BL-1 and BL1-1 Balun Questions
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Greetings folks;
I started building the balun kit, and I am suffering a bit of confusion, that I hope to get some help straightening out here. 1. In my ignorance, I cannot tell whether I am building a 4:1 or 1:1 balun; though the included instruction sheets are almost the same (the BL1 refers to a Binocular Balun core - I assume the ferrite core with parallel holes, the BL1-1 does not in the parts lists, both refer to winding the balun. They both refer to winding three turns around the balun core. So, ignoring the question of what I ordered for a minute, how do I tell which I am building? 2. There seems to be no way to get three turns around the core with the wire length provided; the instructions show what appears as the wires starting on one side of the core, through, around so on, so that you end up with 3 windings visible around the outside edge of the core, starting at one side and finishing at the other. I seem to be only able to get 2 turns, leaving 1" on one side, and about 2" at the other, with the windings pressed fairly tightly to the core. If I take the prescribed 10" length, subtract the 1" off both ends, I am left with 8" with which to get the 3 turns, the circumference of which calculates for me to be 3*3" or 9"... (I am assuming each turn takes 1" through, about .5" to make the turn, another 1" around, and another .5" to make the turn to go in, making 3" per turn) -.5" because the last winding need not turn and another .5" because the first "through need not turn either, so 9" - 1", = 8", the remaining length, so it would seem to be in theory possible. But in practice, I am failing to be able to perform this feat. I am hoping there is some simple if you know it trick to get me rolling again. Thanks in advance! --Dave -- David F. Reed - W5SV - cell: 512 585-1057 _______________________________________________ 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 |
RE: BL-1 and BL1-1 Balun Questions
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Hi David:
You asked about how to get the three turns on the BL-1 core. Three turns means that you see TWO loops of cable going down the outside to of the core on each side. (Remember, turns are *always* counted by the number of passes through the center of the core). For each hole, the wire starts at one end of the core, goes through the hole (that's turn 1), loops around the outside, back through the same hole (turn 2), around the outside the second (and last time) then goes back through the same hole (turn 3) one last time. Where it starts at one end you'll strip and solder to the terminals on the board near the coaxial input connector and where it ends at the opposite end you'll strip and solder the wires to the terminals at the output end of the BL1 board. I have a hunch you're trying to see three loops of wire around the core on the outside: that's why it won't fit and there isn't enough wire. That would make four turns! You wanted to know if you were building the 1:1 or 4:1 version. The ONLY difference between them is how the windings are connected at the output end of the board. If you hook the red and white leads to the circuit board pads as shown on the board - white leads to white pads and red leads to red pads, you'll have a 4:1 balun. If you want a 1:1 balun, connect the two white leads together and connect them to the pad marked WHITE nearest the edge with a number 2 on the board, then connect the two red leads together and connect them to the pad marked RED at the edge with the number 1 on the board. The inner "white" and "red" pads are not used. That's the only difference between the 1:1 and 4:1 versions. Ron AC7AC _______________________________________________ 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 |
Re: BL-1 and BL1-1 Balun Questions
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Ron,
thanks very much for the clear explanation; that was exactly what I was doing; I can get 2 visible turns around the outside just fine, and you explanation of the phasing making the ratio makes sense to me. Again, many thanks. --Dave-- Ron D'Eau Claire wrote: >Hi David: > >You asked about how to get the three turns on the BL-1 core. Three turns >means that you see TWO loops of cable going down the outside to of the core >on each side. (Remember, turns are *always* counted by the number of passes >through the center of the core). For each hole, the wire starts at one end >of the core, goes through the hole (that's turn 1), loops around the >outside, back through the same hole (turn 2), around the outside the second >(and last time) then goes back through the same hole (turn 3) one last time. >Where it starts at one end you'll strip and solder to the terminals on the >board near the coaxial input connector and where it ends at the opposite end >you'll strip and solder the wires to the terminals at the output end of the >BL1 board. > >I have a hunch you're trying to see three loops of wire around the core on >the outside: that's why it won't fit and there isn't enough wire. That would >make four turns! > >You wanted to know if you were building the 1:1 or 4:1 version. The ONLY >difference between them is how the windings are connected at the output end >of the board. If you hook the red and white leads to the circuit board pads >as shown on the board - white leads to white pads and red leads to red pads, >you'll have a 4:1 balun. > >If you want a 1:1 balun, connect the two white leads together and connect >them to the pad marked WHITE nearest the edge with a number 2 on the board, >then connect the two red leads together and connect them to the pad marked >RED at the edge with the number 1 on the board. The inner "white" and "red" >pads are not used. That's the only difference between the 1:1 and 4:1 >versions. > >Ron AC7AC > > David F. Reed - W5SV - cell: 512 585-1057 _______________________________________________ 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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In reply to this post by Ron D'Eau Claire-2
On page 62 of the manual, right side top, it states:
"You can connect any 7-14 V DC power supply or battery to J1, although you should use the minimum recommended voltage (8 V) when possible..." Why does Elecraft recommend that the KX1 only be run with 8 volts? That's even less that a new set of Lithium batteries would produce. Any comments? Matt - K7OE _______________________________________________ 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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Elecraft isn't recommending only 8V. They are recommending that you never go
BELOW 8 volts. Consider 8V the MIMINUM. Eric KE6US -----Original Message----- From: elecraft-bounces+eric_csuf=[hidden email] [mailto:elecraft-bounces+eric_csuf=[hidden email]] On Behalf Of [hidden email] Sent: Thursday, May 26, 2005 9:41 AM To: [hidden email] Subject: [Elecraft] KX1 Voltage On page 62 of the manual, right side top, it states: "You can connect any 7-14 V DC power supply or battery to J1, although you should use the minimum recommended voltage (8 V) when possible..." Why does Elecraft recommend that the KX1 only be run with 8 volts? That's even less that a new set of Lithium batteries would produce. Any comments? Matt - K7OE _______________________________________________ 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 _______________________________________________ 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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