Receivers aren't particularly fussy about antenna design.  If you are looking  for low angle or direction switching there is plenty of info on that, but by and large you will hear a LOT with  50 feet or more of  wire up and  in the clear.  Doesn't have to be a "brand", most of which are trying to make performance mountain claims about molehill differences-- like the plastic covered wire is quieter deal.  Make it a dipole, feed it with cheap twinlead, and match it with a used MFJ low power tuner.
What you need to study is what different lengths of wire do at different heights in terms of "arrival angle" and direction.  After a while, you'll be able to look at the doppleganger double zoomie 500 and say "Oh yeah, thats just an open wire fed double extended zepp." 

Why is it that Hiram,  who has spent all the equity in his home on  radio stuff  will work a rare station in a big pileup and tell the dx he is half a DB stronger than he was  yesterday, while the restof the radio  world waits. 

If some people didn't spend thousands working dx then perhaps the spoofers wouldn't enjoy themselves so much. 

I'd take a  100 feet of tower and turn it into a 4 square, then see what's what.

A number of us who DX a little remember the first signs of change in the old USSR, when home based ham operators  with up to date Japanese gear began to appear alongside the radio "klubs" "near Moscow" where it was "wx cold" using "15 tube radios" (and no doubt a "kommizar" sitting behind the guest op of the moment)  They used SSB and spoke such good english we suspected they might be KGB.
There was a time when the only  address for ANY Russian ham  station was "Box 88,  Moscow".  Things seem to be changing in the "worker's paradise" that is the Spanish minority dominated Cuba of today,   no doubt in part because so many more people are needed in the "technical arts".  I have heard the government "functionaries" now have access to lots of new Korean cars.

I only count my 80 meter dx, and I admire those guys dxing 160.

Google "Darby Hill Road, North Scituate, Rhode Island listening post"  for some real info.  Yes, tanks in North Africa could be heard.

PartsExpress.com

Not so long ago DD214s were a public record in Rhode Island town halls, and easily copied and "tuned up".  No longer,   one needs to show ID to get a copy of YOURS. 

The regulator end of a big Astron ought to be able to handle the problem.  Bypass the transformer and feed it directly. 

I've never liked the idea of joining ROUND wire by "compression". Not much surface area between the two conductors.  Every wire nut I have used in my home has been AFTER soldering the wires.  Belt and suspenders. 

Not sure what "signs of life" means.  Is the calibrator functioning?  You should see at least S 9 to 10 over on the lower bands with it on.  Sometimes a receiver which is working properly generates less nise than one with some failing parts.  Are all the voltages from the AC3 or AC4 correct within 10 % or so?

You might try another current balun in series with the antenna feedline.  Check the DX eEgineering catalog.  Good ones are not cheap. 

A pair of 3-500s with air system sockets and a stiff supply will do 1500 watts out "all day long"  without exceeding the published EIMAC ratings (which you could look up) .  The Al 1200 was sold before the "new" power regulations were imposed and it has a 1200 watt dissipation tube and a good, if loud, air system socket cooling system.  Many were uprated with Peter Dahl transformers.  THere are others which have good rf decks but marginal power supplies.
An L4 BASHER is a good amp and the outboard supply is easy to upgrade. Just doesn't do 160, as is also true of many Henry amps.  The SB 220, and the L7 have M. Mouse cooling systems,  and power supplies, as does the otherwise well made Kenwood TL 922, and the EIMAC specification for 3-500s used in non-airsystem sockets is to DERATE to 400 watts. 

Got any street lights stuck in the "start" mode?  One of the biggest noise generators these days seems to be pulse type battery chargers.