"Unlikely" isn't strong enough, it would be impossible. I can buy the cheapest radio shack coax, the type that you can see through the shield to the center dielectric, and it is nearly impossible to
Playing in a lab somtimes has little bearing in a real world situation. With a reactive load as would exist with many commercial and home brew antennas leakage is not only possible but very likely.
I suspect that a crummy shield would have a larger effect on IR losses than on anything else. But, since the surface area of the shield is so much larger than the center conductor, I would think that
I do not think that's true. Can you give an example and the mechanism by which anything connected at the end of the coax would change the propagation "through" the shield? I can believe currents indu
It has been observed (by N6BV and others) that in most coax, losses are primarily IsquaredR below about 500 MHz, and primarily in the dielectric above that frequency. Obviously, that's a broad genera
So, for "cable TV" kinds of applications, the extra resistivity from using an aluminum shield probably isn't as big a deal: 75 ohms makes larger diameter ratio, and dielectric losses starting to be a
How did you measure yours? Or is this just a gut feeling? _______________________________________________ _______________________________________________ TowerTalk mailing list TowerTalk@contesting.
The fact that it's mismatched isn't going to put any current on the outside (unless it's also unbalanced), but looking at the current on the inside of the braid.. OK.. a dipole in free space cut for
When "cyborg" comes into fashion, I'm going to get a VNA built into my gut so I can calibrate the feelings ;-) Dan _______________________________________________ ___________________________________
<Snip> That all makes sense Carl, and I certainly don't dispute what you saw, but respectfully this is what gets many of us into trouble in understanding how systems work. Without really measuring a
In a RF screen room doing Tempest testing for the CIA. The results convinced me to go hardline at home. I try to leave gut feelings and magic out of the equations ____________________________________
We have to be careful here. The leakage is >60dB but that is in a special standard test fixture at virtually zero spacing to the cable in a closed box. It doesn't mean if we have 1000 watts applied
Helluva story, Carl! (It must really focus the mind to know that, one way or another, you were going to leave that ship by catapult. ) But Jim made two separate points there: the % shield; and also t
The leakage from a coaxial cable is only indirectly related to the braid coverage and/or 'hole size'. It does not leak out of the holes like water through a sieve! What happens is that the coaxial mo
I didnt want to belabor the forum with all the details last night and my time was limited. As mentioned we also carried a leakage tester and that was used extensively while also isolating decks and
I never stated that heating was ever a part of this thread, perhaps you are referring to someone else. However I have come close to burning my hand once many years ago while at a friends home trackin
Hi Ian, nice to here from you, its been ages! As far as the ship problem "Not at all" still holds. The network did not use PL259's, they are not even constant impedence. The installer used inferior c
Thank you for that explanation Roger. Since there was no question about the connector integrity and the long lengths laying in cable trays were next to all types of other cables, RF and power, your e
Contrary to as stated by the other poster; "transfer impedance" does NOT remain constant with frequency. The transfer impedance of a cable is how a lightning pulse gets onto the center conductor of a