[Amps] Tank Circuit Problem.

[Mel]

An individual who does some transistor amplifier repair gave my friend a basket case mono-band sweep tube amplifier, it was missing tubes and, the circuit board under the antenna transfer relay was cooked beyond recognition.

I found a couple of 20LF6's and, I cut out the burned circuit board and hard wired the connections to the relay and the amp took off and started to put out power.

I know what this amp should put out, but this one does not; the first stage of the amplifier does not tune, there is no peak to the tuning.  

I am looking for ideas/troubleshooting tips.

With the original coil in the circuit, the amp has maximum output with the tuner fully meshed.  I piggybacked a 75 pf @ 5Kv doorknob and now, the amp puts out it's max at minimum capacity.  I changed the DC Blocking cap and, the RF choke is the stock 22 uh choke that came in the amp.

I started out with the original tank coil on the first stage (tuning gang was fully closed) and, I changed the tap on the coil up and down, with and without the external capacitance added and max DK was only about 150 watts.

Using the original coil as a model, I have wound 5 different coils of various lenghts that I substituted and tapped in an effort to get the watts up to an acceptable level.  I changed the circuit from a coil grounded and tapped to a coil straight between the two stages of the amplifier.

I cannot get this first stage to resonate and put out max power.  I by-passed the whole first stage and went into the five final tubes with 15 watts drive from my FT-101 and got more watts out than with the 2 drivers into the five finals.

Any suggestions would be appreciated.