Total common mode inductance is 1 times L, not two times L. This is because the windings are parallel with near infinite mutual coupling. It is exactly like a bifilar filament choke. The 2200pF caps
Here is the tough time with this, because I'm sure most people take device manufacturer's data at surface value. All of this stuff, to this point of time, is mostly vaporware. Here are the worries:
Hi Bruce, I'm sure Harris did a great job. The modules can be swapped while the TX is on, even power supply modules, which is a nice feature. But hot or live swapping does not mean the modules are "h
Right. My point is people seem to be reading the data sheet for the device, which is a very confusing data sheet. The data sheet, if read carefully, is for class-C pulsed duty with (I think) 20% dut
I've never experienced this before a year or so ago, when I had a Beverage antenna melt in two from a nearby tree getting hit. About a month ago I had about 300 feet of a Beverage just vanish from a
Hi Larry, All of the links and data agree with what I found here in my measurements. I think the real issue is some very creative marketing is being done, and the factory data sheets can be a bit con
No, it was lightning. Here are pictures from an earlier event: http://www.w8ji.com/lightning_strikes.htm Now the problem is making wires vanish for long lengths, hundreds of feet!!! This problem see
The statement CATV coaxial cables or cables with foil/drain shields do not have good shielding, because of transfer impedance and high resistance, was made a while ago here on this reflector. I think
I can easily and quickly test any 8 foot length Mike. I just added a scrap from my old Dish network system that blew off the roof last week. _______________________________________________ UR RST IS
I can put a number on that using two-year old indoor-use ComScope "Brite wire" ( I think that is what it said), which is a non-flooded dual shield (foil and braid). 160 -80 dB 80 -88 dB 40 -99 dB I
I can't actually measure it Dave. I have a spare port on my test fixture that is identical to the sample port. When I swap my voltmeter over to that port and run 1 amp of RF current on the tested ca
Unfortunately that can lead to a waste of time and material, and even has some bad advice. Common mode chokes NEVER belong between transmitting device like a radio and an amplifier, or between thing
Carl, Regardless of what feelings people might have, beads and isolators really do not belong on transmitter lines between amplifiers and radios, or between filters and amplifiers. There isn't any re
Hi Victor, Beads and common mode chokes only modify common mode impedance on the outside of cable shield. They do this by allowing a voltage difference to appear across the bead or choke. This means
Hi Carl, It is much more than experience. Good science can be proven or illustrated through experiments and measurements. Opinions are just opinions, and have the same value as the effort that went i
It seems Frank, Jim, myself, and many others are in exact agreement. This is because underlying science is universally logical and valid, and proven both by measurements and by time in thousands of
Grounding of equipment on the desk has nothing to do with TVI or RFI, unless you have terrible antenna common mode or other cable issues bringing RF into the shack, or cable or connector issues in t
That's exactly what I do periodically when the connectors lose tension. I also use CM chokes (beads) near connectors in case they develop a little bit of resistance. Overall, I have few problems. If
Shielding and grounding is probably the least known art, as are audio line source and load impedances. I had problems with my K3 when I pointed my Yagi's at the house. As a quick fix, I cut into my
Hi Peter, To which you replied: What everyone should always remember is if we block HF current from a coaxial line to intentionally float a chassis, we elevate the voltage swing of the chassis. This