"Anything's possible," but if the property owners use contracted management and they can't access roofs, I think they're crazy.

I'd be tempted to wait until 2 AM, lean a 40' extension ladder against the building, and just go up there myself.  What could they do?  Arrest you?

Probably "nothing," if they're too lazy to go up there, themselves.

I'm different, I guess: I think life's too short to be worried about somebody else's rules if what I do can't hurt anybody.

The other suggestion about parking a vehicle nearby and using a good mobile antenna is very good; I've done that, also, and it works a lot better than highly compromised "home" antennas.

Which log will it have?

Many log periodic beams include six meters, and even those that don't will often work on 6m a lot better than a dipole or a vertical will.

My Tennadyne T8 is not intended for 6m operation, but loads up well and is directional with a nice, clean pattern.  No way to measure what gain it has, but based on its characteristics, it has some.  I still have a separate 7L 6m beam (same tower, same mast) and the 6m beam is better; but the T8 works on six, better than a loop or vertical I can compare it to.

I'd try "valiantly" to get something above the roof.  Something low-profile that cannot be seen without flying over it in a helicopter, but something.

As for no ladder access, I'll bet there is and it can't be seen.  Or maybe something used temporarily for roof service, and then taken away; but there has to be some way to get up there, as air conditioning units, vents, chimneys and all sorts of stuff is likely up there.

I rented for 18 months a 3-story town house with stucco construction and a flat roof that was 40 feet above ground level.  Absolutely, positively no one could use any of the "common grounds" for anything not already in place and provided for residents, and that included roofs of course.

After a few months of cajoling the property management and homeowner's association, I ended up with two vertical, a 2m beam, a 6m beam, and a fan dipole for HF up there.   All the cables came down through an air vent and nothing could be seen from anywhere except overhead, or using binoculars from several blocks away.  That's the nice thing about flat roofs.

Biggest mistake I see is peaking PLATE and LOAD for maximum output power and then just leaving it like that.  With most amps, this is an underloaded condition and more LOADing will improve linearity.

With the AL-80B (and lots of other manually tuned tube amplifiers), I tune for max output then while observing grid current, I increase loading some more to reduce the Ig about 10%.  THEN, it's loaded.  IMD measurements confirm heavy loading produces cleaner signals, almost always.

UNDERloaded amps not only generate higher IMD, but often needlessly bang the grids when it's just not necessary.

It would be expired or invalidated today; however, it would be interesting to know what the registration number on that label is, so we could attempt to look it up.

Any FCC certification label should always carry the number on the label.

How do you know it's "FCC accepted?"

Today, an amplifier of any kind with those characteristics (frequency range, RF keyed, can be driven with 5W) cannot be certificated even if one stood on his head and juggled.

Does it have an FCC file number on a label or something?

You may find with a good manual tuner that you really don't have to touch it up much.  The AT may be re-tuning much more often than necessary.

Have you tried a manual tuner (even a borrowed one) just to see what happens?

That should be 50.100.

Yes, there's quite a bit of CW on 6m.  Mostly 50.080 to 50.100.  A lot of signals can fit in that space, and often do.

What happens if you terminate the cable in a well shielded 50 Ohm termination instead of an open or short-circuit?

You might contact Frank, W2IX.  He's in Carmel and has a tower and HF beam.

K2JO is also in Carmel with a substantial tower and beams.

Sounds like possible shipping damage.  I haven't experienced that, but anything's possible.

At least they're American-based and will cover such stuff under warranty, and from what I've heard, quickly.

Better still, to be assured you don't have such issues, buy a used one from a local ham selling one.   They've sold many, many thousands of these meters over the past two decades and they're always around.

This one is quite good: http://heilsound.com/amateur/products/proset/

I actually prefer a boom microphone and separate headphones, most of the time.  In my case, the reason is a "headset" doesn't allow you a lot of freedom to do things like eat or drink while operating (sometimes a contest necessity); you can push the mike up out of the way, but then you have to pull it back down to use it again.  With a boom mike I can just move back from the mike a few inches, then move in a bit closer to use it, without my hands having to adjust anything.

I'd recommend the Autek WM-1 over the others mentioned.

Autek is an American company with local service and I've owned WM-1s for many years with zero problems.  They work well for their cost point and are very easy to use.

The only other decent "true PEP" HF wattmeter in that price class is the Ameritron WM-30, which uses a cross-needle meter that I don't like as much; but electrically, it works well and about the same as the Autek.  A big advantage of the Autek is that its coupler is remote-able, connected by a cable, so you can hang the coupler where it's convenient for the cables and they don't try to pull the meter off your bench.  You can extend the cable and make it as long as you wish (use shielded cable) -- I made mine about six feet long, and that works fine.

Everything else is considerably more expensive, if you want a PEP instrument that has any sort of local warranty (or non-warranty) service available.

Daiwa doesn't. 

If the gutter downspout and tuner work on HF, they make work "better" on 6m, provided the tuner can find a match.

But stuff is more lossy on VHF.

A good approach might be to install a good mobile 6m antenna on your vehicle, park it outside, and run coax back to the "shack," hidden by bushes or whatever.  Then, if the band really opens up and gets exciting, you may be motivated to take the rig mobile, along with that antenna, find a high spot or a very "open" spot or someplace advantageous for VHF work, and just work it all from the mobile.

You'd have to install a hard-wired method of keying the relay.  The "key" jack is for a code key, not T-R keying.  You could re-wire that jack so it closes the coil connection to the T-R relay, and make that your "amp keying" line.

You'd also have to replace the input and output tank components, which are all set up for 10m (and 11m!) and won't cover 20m at all -- you need "bigger" parts to do that.  And you'd want to re-wire the "VFO" input jack to the cathode tank of the PA tubes so you can use a transmitter to directly drive the PA stage.  The way it's factory wired, if you transmit into the jack labeled "VFO," you're likely to blow up everything that follows that, since it's a low-level input.