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#1
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* Brian Kelly [07/17/2005 02:19 UTC]:
The wire should outperform the 6BTV by a large margin IF you have an even half-decent counterpoise/grounding system in place like a wire-over-the-roof plus Reg's plumbing system connections. You'd also get much more bandwidth with a wire vs. the 6BTV. A random wire can be used on 30M, a 6BTV cannot be used on 30M, etc. Excellent info, thanks! You can put up a wire and buy a manual wire tuner like the $110 MFJ 941E plus the cost of the wire. I'll do the tuning manually and save $150-200 additional cost for any autotuner every time. Yeah, $140 difference. Question about that though... wouldn't the AH-4 be a better choice for another reason? That reason being that the AH-4 is designed to connect to the wire directly at the feed point, whereas the MFJ is apparently designed for in-shack use. -- -=Elden=- http://www.moondog.org |
#2
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Elden Fenison wrote:
* Brian Kelly [07/17/2005 02:19 UTC]: The wire should outperform the 6BTV by a large margin IF you have an even half-decent counterpoise/grounding system in place like a wire-over-the-roof plus Reg's plumbing system connections. You'd also get much more bandwidth with a wire vs. the 6BTV. A random wire can be used on 30M, a 6BTV cannot be used on 30M, etc. Excellent info, thanks! You can put up a wire and buy a manual wire tuner like the $110 MFJ 941E plus the cost of the wire. I'll do the tuning manually and save $150-200 additional cost for any autotuner every time. Yeah, $140 difference. Question about that though... wouldn't the AH-4 be a better choice for another reason? That reason being that the AH-4 is designed to connect to the wire directly at the feed point, whereas the MFJ is apparently designed for in-shack use. That's quite true. But it's also true that the large majority of hams who use end-fed random length wire antennas run the fed end of the wire and a ground wire into the shack to manual tuners located near their xcvrs. I've done it many times over many years and never had any big problems with this kind of layout. The biggest concern in this topic area is running the antenna and ground wire thru a window or wall to a manual tuner or in the case of a remote autotuner like the AH-4 the coax and control/power cable. It's six of one and a half-dozen of the other in this regard, there is no way out of having to run "something" from the outside to the operating posiition wires or cables, take your pick. The tradeoff you're facing is is spending $140 more to run a couple cables thru the wall or window than it costs to run a couple wires thru a wall or window. Which makes no sense to me. There are worry-warts all over hamdom who get into an uproar over the thought of having "RF hot" wires coming thru their walls and windows to the operating position. That's utter nonsense unless very high powers are involved in which case neither the AH-4 or the 941 can be used. I'm usually able to install the operating position very close to a window. I get a length of 2" wide x 3/4" thick rectangular trim molding and cut it to the width of the window frame so that when the window is closed on it the weather is sealed out. For an insulated feedthrough widget I cut a 6" length of coax, usually 8X and strip the braid back two inches on both ends then I strip the dielectric back and inch on each end. Then I wrap the whole assembly with electrical tape to seal it while leaving just the center conductors bare on both ends. I drill holes thru the molding and install the "feedtrough insulators" thru the holes and secure it in place with one of the hardware store "goops" used for weather caulking. With the strip of wood in place I solder the antenna and ground wires to the outer pigtails of the contraption and solder insulated wires to the inner pigtails thence to the tuner, close the window and get on the air. Fact is though that as often as not I've simply run the insulated antenna and ground wires thru small holes the wood and called it a day. There's ALWAYS a way . . . The caveat here is whether or not the operating position is located within a few feet from the penetration point. Cables can be run on the floor or along the wall to just about anywhere in your apartment. Wires should not be willy-nilly run on floors or walls for a number of reasons. If the operating position cannot be located close to the penetration point you don't any choice, you'll need an AH-4 or one of it's competitors. Or put up a coax-fed single-band dipole and you won't need any type of tuner and the operating position can be anywhere in your abode. -- -=Elden=- w3rv |
#3
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Elden Fenison wrote:
* Brian Kelly [07/17/2005 02:19 UTC]: The wire should outperform the 6BTV by a large margin IF you have an even half-decent counterpoise/grounding system in place like a wire-over-the-roof plus Reg's plumbing system connections. You'd also get much more bandwidth with a wire vs. the 6BTV. A random wire can be used on 30M, a 6BTV cannot be used on 30M, etc. Excellent info, thanks! You can put up a wire and buy a manual wire tuner like the $110 MFJ 941E plus the cost of the wire. I'll do the tuning manually and save $150-200 additional cost for any autotuner every time. Yeah, $140 difference. Question about that though... wouldn't the AH-4 be a better choice for another reason? That reason being that the AH-4 is designed to connect to the wire directly at the feed point, whereas the MFJ is apparently designed for in-shack use. Yes and no, it's a matter of several tradeoffs Elden. Right now I'm up to ears in alligators so QRX and I'll get back to you late Monday with some comments. -=Elden=- http://www.moondog.org w3rv |
#4
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* Brian Kelly [07/17/2005 22:19 UTC]:
Yeah, $140 difference. Question about that though... wouldn't the AH-4 be a better choice for another reason? That reason being that the AH-4 is designed to connect to the wire directly at the feed point, whereas the MFJ is apparently designed for in-shack use. Yes and no, it's a matter of several tradeoffs Elden. Right now I'm up to ears in alligators so QRX and I'll get back to you late Monday with some comments. Ok Brian. I appreciate the advice you've given. I do understand that there sometimes is disagreement between hams regarding certain things, like having a portion of a radiating element in the shack. Personally, I think I'd opt for an outdoor-mounted AH-4 for reasons of efficency, convenience, and safety. But it is nice to know that other options exist. So right now, my preferred solution is an ICOM IC-718, with an AH-4 and a longwire. I think that should work nicely. After surveying the new apartment location a little more closely, looks like I could run a horizontal longwire, roughly parallel to the ground for 100ft into a tree with some sort of insulator on the end. Then I would do the "in apartment" counterpoise/RF ground. This would probably be about 20/30ft off the ground... second floor height. Regarding your explanation for getting various wires from indoor to outdoor, I've taken the exact same approach. Using a thin 2x2 in the window with cables running in through an opening in it. Seems to work ok and no permanent holes in the structure. -- -=Elden=- http://www.moondog.org |
#5
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Elden Fenison wrote:
* Brian Kelly [07/17/2005 22:19 UTC]: Yeah, $140 difference. Question about that though... wouldn't the AH-4 be a better choice for another reason? That reason being that the AH-4 is designed to connect to the wire directly at the feed point, whereas the MFJ is apparently designed for in-shack use. Yes and no, it's a matter of several tradeoffs Elden. Right now I'm up to ears in alligators so QRX and I'll get back to you late Monday with some comments. Ok Brian. I appreciate the advice you've given. I do understand that there sometimes is disagreement between hams regarding certain things, like having a portion of a radiating element in the shack. Yeah, everybody has different opinions and experiences with this topic. Personally I've never had a problem in the shack with wires that I didn't also have when using a coax-fed antenna which is located anywhere near the shack. Maybe I'll get a dose of it eventually and have to eat my words. Personally, I think I'd opt for an outdoor-mounted AH-4 for reasons of efficency, convenience, and safety. But it is nice to know that other options exist. So right now, my preferred solution is an ICOM IC-718, with an AH-4 and a longwire. I think that should work nicely. You made the tradeoffs and there ya go. Sure it'll work. After surveying the new apartment location a little more closely, looks like I could run a horizontal longwire, roughly parallel to the ground for 100ft into a tree with some sort of insulator on the end. Then I would do the "in apartment" counterpoise/RF ground. This would probably be about 20/30ft off the ground... second floor height. I dunno . . I'd expect a wire strung vertically as far as possible up into that 100 ft tree to work a *whole* lot better than a low horizontal wire even if the vertical is shorter. Keep in mind that trees move around and the wire will be tensioned or droop when the wind is up. I've had a couple wires break and I've also had one dipole drop because the rope running from the end of the antenna to ground level wore thru. Another discussion. Regarding your explanation for getting various wires from indoor to outdoor, I've taken the exact same approach. Using a thin 2x2 in the window with cables running in through an opening in it. Seems to work ok and no permanent holes in the structure. You're set. Good luck. -=Elden=- http://www.moondog.org w3rv |
#6
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* Brian Kelly [07/18/2005 16:38 UTC]:
You're set. Good luck. Thanks again for all the tips. 73 -- -=Elden=- http://www.moondog.org |
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