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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.?
?
?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.?
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Freakn Crazy!?
Well, if anyone from that specific genre that coild seriously attempt and build such a beast, it would be Luke that could possibly? get away with it.
I wonder who has the.deep pockets to fund this folly??
I never thought of this guy as being any bit of a dummy. He always has seemed fairly smart and I have assumed that he had a good idea of what he is doing. Definately seems sincere and seems like he has enough smarts to understand and figure things out. But you really gotta question whay goes thru a guys head to do some crazy stuff like this and be all into that whole CB style of radio...?
It certainly seems as if there is a few decent talents rising from that crowd and so much more mamy of them aspiring to build stuff. I have found that there are few places on the internet that cater to big homebrewed RF amps without some of these guys being at the top of that game.?
There are some pretty crazy over the top worldwide dx contest stations. I suppose I am biased and can have a greater understanding for a multi-million dollar antenna farm and a bank of flagship contest gear quarter of million watt carrier single 11 meter band amplifier, i kinda just dont get it??
Do you think that BBI has just gotten too full of himself and is just talking a bit out the side of his neck?? Really two and a half hour video??
I will have to check this out. I can always ff thru parts of video. I believe he might actually start this project, will he complete it? I dunno? He must have a benefactor from Dubai or something of that sorts... pass the popcorn please.
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Maybe one should check the design of WLW back in the day w/500KW AM
.. and reportedly they had it up to 800KW just for fun.
Just observ'en.
Andy
On 3/8/2025 12:13 PM, Jim VE7RF via
groups.io wrote:
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.?
?
?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.?
--
"Where the Old Soo crossed the New Soo"
Duplainville, Wisconsin
Broadcastify Train Scanner:
Youtube Channel:
|
Looked at more of the BBI video.? He has done the fil choke wrong.? His method will saturate the type 43 cores.? ( no bifilar action).? ?The reason 2 x wires are passed through the core, or 2 x wires used on a rod is, that the current flows up one wire, through the cathode, then back down the other wire.? ?The 2 x magnetic fields cancel each other out..... resulting in zero? ferrite saturation.?
Also? saw where they modified the oem socket, and removed the screen bypass caps....which were originally above the chassis.? ? He has made of curved copper straps, so the former grid finger stock is bonded to the chassis.? ?Grid fingerstock sits on top of the copper straps.? Screen grid is also bonded to the chassis.?
IOW:? he's gonna try and run it as a high mu triode, with both the 1750 watt? rated screen grid.... and the 500 watt? rated? control grid, both bonded to the chassis........ no different than a 4-400? or? 4-1000? with both grids bonded to the chassis.? ?Problem is, the control grid in that config dissipates most of the power, with very little diss on the screen.? ?That's why the high mu triode version (3-500Z? / 3-1000Z) has double the grid diss...vs the tetrode.?
A 3x10/15/20? ?high mu triode has 500 watts of grid diss.? ? That's for? 15/25/30 kw pep out.? ?And typ 750 / 1250 / 1700 watts pep drive.?
Now? BBI wants to stuff 20 kw of drive into a tube that only has 500 watts of grid diss....... well good luck with that.? ?It requires a 3-6 kw? grid.?
Apparently, they are gonna? run the B+? supply on 240 vac? single phase.? ?Doable, but will require a 250 kva ccs xfmr out in the street, pad mounted....and a 1000++ amp rated drop wire.??
They are gonna find? all? this out the hard way.?
|
I suspect this project will only end with embarrassment for all parties involved.
I do not watch the videos this person publishes. I watch and read only what I know to be correct, With the intent to learn.
Sad thing is there are so many people that think anything they see online is correct.
I just pray no harm is done to anyone or anyone’s property from this mess.
I only know of it from what Jim has told me.
4 minutes of my life wasted.
toggle quoted message
Show quoted text
On 2025-03-11 12:31, Jim VE7RF via groups.io wrote: Looked at more of the BBI video. He has done the fil choke wrong.
His method will saturate the type 43 cores. ( no bifilar action).
The reason 2 x wires are passed through the core, or 2 x wires used on
a rod is, that the current flows up one wire, through the cathode,
then back down the other wire. The 2 x magnetic fields cancel each
other out..... resulting in zero ferrite saturation.
Also saw where they modified the oem socket, and removed the screen
bypass caps....which were originally above the chassis. He has made
of curved copper straps, so the former grid finger stock is bonded to
the chassis. Grid fingerstock sits on top of the copper straps.
Screen grid is also bonded to the chassis.
IOW: he's gonna try and run it as a high mu triode, with both the
1750 watt rated screen grid.... and the 500 watt rated control
grid, both bonded to the chassis........ no different than a 4-400 or
4-1000 with both grids bonded to the chassis. Problem is, the
control grid in that config dissipates most of the power, with very
little diss on the screen. That's why the high mu triode version
(3-500Z / 3-1000Z) has double the grid diss...vs the tetrode.
A 3x10/15/20 high mu triode has 500 watts of grid diss. That's
for 15/25/30 kw pep out. And typ 750 / 1250 / 1700 watts pep drive.
Now BBI wants to stuff 20 kw of drive into a tube that only has 500
watts of grid diss....... well good luck with that. It requires a
3-6 kw grid.
Apparently, they are gonna run the B+ supply on 240 vac single
phase. Doable, but will require a 250 kva ccs xfmr out in the
street, pad mounted....and a 1000++ amp rated drop wire.
They are gonna find all this out the hard way.
Links:
------
[1] /g/ham-amplifiers/message/41063
[2] /mt/111589618/8135091
[3] /g/ham-amplifiers/post
[4] /g/ham-amplifiers/editsub/8135091
[5] /g/ham-amplifiers/leave/12941173/8135091/773995006/xyzzy
|
Apparently, they are gonna? run the B+ supply on 240 vac? single
phase.?? Doable, but will require a 250 kva ccs xfmr out in the
street, pad mounted....and a 1000++ amp rated drop wire.
BBI: "I'm gonna need my goo drop resized to a bunch of 4-ought wires." Electric Company: "Just how acres is yer grow house gonna be??" He's gonna need his own cooling lake, too. Is this guy one of those uber-rich Texas billionaires that's working on those ultra-miniature fusion nuclear reactors? Rather than watch his videos, I'll save my limited time left on this mortal coil to something more productive, like "I Love Lucy" or Abbott & Costello reruns.
|
One or more of the readers herein have constructed linear amplifiers
capable of more than the two kilowatts input our tickets say is kosher
for the ham bands.
?
We do so in order to solve a problem with the math, (like the
160 meter issue in the Alpha 77-Sx), or with the power plant
design questions, (such as in the Henry 8K Ultra with the
resonant choke dilemma), etc.
?
One thing I discovered is that the fundamental hurdle for me
has always been The Budget. I’ve got most of the bits sitting
in the Parts shed to start in on a 4CPX5,000A amplifier, but
as I grew older I saw that sinking money into another big
Tetrode is not going to get me anywhere but poorer, and to
think about where Ham Radio has gone recently, spending
the Big Bucks on another amp build just doesn’t seem
to be as fruitful as it used to, in days gone by.
?
The bits and pieces to slam together another crusty amplifier
are not as plentiful, and when they are found, the prices for
them are not as cheap as they once were, even on the
surplus distribution channel.
?
Remember Fair Radio in Lima, Ohio? At one time a builder
could find some top-notch pieces, but as time went by,
the drawers and bins held less and less, until the sales
there didn’t keep the lights lit.
?
Even things like electrolytic or oil-filled filter capacitors
are hard to locate any more, and if you want to build
some big iron, you need to get that HV A.C. into the
D.C. world, and there are some budget hurdles
just in that little corner.
?
When the kids from the U/Mo radio club came out to pick
up most of everything from the “big station,” here, they
looked at the tons of components, and their “big” question
was “What do we do with all that?”? “All that,” is not enough,
any more. Ask most any one who continues to build.
?
Hal Mandel
W4HBM
?
|
I think Luke and John will get it working before
SpaceX arrives on Mars, both projects have the
potential to make a big BOOM!
?
Here's a theoretical design using a 4CX3000A as a driver:
?
?
Redesigned 100KW PEP 11M AM/SSB Amplifier
1. Block Diagram
-
Exciter: Yaesu FT-101E transceiver (27 MHz, 11-meter band).
-
Intermediate Amplifier: 4CX3000A tetrode amplifying the FT-101E output to drive the 4CW-100,000E.
-
Final Amplifier: 4CW-100,000E tetrode delivering high-power output.
-
Power Supply: High-voltage supplies for both tubes, plus filament and bias.
-
Output Network: Matches the 4CW-100,000E output to a 50-ohm antenna.
-
Cooling: Forced air for the 4CX3000A, water cooling for the 4CW-100,000E.
2. Operating Modes
Component Details
Exciter: Yaesu FT-101E
-
Output Power:
-
Frequency: 27 MHz (11-meter band; assumes modification or original CB capability).
-
Output Impedance: 50 ohms.
-
Modulation: Built-in AM/SSB modulator.
Intermediate Stage: 4CX3000A
The 4CX3000A is a forced-air-cooled tetrode with substantial power capacity, often used in broadcast and industrial applications.
-
Maximum Plate Dissipation: 3,000 W.
-
Plate Voltage: 4–6 kV (typical operating range).
-
Output Power:
-
AM: ~2,000–2,500 W carrier, ~8,000–10,000 W PEP (Class B, 60-70% efficiency).
-
SSB: ~3,000–4,000 W PEP (Class AB1, linear mode).
-
Gain: ~13-15 dB (20-30x power gain).
-
Input Power Required:
-
For 2,000 W output: ~80-100 W (matches FT-101E AM/SSB output).
-
For 3,000–4,000 W PEP: ~120-200 W (slightly above FT-101E SSB output; assumes slight overdrive or additional preamp).
-
Cooling: Forced air (~200-300 CFM, per Eimac specs).
-
Matching: Pi-network to transition from 50 ohms (FT-101E) to the 4CW-100,000E grid impedance.
Design Notes:
-
Operate in Class B for AM efficiency or Class AB1 for SSB linearity.
-
Plate voltage: 5 kV, ~600-800 mA plate current.
-
Screen voltage: 500-700 V.
Final Amplifier: 4CW-100,000E
-
Plate Voltage: 15 kV (conservative, below 20 kV max).
-
Plate Dissipation: 100 kW max (targeting 50-70% of capacity for reliability).
-
Gain: ~15-20 dB (30-100x power gain, depending on conditions).
-
Input Power Required:
-
Cooling: Water-cooled, 20-30 GPM.
Modulation:
Power Supply:
Output Network:
-
Pi-network or tank circuit to match the 4CW-100,000E’s high-impedance output to a 50-ohm antenna.
-
Components: High-voltage capacitors (500 pF, 20 kV) and inductors (~1-2 ?H).
Power Output Forecast
Assumptions:
-
Efficiency:
-
4CX3000A: 60% (Class B, AM), 50% (Class AB1, SSB).
-
4CW-100,000E: 70% (Class C, AM carrier), 60% (Class AB, SSB).
-
Gain:
-
4CX3000A: 14 dB (25x, midpoint of 13-15 dB range).
-
4CW-100,000E: 17 dB (50x, midpoint of 15-20 dB range).
-
Modulation: AM uses plate modulation on the final stage; SSB is linear amplification.
AM Mode:
AM Output:
SSB Mode:
SSB Output:
Final Specifications
-
Frequency: 27 MHz (11-meter band).
-
Power Output:
-
AM: 70 kW RMS (carrier), 280 kW PEP.
-
SSB: 25 kW RMS (average), 100 kW PEP.
-
Exciter: Yaesu FT-101E (50 W AM carrier, 100 W SSB PEP).
-
Intermediate Stage: 4CX3000A (~2,000 W AM carrier, 3,000 W SSB PEP).
-
Final Stage: 4CW-100,000E (70 kW AM carrier, 100 kW SSB PEP).
-
Cooling: Forced air (4CX3000A, 200-300 CFM), water (4CW-100,000E, 20-30 GPM).
-
Power Supply: Multi-voltage (5 kV for 4CX3000A, 15 kV for 4CW-100,000E).
Comparison to a 4CX1500B Driver Design
Practical Notes
-
Tuning: Precise matching networks are critical for stability, especially with the higher drive levels.
-
Linearity: The 4CX3000A in Class AB1 ensures good SSB performance; AM uses Class B in the intermediate stage and Class C in the final stage with plate modulation.
-
Legality: 70 kW AM or 100 kW SSB far exceeds 11-meter limits (4 W AM, 12 W PEP SSB in the U.S.). This is for experimental or licensed high-power use only.
-
Tube Limits: The 4CW-100,000E is pushed near its 100 kW dissipation limit in AM mode (70 kW carrier + modulation peaks); ensure adequate cooling and duty cycle management.
-
Verification: Exact output depends on tuning, tube condition, and drive—consult data sheets for precision.
|
Hey Scott - I watched bits of the video. I saw the plan to power the plate TX with 240V !! Jeez…..!
I, like you, enjoyed Jim’s points of issue.
John VK6JX
P.S my YC156 amp is going great guns on 160 and 80m. What a great tube.
toggle quoted message
Show quoted text
On 12 Mar 2025, at 3:03?am, Amp Guy Llc via groups.io <kb1sel@...> wrote:
?I suspect this project will only end with embarrassment for all parties involved.
I do not watch the videos this person publishes. I watch and read only what I know to be correct, With the intent to learn.
Sad thing is there are so many people that think anything they see online is correct.
I just pray no harm is done to anyone or anyone’s property from this mess.
I only know of it from what Jim has told me.
4 minutes of my life wasted.
On 2025-03-11 12:31, Jim VE7RF via groups.io wrote:
Looked at more of the BBI video. He has done the fil choke wrong.
His method will saturate the type 43 cores. ( no bifilar action).
The reason 2 x wires are passed through the core, or 2 x wires used on
a rod is, that the current flows up one wire, through the cathode,
then back down the other wire. The 2 x magnetic fields cancel each
other out..... resulting in zero ferrite saturation.
Also saw where they modified the oem socket, and removed the screen
bypass caps....which were originally above the chassis. He has made
of curved copper straps, so the former grid finger stock is bonded to
the chassis. Grid fingerstock sits on top of the copper straps.
Screen grid is also bonded to the chassis.
IOW: he's gonna try and run it as a high mu triode, with both the
1750 watt rated screen grid.... and the 500 watt rated control
grid, both bonded to the chassis........ no different than a 4-400 or
4-1000 with both grids bonded to the chassis. Problem is, the
control grid in that config dissipates most of the power, with very
little diss on the screen. That's why the high mu triode version
(3-500Z / 3-1000Z) has double the grid diss...vs the tetrode.
A 3x10/15/20 high mu triode has 500 watts of grid diss. That's
for 15/25/30 kw pep out. And typ 750 / 1250 / 1700 watts pep drive.
Now BBI wants to stuff 20 kw of drive into a tube that only has 500
watts of grid diss....... well good luck with that. It requires a
3-6 kw grid.
Apparently, they are gonna run the B+ supply on 240 vac single
phase. Doable, but will require a 250 kva ccs xfmr out in the
street, pad mounted....and a 1000++ amp rated drop wire.
They are gonna find all this out the hard way.
Links:
------
[1] /g/ham-amplifiers/message/41063
[2] /mt/111589618/8135091
[3] /g/ham-amplifiers/post
[4] /g/ham-amplifiers/editsub/8135091
[5] /g/ham-amplifiers/leave/12941173/8135091/773995006/xyzzy
|
It appears they have already? been notified that their proposed? cathode driven config...with both screen and grid bonded to the chassis? is fubar, and the poor control grid will vaporize....with 20 kw pep of drive into the 500 watt rated grid.? ?It wouldn't work anyway, their fil choke is a total write off.?
Dunno where? BBI? got this idea that he needed a 4CX-15,000? as a 1400 vdc? screen regulator.? ?A simple? FWB +? resonant choke, and bleeder would easily suffice...and have superb regulation.?
Dunno if they will take the kind advice of some fellow? 11m? builders who explained? this all? to? De Luna + BBI.? ?The other builders have succesfully built grid driven 4CX-5000 amps, complete with screen and bias supplies, then terminated the grid with a grid loading resistor.? ?So far, they have not responded.?
If they do, they? will have to rebuild the $4K? socket...and replace all the screen bypass caps? and unground both the screen and control grid.?
If they don't take the sage advice,? they can kiss the control grid goodbye.?
|
When bolting-up the tube sockets for the GU-84b’s
I could tell they were some doozies.
?
Cleaning the silver metal without removing
it from plated instead of solid metal contact
areas required a toothbrush and a pile or two
of Kool-Amp silver plating powder to get the
‘low hanging fruit’ acceptable.
?
The big surprise for me were these green glazed
oblong-shaped capacitors with silver metal flat
contacts on each end. They formed a circle around
one of the concentric parts of the sockets.
?
?
The grid port, going back through the neutralizing Breuhne bridge
is bypassed, or perhaps better named as “loaded” with a non-inductive
450 ohm, 50 watt 1% resistor that can easily be replaced
or removed as the neutralizing process is analyzed on the bench.
?
With the cost of all these little specialized pieces taking longer to
agree with myself that the purchase will probably be useful has
gauged my efforts in getting this project ‘hot’ and making satellite
contacts on 10m.
?
This is why, looking at the 500MW nuclear reactor experiment
elsewhere, I wonder who performed the calculations for each
and every component, and how did the design choice fare on
a peer review for viability, feasibility and reasonability?
?
Hal
W4HBM
?
|
They don’t calculate , they use the trial and error method.
They think it’s normal to loose a doorknob cap, vacuum variable capacitor, tube etc. Swap part with the next size up and repeat.
toggle quoted message
Show quoted text
On 2025-03-12 10:28, HaL Mandel via groups.io wrote: When bolting-up the tube sockets for the GU-84b's
I could tell they were some doozies.
Cleaning the silver metal without removing
it from plated instead of solid metal contact
areas required a toothbrush and a pile or two
of Kool-Amp silver plating powder to get the
'low hanging fruit' acceptable.
The big surprise for me were these green glazed
oblong-shaped capacitors with silver metal flat
contacts on each end. They formed a circle around
one of the concentric parts of the sockets.
The grid port, going back through the neutralizing Breuhne bridge
is bypassed, or perhaps better named as "loaded" with a non-inductive
450 ohm, 50 watt 1% resistor that can easily be replaced
or removed as the neutralizing process is analyzed on the bench.
With the cost of all these little specialized pieces taking longer to
agree with myself that the purchase will probably be useful has
gauged my efforts in getting this project 'hot' and making satellite
contacts on 10m.
This is why, looking at the 500MW nuclear reactor experiment
elsewhere, I wonder who performed the calculations for each
and every component, and how did the design choice fare on
a peer review for viability, feasibility and reasonability?
Hal
W4HBM
Links:
------
[1] /g/ham-amplifiers/message/41070
[2] /mt/111589618/8135091
[3] /g/ham-amplifiers/post
[4] /g/ham-amplifiers/editsub/8135091
[5] /g/ham-amplifiers/leave/12941173/8135091/773995006/xyzzy
|
If they grid drive it...... that tube has a whopping 370 pf of input C.?
|
This is the best entertainment yet on this group!
In a previous post there were a set of specs that indicated "plate modulation" of the final running Class C and an audio requirement of 70KW! No details on that. That in itself is a major undertaking, including where to find a mod transformer! Then how to T-R this whole set up.
I also saw that they intended to use glycol treated water for cooling! THAT will not work. Distilled water with resistance monitoring is required. Been there before on a commercial project that eventually abandoned water cooling. Too many maintenance issues. A bunch of amateurs will NOT figure this out.
Yeah...entertaining....I suspect at some point it all will go away when either it blows up (100%) or they figure out it's hopeless design.
If those CB'ers want a big signal, then I suggest for a fraction of the cost of this amp, an antenna system would be FAR better for those additional db's.
-Chuck K1KW
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-----Original Message----- From: [email protected] [mailto: [email protected]] On Behalf Of Amp Guy Llc Sent: Wednesday, March 12, 2025 2:36 PM To: [email protected]Subject: Re: [ham-amplifiers] Total insanity....500KW 11m amp being built. They don’t calculate , they use the trial and error method. They think it’s normal to loose a doorknob cap, vacuum variable capacitor, tube etc. Swap part with the next size up and repeat. On 2025-03-12 10:28, HaL Mandel via groups.io wrote: When bolting-up the tube sockets for the GU-84b's
I could tell they were some doozies.
Cleaning the silver metal without removing
it from plated instead of solid metal contact
areas required a toothbrush and a pile or two
of Kool-Amp silver plating powder to get the
'low hanging fruit' acceptable.
The big surprise for me were these green glazed
oblong-shaped capacitors with silver metal flat
contacts on each end. They formed a circle around
one of the concentric parts of the sockets.
The grid port, going back through the neutralizing Breuhne bridge
is bypassed, or perhaps better named as "loaded" with a non-inductive
450 ohm, 50 watt 1% resistor that can easily be replaced
or removed as the neutralizing process is analyzed on the bench.
With the cost of all these little specialized pieces taking longer to
agree with myself that the purchase will probably be useful has
gauged my efforts in getting this project 'hot' and making satellite
contacts on 10m.
This is why, looking at the 500MW nuclear reactor experiment
elsewhere, I wonder who performed the calculations for each
and every component, and how did the design choice fare on
a peer review for viability, feasibility and reasonability?
Hal
W4HBM
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Correct.? They use trial and error.? They have no clue how much? RF current is flowing through any component.? ? They just.....'pile drive'? the crap out of anything and everything...then wonder why the tube doesn't last.? Ditto with parts.? They overheat and blow up, or peak V? arcs something.? ?The last goofy one I saw on De luna's? fb page.... was where a fellow used magnet wire for the coil on the tuned input, fine..... but he had a mile long magnet wire...going to the cathode of the gg triode.?
Mike,? good detailed description.? ? Problem is..... typ 11m op wouldn't have a clue how to plate modulate anything.?
Why mess with AM is beyond me....esp when using a linear amp? in AM mode.? ?As I have shown before,? SSB has a 12.04 db? advantage over AM.?
EG:? ?CXR? is? 6 kw........swings to 9 kw.? Pep out is 24 kw.? ?When it swings from 6 - 9 kw, that's? 3 kw of total sideband power...with just 1.5 kw into each sideband.? ?You could get 1.5 kw into one sideband with a 8877.
Same tube, with 24 kw pep out on ssb.? ?24 kw / 1.5 kw =? 12.04 db.? ?This is why linear AM? is? such a wasted effort.?
IF I was a hardcore? 11 m op....... I would put up? 2-3-4? stacked yagi's....and clean house.? ?Then worry abt the amp.....and also deep six? AM mode.??
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May be the end of the channel owner. Utter failure might be a hard thing to recover from. Seeing as though on the world stage .
Perhaps people will finally see there is no true knowledge , all smoke and mirrors.
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On 2025-03-12 15:50, Jim VE7RF via groups.io wrote: Correct. They use trial and error. They have no clue how much RF
current is flowing through any component. They just.....'pile
drive' the crap out of anything and everything...then wonder why the
tube doesn't last. Ditto with parts. They overheat and blow up, or
peak V arcs something. The last goofy one I saw on De luna's fb
page.... was where a fellow used magnet wire for the coil on the tuned
input, fine..... but he had a mile long magnet wire...going to the
cathode of the gg triode.
Mike, good detailed description. Problem is..... typ 11m op
wouldn't have a clue how to plate modulate anything.
Why mess with AM is beyond me....esp when using a linear amp in AM
mode. As I have shown before, SSB has a 12.04 db advantage over
AM.
EG: CXR is 6 kw........swings to 9 kw. Pep out is 24 kw. When
it swings from 6 - 9 kw, that's 3 kw of total sideband power...with
just 1.5 kw into each sideband. You could get 1.5 kw into one
sideband with a 8877.
Same tube, with 24 kw pep out on ssb. 24 kw / 1.5 kw = 12.04 db.
This is why linear AM is such a wasted effort.
IF I was a hardcore 11 m op....... I would put up 2-3-4 stacked
yagi's....and clean house. Then worry abt the amp.....and also deep
six AM mode.
Links:
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[1] /g/ham-amplifiers/message/41074
[2] /mt/111589618/8135091
[3] /g/ham-amplifiers/post
[4] /g/ham-amplifiers/editsub/8135091
[5] /g/ham-amplifiers/leave/12941173/8135091/773995006/xyzzy
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In VO stokes book, they avoid water cooling and vapour phase cooling like the plague.? ?U can't use glycol mixed with distilled water. That combo will eat the inside of the tube.? Reason it has been used in the past for commercial broadcast is? if the commercial AC power went out at a remote site in winter...say a hill top, the water would freeze..... resulting in busted water lines, tube, pumps, radiator etc.?
Notice on asamoto's ASI site, he loops the water line inboard on the 1st loop, then the 2nd loop touches the RF deck sidewall....then it's off to the rear wall? water fitting.? ?That's done for a reason, to get max distance on the waterline...b4 it touches any metal.?
Water purity and filtering has to be done....along with resistivity.?
?
20 GPM at high pressure is no mean feat.? ?My garden hose is 4 gpm.?
I still want to see the proposed? tank coil.?
This is not an amp, you want to document on u tube..... with several flaws in the....'design'....then make urself look silly.? ?It's not engineered at all, it's ill conceived.?
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Anytime a radiator is initially filled, like in a car, it's? typ? vac filled.? ?The last thing you want is trapped air? anywhere in the loop.? ?That would be a disaster on a 100 kw water cooled tube.? ?I'm assuming the large air cooled radiator will be outside the shop, ( to dump the heat to the outside)..... so lengthy water lines? will be involved.? IE: the total loop distance has increased.?
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Mike, where are they gonna obtain a modulation xfmr ??? ? Per the? Eimac spec sheet for plate modulated AM,? ?the secondary of the modulation xfmr would have? 15 kvdc across it...and 23.4 amps? flowing through the sec of the modulation xfmr.? ?The 15 kv across the modulation xfmr will rvs in polarity.....and the sec of the mod xfmr is in series with the 15 kv? B+.? ? And that's just for 100%? positive modulation.
IE:? the B+ would? swing to? +30 kv? on positive mod peaks..... and down to 0 volts? on negative peaks.?
15 kv? @ 11.7 amps = 175.5 kw modulation xfmr.? ?At the crest of the positive modulation,? B+ on the anode? is now? 30 kv....and plate current is now double at 23.4 amps.?
Let's assume plate modulation is not happening any time soon.?
They shoulda just run it grid driven, for linear service? like on the spec sheet.? ?200 kw pep out, and 50 kw cxr......which? swings to 75 kw.? ?That's 25 kw of total swing....( 25 kw of? total sideband power)..., with just 12.5 kw into each sideband.?
Still a wasted effort.? The 3x6 amp puts out 12.5 kw pep on ssb.?
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Hi Jim,
Your're exactly right!?? i agree, the Only way is grid drive.?? Thanks for taking time do the math and and expose the massive plate? current on peaks.
Regardless, it's a crazy project but we are getting to exercise our imagination and exploring the limits of big steel tubes.
73's, Mike?
VK6ADA
Mike, where are they gonna obtain a modulation xfmr ??? ? Per the? Eimac spec sheet for plate modulated AM,? ?the secondary of the modulation xfmr would have? 15 kvdc across it...and 23.4 amps? flowing through the sec of the modulation xfmr.? ?The 15 kv across the modulation xfmr will rvs in polarity.....and the sec of the mod xfmr is in series with the 15 kv? B+.? ? And that's just for 100%? positive modulation.
IE:? the B+ would? swing to? +30 kv? on positive mod peaks..... and down to 0 volts? on negative peaks.?
15 kv? @ 11.7 amps = 175.5 kw modulation xfmr.? ?At the crest of the positive modulation,? B+ on the anode? is now? 30 kv....and plate current is now double at 23.4 amps.?
Let's assume plate modulation is not happening any time soon.?
They shoulda just run it grid driven, for linear service? like on the spec sheet.? ?200 kw pep out, and 50 kw cxr......which? swings to 75 kw.? ?That's 25 kw of total swing....( 25 kw of? total sideband power)..., with just 12.5 kw into each sideband.?
Still a wasted effort.? The 3x6 amp puts out 12.5 kw pep on ssb.?
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K6LPM
HaL Mandel
Mike Peace