[Drake] TR-4 question

[Jerry Kincade]

I have a new (to me) nice looking TR-4 on the bench, checking it out.
Haven't messed with Drakes for years, last one was an old beat up TR-3 years
ago, so I am looking for some advice. This one works gangbusters on 80 and
40, and receives fair on 20, 15, and 10. However, the finals won't load on
20 and above, with all three bands (20, 15,10) giving the same indication,
namely a nearly uncontrollable peak in plate current where there should be a
dip. Things seem normal as I key it and increase Transmit Gain slowly up
from idle current to get enough Ip to be able to see a dip (with PLATE and
LOAD controls at zero), but then Ip takes off out of control as soon as I
tune for a dip, with the Ip peaking at about the point on the plate tuning
where I would expect to see a dip instead. What really surprised me was the
Bird meter shows significant power out (80-100 watts) in consonance with the
unwanted Ip peak. This is no nickle-dime problem, Ip will jump to 600 mA
plus if I let it. Needless to say, I don't leave it long in that condition.
:-)

 Also, there is no definite noise peak on receive on the three problem bands
when using the RF TUNE control, although receive seems at least fair
(sensitivity seems a bit weak to me on 20 and above). 80 and 40 have clear
and definite noise peaks on receive using RF TUNE, with good sensitivity. My
first thought was improper neutralization, but per the book to neutralize it
you first have to tune up normally on 10, and that is not possible in this
instance. Besides, neutralization is intended to make max power and mininum
plate current occur at the same point, and that doesn't seem to be the
problem here. I'm thinking I have more wrong here than a simple
neutralization problem, and am wondering if maybe someone in the past has
attempted to "align" the transmit chain on 20-15-10, hosing things up.

I also may have a serious parasitic problem, but I fail to see why that
would occur in exactly the same way on three bands... ??

Next I will likely try the basic book alignment to see if anything has been
drastically mistweaked, but first wondered if anybody has any ideas. Finals
are new, and work great on 80 and 40, with smooth and clean peaks/dips and
it easily puts out 140-150 watts at 375-400 mA Ip on those bands, with clean
audio out on both USB and LSB.

Any ideas before I wander further into the woods with this thing? This TR-4
is not a junker, it's extremely clean inside and out, and appears to have
been well cared for. No mods are evident, and it does not appear to have
ever been subjected to a soldering iron.

Any sage advice from experienced Duck experts would be appreciated.

73, Jerry W5KP