Posted: 1/22/2011 8:34:48 PM EDT
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km's VHF contest got me looking at antennas for VHF/UHF. I have an IC7K, which has 2 antenna ports on the back of it: 1 for HF+6M, and 1 for 2m/70cm. If I had an antenna that I wanted to use for 6m/2m/70cm, how would I cable this critter up to my radio? Or could I? Stumped, or stupid –– one of the two  Thanks, -Slice |
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Quoted: km's VHF contest got me looking at antennas for VHF/UHF. I have an IC7K, which has 2 antenna ports on the back of it: 1 for HF+6M, and 1 for 2m/70cm. If I had an antenna that I wanted to use for 6m/2m/70cm, how would I cable this critter up to my radio? Or could I? Stumped, or stupid –– one of the two Thanks, -Slice You could get 2 A/B antenna switches and 1 coax double adapters....but you'd need to switch them everytime you changed from HF to 6 meters to 2 meter/440. |
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all you would need is a 2 antenna switch on the HF antenna connector. your HF antenna would go on one and your 6m antenna would go on the other. your VHF/UHF wouldnt require anything special unless your running a dedicated VHF and dedicated UHF antenna. then you would need another switch. at least thats my understanding.
edit, woops, helps to read. one question, why would you run a 6/2/70 single antenna? room restrictions or some other reason to not run a 2/70 and a stand alone 6? |
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Well, I'm a long way from actually getting anything yet, I was just lookin'. But, one of the things I came across was this: http://www.cometantenna.com/products.php?CatID=1&famID=5&childID=13. It's a log periodic that'll do 50-1300 MHz. The only tower I have is an old TV tower about 40' tall and made mostly out of rust. I figure this thing is not much bigger than the unused TV antenna that's up there, so the tower could probably support it. No way I'd feel comfortable w/ 3 beams up there. So, I guess my tower is my limitation. I realize it's not as good as a performer as a dedicated beam for either 6, 2, or 70cm in terms of either gain or beam width, but for me it might be one of the only ways I'll be able to get on the air on those 3 bands w/ SSB/CW. Today my tuner will tune my HF wire antennas on 6m, but I think they're mostly coax warmers. I've never heard a signal on 6m before. Certainly open to better ideas! Thanks, -Slice |
| the only thing i dont like is there lack of information on there product. i can see where your coming from though. limited to what you already have, it depends on what you want to run. are you going to use 6m that much or just for contest? what about doing a home brew just for 6 and put it up as needed? to much work? |
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IF you have one antenna for 6m up and a split HF/6m and 2m/440 here's what I would end up doing.
Run a duplexer in "reverse" meaning the antenna goes in one end and then two separate outs. One to 6m and the other side to 2m up. Then run a switch to go between the 6m in and regular HF in. You may even be able to get a 30mhz down/up duplexer to split out 6m and HF and do away with the switch completely. Not pretty, but it could be done. |
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For 3-band amateur use you can do better than those log periodics with similar windload. Can probably even homebrew it by recycling a couple of TV antennas... a 3 element 6m yagi along with a 2m+432 using parasitically driven elements for 432, all on one boom. This would give you separate 6 and 2/432 feedlines along with reasonable performance on all three bands. Simple coax switches on each radio port would switch to HF antenna/tuners, dual band vertical for FM, etc.
Here's the dual band yagi, in a 5 element 2m / 8 element 432 version. http://www.mydarc.de/dk7zb/Duoband/5+8_2m-70cm.htm |