to NickZ & AG:

Thanks for your replies. For the old failed replication, I forget the exact frequency that the kacher/tesla and the push-pull are running at.  The push-pull runs at 11-17kHz. The tesla coil has many taps as can be seen from the pic. The highest frequency is around 1.2MHz with the antenna over the grenade connected. That might be too low to excite the grenade coil.

For the new replication, I decide to rewind both the tesla and the grenade windings since I have enough materials. Could you recommend the length [coil 'height', not the wire length] of the tesla coil to start with? I have 0.8mm enameled copper wire.
For the inductor coil, I happened to find a coil from the SR193 replication (which also failed), and the wire length is about 10.4m. I decided to unwind it and use it as the inductor coil on the grenade MAIN winding. That would fit into 2 layers. I want to make the inductor winding "thinner"， to make it easier for interaction.
For the ground, I live in a high-rise apartment, and am using the metal water pipe as the ground. I tried to use the EARTH from the AC socket, but it ends up triggering the fault protection breakers. In this case, how should I calculate the length of ground wire? Is that "L[ground]=L[water_pipe]+L[wire_from_the_water_pipe_to_the_device]" or simply "L[wire_from_the_water_pipe_to_the_device]"? I might simply use a short "L[wire_from_the_water_pipe_to_the_device]" to begin with.

will post further progress there.

PS: I do not understand the following picture "only unipolar pulses work here!". How is the pulses waveform measured? If one simply puts the scope probe around the tesla/kacher or antenna, one will see the waveform showed on the scope to be AC signal with no DC component because it's capacitive coupling. Also, what is the impedance transformer? Is it necessary?

Good to see this thread back on track. There's a coffee shop next door for anyone wanting a break from building. 
One observation from the Kapanadze green box videos is that the earth wire is taken through the centre tube of the grenade and connects to one leg of the load. The other leg of the load is connected to one end of the grenade winding. I do not see this in any of Ruslan's setups.

Ruslan connects his load before grenade which essentially is the same, and this indicates an in series resonance rlc. I work on a similar system and I see it. The lower the load resistance (which points to kw) the higher the current..

It might be important that the earth wire physically passes through the centre of the grenade, especially if he has ferrites in the tube. That is what I was getting at.

Hi guys long time

I have got nice link about good kapandze style replication

Please go through link

http://www.php66.com/hot/%E8%B6%85%E9%9F%B3%E9%80%9F%E7%81%AB%E7%84%B0%E5%A4%A9%E9%B9%85

http://list.youku.com/albumlist/show/id_27546084.html

Justawatt welcome again, and thanks for those links

Personally, I don't think his devices could be overunity. Also, there are not enough documentations about how to replicate his devices. We'd better focus on the ruslan/akula type of kapanadze device, and not to chase the wild "ultrasonic flame goose"  now.

Steadyfield, I guarantee you that the posted circuit has nothing to do with OU. The actual device which is presented, might be.  

Hi Jeg. From what I saw in the few videos I watched, he has just made a basic inverter circuit,
similar to the kinds of circuits Lasersaber used to make.

Yes and very inneficient to boot.

http://www.php66.com/player/XMzA4Nzg4OTY5Mg==

Guys, how can this be a normal inverter when he uses a welding maschine for at least half an hour? His input 12V bateries don't look big enough for this.