SWR Demystified


Excerpt from website…

“SWR, or standing wave ratio, is one of the most misunderstood concepts in amateur radio. One of the reasons for this is that it’s so hard to visualize. I mean, you can’t actually see a standing wave on a piece of coax or ladder line.

Fortunately, mechanical waves work exactly the same as radio waves. That’s what makes this video, titled “Similarities of Wave Behavior,” such a treasure. Developed and narrated in 1959 by J.N. Shive of AT&T Bell Labs, this video uses a specially-developed machine to visually show how mechanical waves work, and because radio and optical waves work in exactly the same way, you’ll also learn how radio waves work.”

How to capture NOAA Weather Satellites transmissions


Really interesting read, especially for us hams that are also weather nuts! I plan on trying this expierment myself very soon.

Excerpt from the website:

“Most people are aware that every day weather satellites pass overhead to get a glimpse of the nation’s weather patterns. Many people, especially those outside the ham radio community, are unaware that the signals these NOAA weather satellites transmit are readily accessible with a minimum amount of equipment….”

“All you really need to receive the satellite’s signal is a radio receiver like an old police scanner (found at thrift stores) or a simple 2m ham radio handitalkie. An external antenna is usually better, but not a requirement for casual reception of the image. Other than the radio, the only other pieces are a computer with sound input and an audio cable (to get the audio out from the radio to the input on the computer)…”

” the NOAA 19 satellite transmits at 137.100 MHz, so it is vitally important that your radio be capable of tuning this frequency. It is also important that the radio selected for this project be capable of “Wide FM” and not the “Narrow FM” used for amateur and commercial radio services. APT Satellite signals are 34kHz wide, which is wider than the 6kHz and 15kHz of Narrow FM. Wide FM is most commonly used for FM Broadcast stations which are very wide at 230kHz. Ideally, the radio chosen will have the ability to filter somewhere in between these extremes – wider than Narrow but narrower than Wide…”

Check it out!