On Nov 30, 10:30 am, "Tom Donaly" wrote:
K7ITM wrote:
On Nov 29, 9:11 am, Jim Kelley wrote:
...
Over the range of a few octaves, propagation delay on the other hand
does not vary to any significant extent as a function of frequency.
Ostensibly, it should be equal to sqrt(LC) series L, shunt C.

Actually, Jim, I do expect it to have considerable frequency
dependence. I think you can find info about this in books that
address the design of travelling-wave tubes.

But...one must be very careful about describing exactly the experiment
or the conditions around a particular scenario. That's why I don't
have much interest in getting involved in this "discussion": it could
well be that much of the difference among all the claims and counter-
claims could be trivially resolved through better communication.

Cheers,
Tom

I don't think they're writing about real transmission lines, Tom. If
they were doing that, there would be no discussion because then it would
be too hard to understand.
73,
Tom Donaly, KA6RUH

;-) Yeah, I know what (they think) they are writing about; I'm
writing about coils more-or-less in open air, which should match
pretty well with the current discussion. But again, as with so many
of the discussions here, it's not worth getting tangled up in. I just
thought it bears mentioning that there are some coil models available
out there that go beyond simple inductance. Inductors are among the
least ideal components I deal with, and having models that address the
discrepancies has been helpful to me in practical designs. If people
want to argue, rant, get red in the face, ... about how something
works, more power to them, but I've got some designs to work out and
I'd rather be spending time on them. (How small can I make a 1MHz
bandpass filter that has less than a couple dB passband attenuation,
more than 120dB attenuation on 2MHz and 3MHz, and shows distortion
below -140dBc for inputs up to half a watt or so...??)

Cheers,
Tom