A couple of suggestions:
it is not likely your 1:1 scope probe is going to cause high measurements. If it affects anything it may be responsible for your relatively low 20 meter reading although the 40/30/20 output filters start to roll off at 20 and this will account for some reduction. It is better to use a 10:1 probe as mentioned by others.
I have several RXTX and Peaberrys covering this frequency range and 10 MHz seems to be a sweet spot of the design. I have never seen 2.4 watts but several have been close to 2 for me so I do not question your numbers. At that power it is likely the 12V is pumping in 600-700 ma. I have a pile of BS170s but have never popped one, even at these power levels. Contrary to the observations of others they seem to be pretty rugged in this design, for me anyway.
I know of no practical way of equalizing the power output across the bands except backing off the IQ drive levels. And you probably will want to do this because at these high power levels the output stage gets very non-linear. I have found these stages go into severe compression at just under one watt normally. You can easily verify this - just back off the audio input by 3-6 dB and note the output power reduction. At the top end I find a 6 dB in audio drive only reduces the output by 2-3 dB. For CW and digital modes this is not a big issue but SSB is likely to sound pretty bad at the high drive levels.
Good luck and watch those fingers after a few seconds of 2.4 watts out!
Warren Allgyer - W8TOD
--- In email@example.com, "kh2br" <rholsti@...> wrote:
> I need some advice on how to equalize power output on my Ensemble RXTX built for 40, 30 and 20 meters.
> My power output is 7 Mhz--1.96 watts, 10 mhz-- 2.4 watts, 14 mhz .810 watts with out a external LPF filter connected to a 50 ohm dummy load
> and measured with a HP scope. Drive was set to max for these measurements and was using a 10 foot long 1:1 scope probe.
> Used very quick key down and lucky the finals did not pop on 10 mhz.
> Could the scope probe length throw off the readings?
> Bob KH2BR