I'm betting this will be an epic failure.? I'll put money on it.?
BBI, in his infinite wisdom, is documenting the....'worlds biggest 11m amplifier' on his U tube channel. Using the 4CW-100,000E water cooled tetrode.
Teaser video.? 7 mins long.? ? ??
Here is part #1.? ? ?It's? ?2 hrs and 27 mins long.? ? ?
I found 5 x mistakes so far.? ?This will be an epic failure.? ?It's? good entertainment though.
20 kw of drive for 500 KW? output.? ?Being built in Victoria Texas......in a welding shop.... by John? De Luna and BBI.? ?
Here is the detailed Eimac spec sheet for the 4CW-100,000E? ??
IF they are gonna run it in GG, with both screen and grid bonded to the chassis, the 500 watt grid will burn up 1st.
If it's gonna be grid driven, well have fun, esp neutralizing it.? ?If it's? gonna be cathode driven, like a Collins 30S1,? have more fun.? On the 30S1, the B+ supply, screen supply, and the bias supply are all in series, which means the screen and bias supply have max plate current flowing through em.?
I'm gonna assume 3 phase power to run it.? ?With 500 kw pep out,? it will suck? 800-900 kva.?
Well he did parallel 4 x 2 uf @ 40 kv oil caps for the B+ filter.? ?With 3 phase power, the raw DC from the 6 x leg rectifier assy has 5.2 % ripple.? ? With 8 uf of filtering and 20 kv,? total energy in the 4 x caps = 1600 joules = dick on a 770 kw? DC input supply.? Any hum will be? 360 hz. (6F on 3 phase).
The tube requires? 20 gallons per minute? at no more than 70 psi...... just for 100 kw CCS anode dissipation.? My garden hose only does? 4 gpm.? I would be worried about distilled water purity, and resistance, and possible super heated? steam explosions.?
100 kw of diss =? 341,000 BTU's? of heat to get rid of.? ?Do the maths, that will require one helluva BIG air cooled? and shrouded radiator to dump that much heat.?
Eimac also warns of an X-ray hazard, when operated > 15 kv.? ? ?The cavity needs to be lined with .020" lead sheeting.?
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?The folks? building this amp? are in for a rude awakening.? ? They are talking about 250 kw CXR, and swinging to 500 kw....and pep output close to a megawatt.? ?When tuned for close to a megawatt, the tank eff? with just the 250 kw CXR will be aprx 25%.? ? Anode diss = 750 kw.? ?Tube rated for 100 kw diss.??
Calculate the RF? current through the tank coil, and it's aprx? 225 amps.? Shit, even Kintronics doesn't make anything that big.? ?3" tubing would run hot.? ?The RF current through the tune and load caps is beyond horrendous.? ?205 amps through the load cap.? 102 amps through the tune cap.? 80 amps into the TR relay? + coax.? ?You would have to parallel 3 x Gigavac G52? spst vac relays to handle that current. 5.7 kv peak across the connectors, load cap, and TR relay...and coax....with a 1:1? swr.?
Toss in sundry items like the plate block cap assy, which will have? 100+ amps through it....... which in this case would have to be a fixed ceramic vac cap....and this will be end up being? the project of the decade.?
This amp would work....if they backed down on the insane power levels.? Dunno what they are gonna use for an ant,? but if it's a gamma matched yagi with a vac cap, they will be in for more surprises.? ?The rotor loop will be an? engineering feat in itself.? ?CM choke....good luck with that, not happening.?
IF they can pull it off, hats off to em.? IMO, they have bitten off more than they can chew.?
