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We were discussing batteries a few weeks ago and I mentioned I used high value capacitors, AKA super capacitors, to replace the 3V lithium disk cell. I received an email asking for details. All of

I ran into a problem Monday, time for the first lawn cutting of the year, trust me, at 73 I don't even use a riding mower because the vibration would kill my artificial knees, our landlords are a set

Pull out your analog design books. This is a feedback loop.? The two NPN transistors are a differential pair.? ?I trust you know how differential pairs work.? The difference voltage between the

Hello, I am trying to understand the dinamics of the circuit taken from the youtube video. if we apply 2V DC the node 2 on the photo will be 1.4 (Vbe=0.6) The node 1 will expirience some voltage wich

On Fri, Feb 28, 2025 at 11:35 AM, wn4isx wrote this about motorcycles: I have a theory about that.? Drivers instinctively use the space between oncoming headlights to gauge how far away it is.?

This is just a question about the question you asked, as I am unable to provide information about plans for a differential temperature regulator - I am unsure how to interpret "1Kelvin". Do you mean

Hello, I am looking for a differential feedback temprature regulator project which explains the theory best it could and give practical example in simulation. I am looking to design a very precise

Another extensive active antenna link! Thanks! More reading ? Time allowing, I will build something. Right now, I got to take care of business as a priority so getting something that reasonably

While I learned the required subject mator for my two degrees in university, the main thing I learned in university was how to research. It was a bit of a challenge to transition to the web but well

Thank you wn4isx! Your link to Martin G8JNJ's active antenna pdf very extensive: https://qsl.net/l/lw7dfm/Antenas/Antena%20Mini%20Whip/MARTIN%20-%20G8JNJ%20- %20Active%20antennas.pdf More

I found that one, https://www.pa3fwm.nl/projects/miniwhip/, but I have not found the second part one in the pictures that is discussed with improvements. I found this one that looks

After spending too much time searching and reading about active antennas and building a library, I visited Amazon. Search for "Mini-Whip Antenna". There are enclosed ones, but I ordered a promising

Pieter-Tjerk de Boer, PA3FWM has a series of articles on E-Field antennas that can be extremely helpful in getting the best performance from these antennas. Fundamentals of the MiniWhip

Pedid y recibiréis Simple and better circuit for MiniWhip antennas https://www.pa3fwm.nl/projects/miniwhip/ The 2SC5551A might be a viable substitute for the 2N5109 in the original PA0RDT

Thanks, I have no specific plans except testing the new technology and also look at GPS signals. I did a lot of work with GPS 30 years ago and I still have some active GPS antennas to try. The

Previously wn4isx posted a link to: https://www.pa3fwm.nl/projects/miniwhip/ The reference refers to an improved version but there is no link to it. Does anyone know where I can find the improved

What do you want to listen to? I might be able to offer some advice.

As I mentioned, I have one main program that was extremely expensive, cost me over $1000, I also routinely use Adobe Audition, while there are good audio programs for Linux like Audacity, they are not

Yes but I'd be forced to learn to use an Ardino, build a case, etc, the Dataq requies a USB cable and is ready to go, time saved at my age is well worth a few dollars.

Thanks for the introduction of SDRplay. I used to design commercial RF equipment but not for the last couple of decades. So I decided to buy the SDRply RSPdx-R2. Now I have to review the antenna