Jim Brown napsal(a):
> 2-3kW? Is someone cheating on the rules? If you want to cheat, do your own
> designs and stay out of contests and DXing!
>
> My chokes are designed for 1.5kW. See my "Choke Cookbook" in
> http://audiosystemsgroup.com/RFI-Ham.pdf Note that #43 material is as good
> or
> slightly better ABOVE 5 MHz. #31 is much better on 80M and below.
>
>> I sent an email to lodestone but i had no reply.
>> Do you know where to buy them for a cheaper price or is there anyone to help
>> to buy them and send to me in Greece?
>
> Everything I know about buying them is in Appendix One of the latest version
> of the tutorial. Make sure you get it directly from my website to get the
> latest. I don't know if any of those vendors do business outside the US.
>
> Fair-Rite has distributors worldwide. See their website for listings and
> links.
>
> 73,
>
> Jim Brown K9YC
Oh, I would beg for stopping talks about cheating. BTW we in OK are
allowed to run 750 Watts any time, 2 kilowatts in contests and 3
kilowatts in contests if you are operating out of any densely populated
area.
This K9YC's explanation is very true:
> The key to not overheating them is to make the total resistance in the
common mode equivalent circuit very large, so that the current is very
small. In the case of the vertical dipole, which was really a method of
trying to push the choke hard enough to cause overheating, a single
choke did not provide enough resistance to achieve that, but two chokes
in series did. And remember, this test is FAR more severe than anything
the choke would see on an antenna that wasn't seriously broken! In my
test, it's the end insulator of a resonant half wave dipole that's
transmitting 1.5kW.
-------
Anyway I made my worst experience with _commercial_ products run up to
its nominal rating. Obviously a 1 kW rated part is good at 100W. I can't
keep quiet if I use my own design at its limit, a bad joint on the
antenna can change the things quite dramatically so an overrated part
(3-4x) makes me quiet :-) For commercial parts, at least made by
manufacturers, an overrate factor of 10 is not bad.
73,
Martin, OK1RR
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