Jim, You'll see I said "it's about stopping the ladderline, and more importantly the coax, from becoming part of the radiating structure." The reason I suggest that CM on the coax is more problematic
Yes! Steve G3TXQ _______________________________________________ _______________________________________________ TowerTalk mailing list TowerTalk@contesting.com http://lists.contesting.com/mailman/li
Bill, Steve G3TXQ _______________________________________________ _______________________________________________ TowerTalk mailing list TowerTalk@contesting.com http://lists.contesting.com/mailman/l
I can see no advantage in an antenna like that - even the copper loss begins to be significant. The pattern is bad enough on 160m and 80m; I can't model it on higher frequency bands because I exceed
Tom, Air cored chokes tend to be quite narrow-band - that means using the right number of turns of the correct diameter is critical to getting high choking impedance at your operating frequency. Even
Let's say there was 5pF from each side of the choke to the boom - that's 2.5pF net. At 30MHz that's a reactance of 2000 Ohms shunting the choke. Not sure if that makes a difference in your applicatio
Jim, Just one correction: the length of boom in series with the capacitors represents an Inductive reactance provided it's less than a quarterwave long; that actually has the undesired effect of canc
Hi Charlie, Not sure what your budget is, but I've been very happy with my LP-100 from Telepost. Not only will it read peaks, it'll estimate the amount of compression on your signal, and it'll give y
Take a look at the losses and where they fall: http://vk1od.net/antenna/cobra/index.htm 73, Steve G3TXQ _______________________________________________ _______________________________________________
The military love them because they value frequency agility over efficiency. Cebik's analysis put the power in the terminating resistor at somewhere between half and 90% of the applied power, dependi
Here's what some folk would call a "real" Fan Dipole: http://www.karinya.net/g3txq/temp/fan.png The 5 pairs of shorter legs are all exactly the same length. And here's a VSWR plot: http://www.karinya
Looks like you would have plenty of room for an 80m Inverted-L with the vertical section at the far end of the yard away from the house and the horizontal section running back towards a tie-off point
Yes, if it's a 4:1 Guanella balun. Steve G3TXQ _______________________________________________ _______________________________________________ TowerTalk mailing list TowerTalk@contesting.com http://l
Jim, I thought he said 100ft ? 73, Steve G3TXQ _______________________________________________ _______________________________________________ TowerTalk mailing list TowerTalk@contesting.com http://l
If you research the origins of that urban myth about bumblebee flight defying the laws of physics you'll find some interest parallels with antenna modelling! In short, the supposition that a bumblebe
You're quite mistaken - none of the Laws of Physics had to be adjusted. What changed was that they were applied more completely to the problem instead of making simplifying assumptions - that's a qui
Barry, I wonder if it was an UnUn rather than a BalUn. Sevick shows a simple 2.25:1 UnUn transformer comprising a trifilar winding on a single core. I can't think of any way you'd do a true 2:1 TL Ba
That Balun Designs model is a 2.25:1 UnUn connected to the unbalanced port to achieve the impedance transformation, followed by 1:1 current balun on the load side to achieve the balance. Steve G3TXQ
I doubt you'd notice any difference. I've made loss measurements and balance measurements on my Palstar BT1500A balanced tuner with a range of different load impedances, and compared them to my unbal
I'm surprised there was so much difference with the AIM results; I've made the same comparison myself and not seen anything like that sort of difference. I wonder how you calibrated the AIM4170 befor