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#1
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All those commercial antennas will work better at thinning your wallet.
But not at getting your signal out. The only way you'd improve over the signal from a cut-down CB whip (2 minutes work with a hacksaw) is to either make the antenna directional in azimuth which would decrease the signal in other directions, or try making a collinear array. And I seriously doubt that you could get any noticeable gain from a collinear without making it too tall to be practical. I'm glad that some hams are still willing to reach for the hacksaw instead of the wallet. Go for it! Roy Lewallen, W7EL Dave wrote: Have you heard of a 10 meter mobile antenna?? Hamstix, Hustler, et al make them. Lot easier than trying to cut steel. Merlin-7 KI4ILB wrote: I just bought a 10 meter mobile rig (25 watt old radio shack rig). I was planing on cutting down a 102" CB whip to 10 meter band. Anyone know of any type of antenna that would work better? Thanks Joe KI4ILB |
#2
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Thanks everyone
It will be mounted to the side rail of my Dodge 1500 4 door along with the 6 foot coliner for 2m and the 11 meter whip. Yes it has a CB in it. I need the CB for talking to truckers when I go into hurricane hit areas a day or two after the hurricane. Finding out what roads are open, last place to get fuel etc... Now all I need to figure out is how to keep the 10 meter and 11 meter antennas from interacting too bad or place them in such a way that the interaction does something that is usefull... Joe |
#3
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Merlin-7 KI4ILB wrote:
Now all I need to figure out is how to keep the 10 meter and 11 meter antennas from interacting too bad or place them in such a way that the interaction does something that is usefull... Here's an idea. Use the 11 meter antenna for 10 meter operation by switching in a series capacitor. All you need to do is to neutralize the small amount of inductive reactance on 10m caused by the antenna being a tad too long. The capacitor could be switched in and out by a relay. I get a value of ~330 pf to perform that function. The SWR on 10m will actually be better than it is on 11m. Or you could use the capacitor with the second 102 inch vertical without having to cut it. -- 73, Cecil http://www.w5dxp.com |
#4
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In message , Cecil
Moore writes Merlin-7 KI4ILB wrote: Now all I need to figure out is how to keep the 10 meter and 11 meter antennas from interacting too bad or place them in such a way that the interaction does something that is usefull... Here's an idea. Use the 11 meter antenna for 10 meter operation by switching in a series capacitor. All you need to do is to neutralize the small amount of inductive reactance on 10m caused by the antenna being a tad too long. The capacitor could be switched in and out by a relay. I get a value of ~330 pf to perform that function. The SWR on 10m will actually be better than it is on 11m. Or you could use the capacitor with the second 102 inch vertical without having to cut it. I did exactly this (20 years ago). I used a variable compression trimmer capacitor to check that I could actually get a low SWR, measured it, and fitted the nearest value disc ceramic (rated at 500VDC). I think it was 330pF. No problems with 40W. Ian. -- |
#5
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OK where can I buy a 330pf cap? Its only a 25 watt rig but I would like a
bit of overkill. ****es me off that Radio Shack is a cell phone store now. I used to be able to walk into Radio Shack and the person there would understand what you needed. Now if it does not have to do with cell phones or car audio they just give you this dumb look.. Thanks Joe vertical without having to cut it. I did exactly this (20 years ago). I used a variable compression trimmer capacitor to check that I could actually get a low SWR, measured it, and fitted the nearest value disc ceramic (rated at 500VDC). I think it was 330pF. No problems with 40W. Ian. -- |
#6
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Merlin-7 KI4ILB wrote:
OK where can I buy a 330pf cap? Make it a silver mica or doorknob. I get mine at an electronics supply store in Bryan, TX, close to Texas A&M. Where are you located? -- 73, Cecil, http://www.qsl.net/w5dxp |
#7
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"Now if it does not have to do with cell phones or car audio they
just give you this dumb look.. " Heh.. went into my local Radio Shack and asked if they had any antenna masts in stock. Guy goes and looks on the shelves. I say "I'd like a TV mast, it's in the back if you have it, it's ten feet long" Guy looks on the shelves some more, points to the mast brackets. I'm like, "It's a ten feet long piece of steel pipe it wouldn't be out here, it isn't out here, it wouldn't fit out here, it's in the BACK." I look it up on the internet on the computer in the store and show them that yes, they do have them in stock. Of course, he doesn't think they've got any. Twenty minutes after I walk in, I'm finally leaving with a five foot and a ten foot mast section which they, of course, had. Guy is just incredulous that I'm going to walk out of the store with a ten foot piece of pipe. They then ask me if I need a cell phone ;-) Dan |
#8
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On Thu, 26 Oct 2006 22:53:48 GMT, "Merlin-7 KI4ILB"
wrote: OK where can I buy a 330pf cap? Its only a 25 watt rig but I would like a bit of overkill. ****es me off that Radio Shack is a cell phone store now. I used to be able to walk into Radio Shack and the person there would understand what you needed. Now if it does not have to do with cell phones or car audio they just give you this dumb look.. Thanks Joe I've been able to mail order most any electrical part from Mouser. No minimum order. And it puts you on the list for their huge catalog. bob k5qwg vertical without having to cut it. I did exactly this (20 years ago). I used a variable compression trimmer capacitor to check that I could actually get a low SWR, measured it, and fitted the nearest value disc ceramic (rated at 500VDC). I think it was 330pF. No problems with 40W. Ian. -- |
#9
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Ok which one would you recommend?
http://www.mouser.com/search/Refine.... f&N=1323038+0 Thanks joe I've been able to mail order most any electrical part from Mouser. No minimum order. And it puts you on the list for their huge catalog. bob k5qwg vertical without having to cut it. I did exactly this (20 years ago). I used a variable compression trimmer capacitor to check that I could actually get a low SWR, measured it, and fitted the nearest value disc ceramic (rated at 500VDC). I think it was 330pF. No problems with 40W. Ian. -- |
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