At the Chelsea Amateur Radio Club sponsored electromagnetics training series, we are learning about the Smith Chart as a tool towards upgrading our amateur radio licenses with the FCC.
We have found a product that fits in the palm of your hand called the “RF Demo Kit.” This board has various RF circuit fundamentals that can be used in a laboratory environment to learn of those aspects of electromagnetics. These aspects of electromagnetics are front-and-center in FCC amateur radio license upgrading. You can just memorize the questions and answers to pass the exams. There is certainly value in that. However, everybody knows you will forget 90% of those questions by next week. Wouldn’t it be better to take longer to prepare for the exam but understand what the questions are all about? Further, the reader is asked to recognize that having this electromagnetics knowledge, he or she will then be able to move on to innovation.
Here is a list of what you will need for this video conference laboratory class. We are going to show suppliers as well but these products are available from a variety of sources. We are not explicitly recommending these suppliers but it appears to us that they are valid choices. If you do pick your own supplier, verify that the board will come with two compatible patch cords.
- A RF Demo Kit Test Board Vector Network Rev-01-10
Note that there are other revisions out there. It would be most helpful if you would be careful to get this particular revison.
- Obtain from AliExpress
- DX Engineering — But this is a different version
- A combo package containing both an RF Demo Kit and nanoVNA
- A Pocket Knife
You don’t need anything fancy. Any pocket knives, no matter how miniature, will do the job. A pocket knife makes the disconnection of these IEXP connectors incredibly simple.
- Patch cords — These enable a daisy-chain
The two cables that come with the Demo Board are IPEX to SMA. This enables connecting any of the Demo Board ports to the nanoVNA. With supplemental male-to-male patch cords you can daisy chain elements of the demo board.
- AliExpress— IPEX Male to Male patch cord that is at least about 4″ long. These are apparently in little demand so they are hard to find. See an alternative below.
- Male-to-Male IPEX splitter
This may find use in developing creative configurations.
- An alternative to the hard-to-find IPEX male-to-male is a close relative of the cables supplied with the RF Demo Board. But also order some gender changers so that they can mate up with what you have.
- SMA to IPX Coax SMA Male Plug to UFL IPX IPEX Cable–Needs a gender changer
- IPEX/MHF1 to SMA Female Coaxial Pigtail Jumper Cable
This one will enable you to one of the supplied cables for daisy chaining. No gender changer is needed.
- Here are some websites for information
- Here is a website where U.FL Series connectors are explained in great detail.
- Hangzhou–This website uses a different revision board but the info is very good.
- nanoVNA Applications
- This page seems to have a lot of good info but all of the illustrations are blank.
- Characterizing the RF Demo Kit — Avian’s Blog
We recommend that you buy two (2) of the demo boards because those ultra mini IPEX connectors are as fragile as hell. When you are connecting and re-connecting numerous times, the odds are something will go wrong. At least when you have a successful connection with these connectors, you will feel and hear a distinctive snap giving you confirming feedback of the successful connection. But once one of these connectors is securely mated, it is good to go and is relatively safe from being damaged. Problems result when they are haphazardly removed or connected.
Here is a website that explains what the RF Demo Kit is all about. The website also includes a quick start guide but this is only of use as a cheat sheet once you start using the device. It also shows a sample of test operations that you can do with the board. However, the instructions on this page are somewhat cryptic and have a lot of Chinese.
We also found a website that explores the nature of the RD Demo Kit.
Here is a 20-minute informative video that give a nice intro to the use of the board.