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Hi Martin, Well when you have a separate 50 ohms coupling loop ( your excitation loop ) coupled with a tuned loop: 1. More separation betveen both loops - lower the magnetic coupling K coefficient,

Steve, Thanks for doing this. It would be a shame to lose these designs now that Andy is gone. I added a folder and two files illustrating

I'd like to see that Russian verswion. Could you forward it? Chris When the going gets weird, the weird turn pro - Hunter S. Thompson

First, disconnect the anttena, Is the red light on?? My antenna interface is like yours, has a resettable fuse too. Ckeck your power supply, and check the interface output with a voltmeter

I will repeat Chavdar's commercial email address (he produces the amplifier and interface board under the active-antenna.eu brand name) as before. Use the for or following

Hi Todd, Measure the DC current being drawn by the loop amplifier, somewhere along the coax feeding the loop. This will determine that power is actually reaching the amplifier, and if the devices

Hello all, I am trying to troubleshoot an issue with a used Wellbrook antenna.? When I set it up the day before yesterday, it was working very well!? Then today I noticed a problem with an

Some additional power supply notes. I mentioned there is a severe problem in the way most circuit designs for the uA723 have an error. I said I thought 100 ohms was needed in series with the current

There is no email address on the site for Chavdar Sent: Saturday, July 20, 2024 1:58 PM To: [email protected] Subject: Re: [loopantennas] LZ1AQ Purchase Control Board Only Send an email

Send an email to Chavdar. For additional info please use the for or following address: info(AT)active-antenna.eu https://active-antenna.eu/about-us/

As I told Steve, someday soon I hope to collect all the Trask papers I've got stashed on several hard drives into one subdirectory. I believe Mr. Trask has several papers on loop antennas. "Someday

We misplaced the small Control Board for our LZ1AQ. Does anyone know how to purchase it only without the whole kit or how to contact the manufacturer to buy replacement? Thanks

I recently discovered the TI JFE2140 dual JFET: https://www.ti.com/lit/ds/symlink/jfe2140.pdf?ts=1721435629268 0.9 nV/sqrtHz noise and 100 Hz 3dB 1/f dB corner There is an excellent ap

I found this in my saved documents on my PC. The weblinks on the net no longer work, but I did find a? MS Word version in Russian. Regards, Ian.

I've posted JFET Evaluation for active antennas Trask in the files section. A very nice paper on various JFET response. While the paper is for E-Field antennas, the data is valid for any JFET

Go right ahead. Chris When the going gets weird, the weird turn pro - Hunter S. Thompson

Paralleling multiple devices to lower noise is not unique to audio. There are similar prior arts at RF & microwave too (see below). Amplifier for FM antennas - Patent

I linked the Duffy article in post#19752 ( /g/loopantennas/message/19752 ). The section at the end of that article is sub-titled " *Diodes connected to antennas* " 73, Chin-Leong Lim,

The transformer is 4:1 turns ratio.... 16:1 impedance ratio.

Update: Added Chebyshev 3-8 MHz 3rd Order BPF, and also replaced the 1uF input caps by 100nF ones as they resulted in a flatter response between 3-4MHz and improved MF