I would like to replace the coax from my cloud burner loop with Ladder Line. I have looked through the Handbook and other antenna books and have found information on running ladder line past/over lar
If the ladder line is 450 ohms, and well matched at the operating frequencies, Palomar makes a nice 9:1 transformer that goes balanced 450 to unbalanced, I think three 150 ohm lines around a core. In
Jim, the route you've outlined sounds fine, and if you follow a few basics along the way your operating problems should be minimal, as well as solvable, if any. 1. On the route, minimize the number o
If you keep it a few inches from conductors (in general) it should work pretty well. I would give the wire a twist (spriral) about 1 complete turn per foot or so. This will tend to even out the capa
Author: jerrymorris@worldnet.att.net (Jerry Morris - W5MS-W5KUF-Corpus Christi Amateur Radio Club)
Date: Mon, 26 Apr 1999 15:27:00 -0700
connect 2 -75 ohm cables together side by side......connect shield together at both ends..... use center conductor for each side of ladder line.....do not ground shield......been using this system on
Jim, Unless your a using a Johnson matchbox (no balun), put the balun at the window interface and run a piece of 3/4" or 7/8" hardline the rest of the way. Mike, W4EF............. I would like to rep
Author: Guy Olinger, K2AV" <k2av@qsl.net (Guy Olinger, K2AV)
Date: Mon, 26 Apr 1999 23:00:03 -0400
Curious as to why you don't ground the shields. Grounding the shields was the only way I could get rid of some florescent lamp noise. It changed the tuner settings just a smidge. I suspect that if th
In this month's (May) issue of QST, on page 53, they show using coax for parallel conductor line and they show the shields tied together at both ends but only the TX END of the shields grounded to TX
To anyone, What is the impedance of the two 75 ohm cables in parallel? Is it close to 450 ohms so that you just hook it up directly to the end of a long run of 450 ohm open wire feeder????? Thanks, M
Mike: The impedance should be about 150 ohms (balanced). And if I recall what I was taught years ago, there's really no significant penalty to be paid by just connecting the two lines together... esp
It turns out to be somewhat less than twice the impedance of the lines taken separately. Double 75 coax used as a balanced feedline was called 130 or 135 ohm at AT&T. Someone know the reasons why? (W
(Was used a lot in baseband analog video where pickup of hum noise was a real problem. They've gone digital now, of course...) ==snip== The 135 ohm cable Guy references is (was) twisted pair in a sin
window interface HI All In regards to the balun, how does it work when the impedance of the line keeps changing? If you use a 4/1 balun, some frequencies will be 300 ohm impedance and it will work, b
Not so. If the lines are operated in parallel, the impedance is 37.5 ohms. If they are operated in push-pull, they are 150 ohms. The loss is exactly the same as a single cable of the same length wit
-- Tom, A 1:1 choke balun is called for and a very short length of coax to the tuner. 73, Bob, W5AH -- FAQ on WWW: http://www.contesting.com/towertalkfaq.html Submissions: towertalk@contesting.com A
Hi Tom - this is a question we deal with over and over again, and have sold hundreds of heavy duty baluns and kits for the purpose. A 10 ft max run is suggested, and the balun is one Lew McCoy tested
Hey Tom, That's right Tom. If the line is mismatched by a large amount, the last thing you want to use is a voltage balun or any balun that places a winding directly in parallel with either the input
BOB, I think you are mistaken on the balun...it should be 4:1 or greater. This is what Radio Works recommends/sells and I homebrewed a 4:1 for my HB 600 ohm open wire line and it works great. HAVE FU
I know that stuff too. In an analog LD switching office there were tons of it at the channelbank/group level. 135 ohm shielded twisted pair. But what I was talking about was two pieces of coax held s