How has the N8VB FEP circuit I posted earlier performed in HF contest stations with kilowatt transmitters nearby?
"How" is the question I hoped you might be able to answer.
If he only thinks one bulb has burned out in many years of operation, does it look they work as as a fuse?
There's no mention of diodes ever being fried, does that mean diodes alone are good enough?
Or, do the diodes conduct long enough for the globe to provide 40 ohms resistance without blowing out and can just 40 ohms save the day?
"The Kiwi itself uses TVS diodes across the RF/HF inputs"
"We have not done any limit testing of the inputs"
TVS diodes are designed for the job, from Wikipedia"
"...made and tested to handle very large peak currents. The 1.5KE series allows 1500 W of peak power, for a short time."
Perhaps the Kiwi's built in TVS diodes alone save them and it had nothing to do with any external circuitry?
Perhaps it was both? Perhaps it was a lucky combination of the antenna spacing, the resonant length of the feed lines and the frequencies in use?
Regarding your second link, the FEP, don't you find a credibility problem with the article?
He says his 100 watts test blew the globe and in the same breath he says he's happily transmitting quote "a full 100 watts on CW"!!
Anyway his tests relate only to his own antenna, feed line and frequencies in use.
Any nasty incoming signal voltages and currents at his receiver will swing between current maximum/voltage minimum and current minimum/voltage maximum every 1/4 wavelength of feed line and antenna at the respective frequency. Just like the voltages at the ends of a centre fed resonant dipole that can typically be in the order of 6,000 volts.
ref: https://ham.stackexchange.com/questions ... le-antenna
His test failed to take into account the protection his radio already has built in, perhaps the clamping devices in his radio are what blew the globe.
Herein is my problem, restated for clarity
1. Globe filaments and gas discharge devices "do not exist" during their slow turn on time. None of my commercial radios have them in them. Are there any commercial devices being offered to the ham market that use them? So, do they make a difference and if so how? I have no answer.
2. Diodes are widely used, with the right combination of resistance and capacitance may be that is all that is required. They've worked fine for me so far but I take care by switching my SDR line's coax switch when I'm using the 6m beam, for example. That's a pain and why I'm trying to find a better solution.
Best hopes this discussion is entertaining someone
73 Phil VK7JJ