Because it's much more fun than using the same old wheel every time!

I would like to emphasize on the point Jim made: As long as you have an USB cable running into the antenna's near field, it will affect the measurement, even if an USB isolator or an RF isolation tran

Oops! Those who might want it, get it while you can - or else you will have to ask the Wayback Machine. More and more creators of well-known software are retiring. Many of them go the extra mile when

A basic PC sound interface is simply a group of analog-digital and digital-analog converters. They operate at least in 16 bit resolution, while many have 24 bits. The sample rate is settable, at least

Since the NanoVNA covers from 10kHz up, one can use the sound system of a PC with suitable software to provide the lower frequency coverage. Even the most basic sound chip in a PC will cover 20Hz to 2

For the proper operation of a transmitting antenna system, there are just three main points: 1. The antenna+feedline system needs to present the proper load impedance to the transmitter. In most cases

Warren, and all, I fully agree on this point: I just made the test. I selected two toroids of identical dimensions but totally different materials. One is a Ferronics 11-260-K, the other a Ferronics 1

Instead of becoming partisan against or in favor of stacking toroids made of different materials, it's better to look at the underlying physics. Stacking two toroids, and winding a certain number of t

Hi Ken, just reading the group digests of the last two weeks, I got amused by the many replies which do NOT really answer your questions! Instead of measuring common-mode S21, I would prefer measuring

Neil, What I can glance from your measurements is that the impedance of your parallel transmission line is incorrect (too high). To fix this, I suggest winding with coax cable instead of that pair of

Yes, one can very well use SMD parts in 3D, dead-bug construction style. I have attached a photo of a buffer amplifier for digimodes that I added to the underside of a board in my Kenwood TS-450SAT. I

I'm also using that building style quite a lot. Attached is a look under the chassis of my 15-band MW/SW AM radio, and also a photo of the FM module that I will add to it, to turn it into a 16-band ra

Jim, Good that you mention this. I suspected that exactly this is the origin of the excessively good RF reputation of composition resistors, but never before saw anyone clearly spelling it! Yes. Today

Zack, I have never seen why some textbooks consider composition resistors to be better for RF than film types. I cannot confirm that, neither from practical experience nor from measurement. Rather to

Mikek, I think that you are chasing a phantom there. I will try to help you disprove this! My first point: If such a drastic reduction of inductance at very low drive levels was real, then ferrite-cor

A trap is simply a resonant circuit. You can measure it like any resonant circuit. But since traps are build to handle significant power, they are usually somewhat large, which makes them more sensiti

My experience with having small orders shipped from the US to Chile by mail, since about 1980 until nowadays, is like this: In the beginning, there was airmail and surface mail. Airmail arrived quickl

That's also why I stopped ordering from the US. At least RandL is willing to ship by mail! Many, if not most US companies, refuse to ship by mail, and only give a choice between DHL, UPS and FedEx, wi

I placed a lot of orders on AliExpress over several years, including the NanoVNA, TinySA, etc. Most of the time it worked fine. Until recently! AliExpress sent my last three orders through a little ba

Interestingly I cannot confirm that coax cable necessarily degrades over time! Of course, if cable gets waterlogged, it will degrade. But properly used, which means avoiding water ingress, it can last