1. See the recent TowerTalk thread on electric fences. :-) 2. Put the cable in conduit/pipe. A master electrician with decades of experience with buried cables recently told me that PVC conduit keeps
The questions you asked are so broad that it'd take a big textbook to answer them, and AFAIK the book you would need does not exist. I think that your only hope is to post a very specific question, a
I'd live with the mismatch, which seems trivial. Parallel two 75-ohm lines to cut your loss further, if 38-ohm line would suit you better. -Chuck, W1HIS
An astute Towertalk reader asked me off-list whether the ferrite that I had salvaged from my burned-out common-mode choke/balun was still good. He said he had read that frying ferrite ruins it. I rep
You are absolutely correct, and I knew it when I wrote what I did, which is why I hedged by writing that they do not retain **much** magnetism (in comparison with "hard" ferrites). I probably should
Someone mentioned that he had discarded the pieces of a ferrite toroid that had broken in half (due to overheating); I suggested "glu[ing] them back together, using rubber bands to clamp them tightly
The large number of Towertalk posts relating to ferrite-core common-mode chokes, baluns, and transformers (which often are different names for the same thing) says that this is a mainstream topic. Ev
Start with common-mode RF chokes on your RF transmission line, both at the antenna end and at the transceiver end. See below for details. Also put RF chokes on all other cables connected to your tran
Yes, very much so! An antenna (or part of an antenna, such as one-half of a dipole connected to the center-conductor of a coaxial feedline) left floating very easily acquires a (literally) staggering
On armyradios today, from <Jim-M1-Radio@attbi.com>: NE, waterfront, mild wind (maybe 10 mph, snowing, mid 20's, very dry air, 150 foot long wire, #6 AWG: When disconnected from radio or ground, the s
I have two RadioWorks type T-4 line isolators, both of which overheated while I was transmitting 1.5 kW. One caught fire. Dissection revealed that they were wound with 0.2-inch (o.d.) coaxial cable a
Lately, every time I post a message to TowerTalk, I get back a couple of "nondelivery" error messages like the following one, relating to <steve@netmakers.com>. Am I the only TT subscriber getting th
About three years ago, suckered by RadioWorks' advertising which seemed to say that the common-mode-choking impedance of their so-called line isolator at 3.5 MHz was _extremely_ high, of the order of
I'm having difficulty thinking of fields of human endeavor outside ham radio, where actual product performance is more substantially and consistently worse than advertised. So far I've been able to t
I agree. Since the main purpose of a tuner is to accommodate mismatch, the advertised power ratings of tuners should logically include statements of the load impedances and frequencies for which the
This wonderfully convenient method doesn't work for hams who live near AM broadcast antennas. The definition of "near" depends on a bunch of factors, obviously; but I can tell you that the 10-kW 1150
Here's how to determine when your C-L-C T-network antenna tuner's output capacitor (or if you choose, its input capacitor), is fully meshed -- without opening the box. You need a multimeter (like my