OK, it appears you have the cap a little too high up the radiator, and yes, The DB did mention that the placement & value is critical!
On his model showing mast currents it appears to offer a near full half wave of constructive current, and that's why I thought 1/2 wave downward sloping radials in the guy line might help to radiate only that constructive 1/2 wave of current, while also fully decoupling & isolating it from the mast.
I hope that's not too cryptic, I'm excessively tired tonight.
And on your 36' model with sloping radials, here's my parameters one more time for clarity sake;
41 feet at feed point, not 36'.
Steeper sloping 108" wire radials than your model's 45°( I'll claim 67°) attached to the bottom Imax2000 U-bolt (recently I mistakenly told someone the top U-bolt).
...and - I'd like to see the difference (at 41' to the base) of both an isolated & a non-isolated Imax 2000, including 1/4 wave steeply downward sloping radials, and perhaps even 2 other models employing 1/2 wave steeply downward sloping radials.
I sure hope that doesn't sound like a demand, I'm just so whoop'd tonight, "I might be sending my wife's grocery list". - Red ROctober
Ideally, if I were to erect one tomorrow, from my anecdotal experience,
I'd go fully isolated with about 3'- 4' of schedule 40 gray PVC, over 1" solid fiberglass rod - leaving about 12" - 18" of it exposed between the top of the mast and the bottom of the Imax mounting plate - so I'd have a generous area for wrapping a 5.5 Turn x 4" diameter PVC former coaxial Common Mode Current Choke over that non-metallic part of the supporting mast structure.
Then I'd steeply slope four - six 108" guy wire radials downward at ~65° angle from the bottom Imax U-bolt, making sure to install it at ~41' at the top of the mast / Imax mounting plate.
...whew, that was draining.
I'm toast, 73
