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VHF antenna anomaly
----- Original Message -----
From: "brian whatcott" Newsgroups: rec.boats.cruising Sent: Tuesday, November 24, 2009 7:24 AM Subject: VHF antenna anomaly Solid dielectric, double shield, preferably not pvc sheath which gives off acid decay products. Choose the correct characteristic impedance. Coax is offered in 50 to 70 ohm impedance. Above all: minimize I said MINIMIZE the number of BNC coax connections. They are lossy. You could consider low loss type connectors but it adds to the general confusion and cost I know. I hope you don't mean what I THINK you mean when you talk about jumpers. NO WIRE JUMPERS! Brian W Hi, Brian, Yes, when I said jumper I was referring to a short length to extend, or, in the particular post, just use as a very short feed line, to test the antenna (having previously proven the radio good). I have (in the end result) either 3 or 4 connectors, depending on how you look at it. First is at the radio. Second is at the connector which had to be bolted, so to speak, to the bracket, as the metz antenna threads don't go all the way through it. However, having said that, in my test which proved the antenna and the radio, I note that the metz has a very long male inside of it, a nylon bushing keeping the antenna feed short enough, against it, and then the connector piece which doesn't have threads all the way through it. If you look at my gallery, under SSI refit, then upgrades/electronics, you'll see the bulkhead connector I had to use to get the Metz stem long enough to connect, and the end result on the bracket at the top of the mast. Numbers 3 and/or 4 would be the double male adapter I had to mount to the top of that bulkhead connector to make the metz mount on it. HOWEVER, you've stimulated a thought which I presume would work: If I take that nylon bushing, stick it back in the Metz, and screw the body of the coil onto my bulkhead connector, that connector should replace the Metz stem reducing the connectors by either one or two. Thanks for stimulation; let me know, any of you, who find fault with that conclusion (replace the Metz stem with the bulkhead connector). So, if you conclude that the antenna itself should not be counted in connectors, I'd have two - one at the radio, and the other at the antenna. Am I correct? L8R Skip Morgan 461 #2 SV Flying Pig KI4MPC See our galleries at www.justpickone.org/skip/gallery ! Follow us at http://groups.yahoo.com/group/TheFlyingPigLog and/or http://groups.google.com/group/flyingpiglog "You are never given a wish without also being given the power to make it come true. You may have to work for it however." (and) "There is no such thing as a problem without a gift for you in its hand (Richard Bach) |
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