[Amps] 10 kw CCS on 6M

[Donald Fox]

 John:
Thanks for stepping in for a moment. I've been "reading the mail" here for years. Just like the sweet song of a high horsepower engine, it's something to participate, or at least watch when such a piece of RF hardware is fired up, even if it's only to a big dummy load. 

We all know that the internet is a mixed blessing. Lots of good stuff, but also very bad if one seeks it out. I find it quite amazing, to watch a VOA or similar class transmitters being brought up, and put online. I've lived no more than an hour away from Bethany, Ohio which many know was a VOA site until 1994.
Near by WLW in Mason, Ohio is on the air today covering 37 states at night, and 9 in the daytime if I recall correctly, with 50kw on 700kc.

There is quite a history there, back when WLW ran 500kw! That figure is hard to wrap my brain around, as we are talking brute power, before any sort of antenna gain came into play. The sheer magnitude of such an operation, and the fact that this amount of RF could be generated in one place back when they did it, is quite a feat in my opinion.

Water cooling, and a bunch of plate amps, at thousands of plate volts. Our typical home 240V 200 amp electric service is good for roughly 48kw input, on a good day. 
Doubling, or tripling that 200 amp service is still peanuts compared to such an operation.

Don N8ECH
     On Saturday, September 10, 2022, 02:49:18 PM EDT, John Lyles <jtml at losalamos.com> wrote:  
 
 I saw you mention K5PRO, Don, so I had to come out of my shell. I have 
watched the 10 kW homebrew videos too. Admirable work, makes me long for 
time to do modern tube-based amplifier construction at home, but I 
prefer less spend the time with a camera. Even could fix some of my 
trove of half-way good amplifiers. I don't use them on the air much, 
just love to play with them. I still have my job, and switched to part 
time this week so I could spend a little more time at home. At the 
workplace, the particle factory, most of the PA's are getting >45K hours 
on the filament running 24/7 for 2/3 of each year. I am happy to have 
been part of their development. All the proper guidelines, cooling, 
running within ratings (not at ratings), and plenty of protective 
circuitry has paid off. Right now, we are looking at various 
improvements and I'm working with a young team of EE's willing to ask 
questions and dig in, about these ancient things, tubes.  We have to 
keep the technology going, and when its hundreds of kW or megawatts, the 
alternative solid state must be carefully examined.

Here is an interesting recent paper from a conference last month, about 
the advantages of tubes in the drivers for the Berkley 88 inch 
cyclotron. Some things we never think about in ham radio are here. This 
is a short term link that will be active about a week:

https://we.tl/t-4nZK77BSMm

One more paper, I wrote last month for the same conference of particle 
accelerators in US:

https://we.tl/t-mogwvszTZh

My heart is still in thermionic devices although I do use LDMOS, DMOS, 
GaN, and other semiconductors for smaller PA's at work (< 25 kW), but I 
haven't designed a transistor amplifier in decades myself. So many 
decent designs seem to be around now, and its good to see the amateur 
community has engaged this techology. For those who still like using 
tubes, like tuning the grid and plate, amps at contesting.com is still the 
place to keep up, if you like this format as opposed to Facebook.

Speaking of tubes, I prepared a lecture at work in July, that summarizes 
a lot of information about tubes, specifically focused on a historical 
overview, then high power tubes used in pulsed power and RF circuits at 
work. I used a lot of part numbers that are in service there, so there 
are some references mentioned, just ignore those. This has been cleared 
for public release.

https://we.tl/t-Blv0xVNOnQ

73

John K5PRO


> Message: 1
> Date: Sat, 10 Sep 2022 01:41:40 +0000 (UTC)
> From: Donald Fox <taurusshoguy at yahoo.com>
> To: amps at contesting.com
> Subject: Re: [Amps] 10 kw CCS on 6M. Part-3
> Message-ID: <887692576.944216.1662774100648 at mail.yahoo.com>
> Content-Type: text/plain; charset=UTF-8
>
>  
> As we like to say on the car forums I frequent, I'll be "that guy."
> I think the project is great, and I'm glad it's being shared here. Last time I looked, this IS an amplifier reflector, correct?
>
> This hoity, toity nonsense of hams sticking their nose up in the air when someone asks a question, or heaven forbid, shares something like this project, is getting really old. Reminds me of Eeyore on Winnie the Pooh. Just like the car forums I frequent, I listen a lot, and add to the conversation when I feel I can lend help.
> It's been my understanding for the 41+ years I have enjoyed this hobby, that part of ham radio, is the encouragement to design, and/or build some of your equipment. Seems to me like that is what this fellow is doing.
> Nobody knows everything, although there are some here who think they do. I know I don't, and have zero trouble putting it out there.
>
> As mentioned already, just because you have a fast car, does not mean you drive it fast on a public roadway. With 25+ years of law enforcement experience here, I am not aware of any state, that limits how FAST one gets to the speed limit, as ,long as they are not dangerous or out of control doing it.
>
> There is a video on Youtube, where a west coast 11 meter fellow designed and built his own 50kw amp. Indeed, putting it on the air is illegal as all get out, BUT if you a know anything about high power, he's no dummy. I would welcome someone with that level of high power experience (John K5PRO) comes to mind, in a heartbeat.
>
> It is said, that money does not guarantee brains. Neither does a ham license. All one has to do is dial up 7.200 or similar. Garbage like that makes ALL of us look bad to a potential ham.
>
> Rant mode off!
>
> Don N8ECH
>
>    
>
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