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Hi Jim, Thanks for referencing my paper. :-) However, I will not recommend that limiter configuration for protecting the Rx loop. The described Schottky assisted PIN limiter has a ~10 dB lower turn-on

Interesting question. There are interesting amateur tests of the 1N4007/1N5408 as replacements for the Unitrode P-I-N characterised diodes. At least one experiment shows that 1N5408's were lower

Hi Fred, I agree with the points you are raising, with some caveats. In a 50 ohm system, a pair of 1N4148's or similar small signal silicon diodes will limit at somewhere around +10dBm, and second

Icom uses a pair of 1SS302's to help protect the FE of the IC-R75 receiver. They are very fast & I use them in a protection circuit I built for my receivers downstairs in the torture chamber (repair

It is a common misconception that there is a sharp forward voltage threshold for diodes and that there is no current flow below this "forward voltage". A diode is an amplitude-dependent, non-linear

It depends. With an E-field active antenna a single 1N4148 can generate significant IM products. In this case it is better to use stacked silicon diodes or reverse biased silicon diodes. Another

Are we maybe overthinking this ? A pair of back to back 1N4148's or a BAV99 should be perfectly adequate in a receive situation. I use a pair of 1N4148's across the antenna cable from my "old

Hi Andrew, The 1N4148 ist a fast switching Diode. Some 1N4007 have a long carrier lifetime and behave like a HF PIN Diode. regards, Fred

Hi Jim, I wonder if a 1n4148 and a 1n4007 would work in the same way for HF? Andrew VK5CV Get Outlook for iOS<https://aka.ms/o0ukef> ________________________________ Sent: Thursday, 27 February 2025

Jim, thank you. It's always easier to follow a diagram. Much appreciatedAdam Yahoo Mail: Search, organise, conquer On Thu, 27 Feb 2025 at 3:13, James Redding WA9VEZ via

It will be informative to follow the link below: https://www.researchgate.net/figure/Details-of-the-PIN-diode-construction-top-right-the-limiter-assembly-top-left-and_fig1_271463118 Have a nice

Hi Fred, If I recall, it was an experiment I tried after reading about *tuned* spiral loops (windings in the same plane) in the early days of radio. My intented use was MW only, and I was seeking a

Hi Guy, why did you choose a spiral-loop? The enclosed loop area is a key figure of merit of a small magnetic broadband loop. With a spiral loop the enclosed loop area decreases with each

I've agonised over azimuth sensing - been looking for a battery-powered device with built-in Wi-Fi or Bluetooth sender and a PC Windows receiver that "exposes" the azimuth value for easy capture by a

I have that exact rotator. It is fine for a 1 to 1.5m diameter loop. Although the readout only indicates 10 degree steps, it can be "jogged" to any position allowing good nulls if necessary. Tom

There is a re-calibration sequence in the manual if it get out of whack, but I'm not sure if it covers that situation.

Oops, this 3rd link is the one for photos of the spiral loop on rotor: https://photos.app.goo.gl/tNcv3Dqn3QB4MTqt7 -Guy

I did something similar in 2008. One design was a small bidirectional loop on a rotor, and the other was a four-turn spiral loop on a rotor. Both used Wellbrook ALA100 modules. Support elements in one

The shape isn't critical. Att that matters is loop area (length x height). Bigger area, more gain. /Hans

The SULA is a smaller loop than most FLAG antennas but both bigger than a YouLoop Regardless they are interesting to experiment with and can use a preamplifier The County Wireless loop amp is a