Greetings All,
Ok, I want to build a balun. It should be able to handle 200 Watts RF (safety factor built into this number), 80 thru 30 Meters (160M would be nice) and be efficient. I want to use a Toroid to do this so it fits inside an enclosure. My question is how small of a toroid can I use and which variety? I'm thinking something in the T-100-6 range. Thanks, Julius n2wn _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
Julius Fazekas
N2WN Tennessee Contest Group http://www.k4ro.net/tcg/index.html Tennessee QSO Party http://www.tnqp.org/ Elecraft K2 #4455 Elecraft K3/100 #366 Elecraft K3/100 |
Hello Julius
> Ok, I want to build a balun. It should be able to > handle 200 Watts RF (safety factor built into this > number), 80 thru 30 Meters (160M would be nice) and be > efficient. Well, I'm guessing here, but I think you'll need to use ferrite to keep the inductance reasonable. You also want to keep the B field low so it doesn't get hot or non linear. Let's shoot for 200 gauss peak. If you were running 200 watts into 50 ohms, you'd need 100 volts on the line, but that would be into a matched load. Into a doublet lets say we have a 10:1 VSWR, so we'll see 1000 volts at the balun. How many turns? Lets try 10. Frequency, 1.8 MHz. Using Fair-Rite's formula, we'll need 6.26 cm squared core area. If you use FT-100-43 I think you'd need to stack them up until you have a 1" diameter by 5" long tube. I might be way off though. 73, de Michael, AB9GV _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
All the hard work of balun design has been done in the balun kit offered by
The Wireman, Landrum S.C. (on web). I believe Amidon might also have Balun kits and both fit the power range you want. Typically, it is hard to get one balun to work 160m to 10m. See the Jerry Sevick books, (Baluns and Ununs) for worked out examples that never get hot. -Stuart K5KVH _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
In reply to this post by Julius Fazekas n2wn
Julius,
Off hand, without doing the design, I'd say something on the order of one F-140-43 or two F-114-43. You can't get there with a T-XX-6; not enough umph. Takes F-XX-61 at the least. Why limit it to 160 to 30 meters? The BL-1 covers 160 through 6. See http://www.njqrp.org/balun/index.html Chas, W1CG At 02:25 PM 10/12/2004, J F wrote: >Greetings All, > >Ok, I want to build a balun. It should be able to >handle 200 Watts RF (safety factor built into this >number), 80 thru 30 Meters (160M would be nice) and be >efficient. I want to use a Toroid to do this so it >fits inside an enclosure. My question is how small of >a toroid can I use and which variety? I'm thinking >something in the T-100-6 range. > >Thanks, >Julius >n2wn _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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