn't be really necessary unless it'll be getting walked on.  However, chicken wire is lightweight stuff, and as a rule, if it's permanently in contact with typical soil it will disintegrate rather quickly.  Probably just hours before the DX contest you were going to kick tail in...

Perhaps, but you might  be surprised by how "Gitmo" is recognized by those of us who've been there.

Try using some close-fitting headphones to block out the other noise.

Using a straight key, you should be able to listen to the contacts closing and gauge from that how it sounds.  Granted, you're just getting started, but a correctly-sent letter will sound the same every time and FEEL the same as well.

Probably the worst insult you could give to a military operator:  ZBM2.  For those who might not have a copy of ACP-131 handy, that means "Place a competent operator on this circuit."

That's because what you call "water" is actually Dihydrogen Monoxide!!!

And neither watts nor volts describes a unit of current.