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The following photos have been uploaded to the Caaarlo LZ1AQ sweep ( /g/loopantennas/album?id=296346 ) photo album of the [email protected] group. *

This might, or might not, be of interest to group member, and might, or might not, be appropriate to place in the files section. I did a search in my randomly organized archive and found Chris

Hi Siegfried, Checked your design on QRZ. Good design! Modeled it using your dimensions. It gets a great match on 80m with the given height above earth... Did you try using it on 160m with remote or

yes that is an important paper he had FETS where the line was maximum horizontal one way to find the very best FETs via I V statistics over design range he had a great setup to measure a slew of

One of Chris Trask's papers presented curves for several JFETS. I thought I knew where I stashed his papers but I've misfiled them. I'll do a search later, if there is interest, I can post it in the

Fred, I looked for any post from Owen Duffy related to silicone diodes and Hi-Z and or MiniWhip but could not find anything. Can you attach a link? Thanks Tom

Hi Dave, That's what I had done, improved the filtering on the switcher input and output, and screened the actual PSU body to minimise radiated emissions. I swapped them for linear supplies, then

I've used this trick to quieten LM78xx regulators. https://www.quanticwenzel.com/library/time-frequency-articles/finesse-voltage-regulator-noise/ Some LDO regulators are naturally "really low

QUOTE (Martin): Don't assume linear power supplies are noise free. But they're sure quieter than any switcher, UNLESS the money is spent to properly decouple and shield the guts to quiet them down.

At the risk of revealing my ignorance (as if that's a real risk), a lifetime ago I built some moving coil phono cartridge amps using paralleled JFETS. From

Some linear regulators are worse, as I have discovered in trying to use them to power my KiWi websdr's in place of switched mode supplies. The problem is the poor decoupling of the internal voltage

QUOTE: Phase noise and jitter are valid issues, so maybe this is too. I've measured many......many...... canned PLLs and clock oscillators with atrocious noise pedestals! Phase noise, amplitude

That is a useful parameter, and would explain my observations. I wonder if we could use it to equate to a tuned loop with a separate 50 ohm coupling loop, by observing the point at which the Q of the

I'm not sure. My thinking is that if the LF noise "modulates" the received signals, then it may be significant. Phase noise and jitter are valid issues, so maybe this is too. Regards, Martin

But, many times these Zener diodes (a.k.a. noise generators) are used as voltage regulators for LNA discrete devices. There, it matters. However, these days, usually active voltage regulators are

Martin, Here is another piece of information related to a pair of tuned loops regarding their Q-factor. The Q-factor effects the coupling K value between tuned loops when the value becomes a

Martin, In our “business” we would be more interested in RF noise measurements. Don’t we ? Raphael Sent: Friday, July 19, 2024 11:22 AM To: [email protected] Subject:

Some interesting LF audio noise measurements on various devices, including some of our favourites. https://www.mvaudiolabs.com/diy/modern-jfet-noise-measurements/ Regards, Martin

Yes, the Wellbrook input impedance rises with frequency. See the notes on my archived web page, which include Steve's impedance

To avoid misunderstandings, i was referring to reverse biased diodes for ESD and overvoltage protection of e. g. Whip- or other type active antenna amplifiers. regards Fred