To certify the title is real, I do the following things
List the hardware:
First we have L2 then we make additional in order some main component:
C2; L1; C1; discharge wire that all for the resonance transformer of a DRSSTC.
There are all parameters:
L2= 1900turn s copper wire awg34; 3.5’ diameter ;15” long = 61mH (JavaTC)
C2= include 4 size’s 20cm; 25cm; 40cm; 50cm
L1=8turn flat spiral coil copper tube 1/4” 4.4 inner diameter 9.5’ outer diameter =
11.5uH (JavaTC)
Image 1 the coil.

Depend on the size of the toroid (C2 capacitance value) we can choose some size of the primary coil and capacitor tank. I think everybody want to choose the ratio L2/L1=C1/C2 as high as better. But practice show that higher 10000 (voltage gain factor=100)is not so good and lower 5000 of course not so good too. May be 7000-8000 is better. In this case this factor is about 5500 to save the low quality IBGT at low Apk I done a set of tests as follow:
Electrical control established and keeps them constant.
Halt bridge FGH60N60SMD low price China’s product.
Bus =320VDC.
Burst duration =100us.
Break per second= 200/s.
Image 2 several size toroid’s.

I replace the toroid step by step from small size to big size, tuning the coil until hit good tuning at every step, record the result on the notebook as follow:
After that i make double test set by reverse route to verify what was done.
Finally look at the information table and summary review:
First i saw the positive and reasonable signs between columns 2;3.
Last column give me a sudden contradiction.
Combine all information easily can answer the question in the title
140 kHz the best frequency for this coil with the conclusion “lowest consumption, highest power out”
One more special result I think need to report running at that point the frequency is very stability, from 20us to 140us burst duration it change very little, hard to recognize simply by looking the wave on oscilloscope.
I need to talk more about my L2 coil details
The copper enamel wire length of my coil is
1900*π*9=537.2m= λ/4
λ=2148.8m
F=300000/λ=139.6 kHz (this is frequency that the coil run at quarter length wave λ/4)
There was a coincidence of the results of the 1st line and quarter length wave law of the ." US Patent No. 645576, Nikola Tesla, System of transmission of electrical energy, filed September 2, 1897; granted March 20, 1900” from source The History of Tesla coil (Wikimedia)
To be honest, I did not expect this result. On the contrary, I was looking for intense sparks of toroid 40cm like DRSSTC2 3.5 "of laboratories Loneoceans because the results were impressive. This is only surprising, not heartbreaking.
Say something about RF alternating current.
Image 3 RF Alternating current in transmission line. (from Wikipedia English)

Let’s look at image3 and image4 they show that to obtain 1/4λ rule no need to fall into the correct position 25% of the wavelength, just stay in the area from the position 20% to 30% wavelength has been the perfect area.
For example the frequency matches 1/4λis 100 kHz that range will be 80 kHz to 120 kHz.
Image 4 RF Voltage/position of wavelength.

Of course I know what i wrote may be something isn’t true. So need to verify by other one.
Please let i say something about myself.
I am 69 year old, i play Teslacoil to find the spark as long as possible for fun 40% the rest i would like understand thorough and exactly how it work 60%.
In modern times the science side of Sir. Tesla's patent has not been confirmed or denied in the Teslacoil player community. That is DRSSTC is a quarter resonators or is not?
I look forward to invite 2 more enthusiastic coil man make the tests to verify this article true or fails. Need to make the tests on 2 different level of frequency, one at 200kHz and other at<100kHz.
Theoretically in knowledge resources about Tesla coil. We find the position of the resonant frequency point on the L2C2 reference point and then add the L1C1 reference point. We will get many results just like geometry positioning by 2 reference points if there is a 3rd projection we will immediately locate a single result quickly,λ/4is that point! So we can say that after finish wire winding a secondary coil we can know what frequency it will run better by the parameter “
The length of wire winding”
A short video clip (140us; 200b/s; 500w consumption; 2.5joules/bang) this result get after I have done a 5nd step: tape primary coil at 6.3turns (8.8uH) to increase primary current to 250Apk at 140us burst duration.
Many people succeed without caring about it because most normal models accidentally enter the green area very easily because this range is so wide or very badly enter the yellow zone so they still run. Only a few schools with incredible shapes will lot in the red and it will run very badly.
Quote:
Tesla was not the first to invent this circuit.[21][15] Henry Rowland built a spark-excited resonant transformer circuit (above) in 1889[2] and Elihu Thomson had experimented with similar circuits in 1890, including one which could produce 64 inch (1.6 m) sparks,[9][22][23] [1] and other sources confirm Tesla was not the first.[14][24][15] However he was the first to see practical applications for it and patent it. He even realized that the secondary coil functioned as a quarter-wave resonator; he specified the length of the wire in the secondary coil must be a quarter wavelength at the resonant frequency.[25][8]
I think if anybody can make a Tesla coil run at red range in this image. That job may be an affirmation that Tesla coil is not a quarter-wave resonator.
Dear forum admin board, if this topic has been reviewed initially, I request the administrator to invite 2 members directly to do the verification tests. To conclude the question of whether a 1/4 wave length has any role in DRSSTC.
Thank you so much.