Waterfall Displays Explained: Ask Dave #21

The Ask Dave series answers your questions about ham radio, with emphasis on those of interest to those new to the hobby. This video explores various types of "waterfall" displays. My channel, Ham Radio Answers, also includes training videos for the Tech, General, and Amateur Extra examinations. Please subscribe!

[BrightBlueJim]

Fun fact: waterfall displays were introduced in military RADAR systems as well as SONAR. My involvement was with the system implemented on the AN/FPS-26A system that the US Air Force used, which was introduced in 1962, but this was not by any means the earliest implementation. In our system, because our scopes were not digital, so they could not move the historic data. Instead, they scanned slowly from the top to the bottom of a CRT that had a very long persistence phosphor, so that you could see the last minute or so of activity on your band, before returning to the top of the screen. But aside from that difference, it looked very similar to today's SDR waterfall displays. The band for this system was 5400-5900 MHz. It was used for evaluating what types of jamming devices were being used against your station, as a tool to determine the best countermeasures to apply, as different receivers had different efficacy against different types of jamming, and we had several receivers to choose from. I didn't work with any naval equipment, but Destin at "Smarter Every Day" has a recent video about how waterfall displays are used on submarines. Totally different beast, there.

[greghawkins]

Dear Facie, thank you for explaining this subject to us. You're a true professor of electromagnetic energy. With radio, we can speak & hear farther than our voices can carry & our ears can hear. In cowboy tines, this would've been seen as magic.

[amudlifecrisis]

Another great video Dave, thanks for sharing. I learn things I didn't even know I would like to know about when I watch your videos.

[nokomisjeff]

My starving millennial son (KI4QOG) turned me on to your series. You do a wonderful job of explaining everything for the newbie, and I will recommend it to a couple of kids that I'm Elmering. 73 de W9NYX

[JerryWick]

The ducks and their speech bubbles coming down the waterfall literally had me quacking up

[nickt]

Thank you Dave. Great videos which are perfect for this newbie.

[doxasnob]

Thank you Dave, I understand, I understand!

[Manoj-mydj]

Thank you, you explain it in a very easy manner.

[JDs_RandomHandle]

So I was looking for sonar systems but this was extremely helpful, I'm assuming that this applies to sonar as well.
Funny enough I started getting into radio recently and didn't know that this was a possibility with radio, makes me want this COVID-19 to end so I can take my tests

[terrymishler]

Dave my wife and I each bought a YAESU FT2D followed by taking the Technician exam. We passed and are waiting for published notification. This information you provided is exceptionally accomplished but yet a little confusing for two 71 year old retirees. We're studying for General now and really look forward to becoming proficient with these radios for we travel in our RV full time. We bought radios because of the seriousness of being able to request help and to help others. Two radios because we are sometimes separated for a week or more when Ruth flys home to visit our two wonderful granddaughters. I request please the necessary (in your opinion) additional equipment you recommend enabling us to become (as we hope) "professional" amatures one day. We cannot express our warm thoughts to you for sharing the great informations and look forward to viewing more of you're videos in the near future. Again, thanks so much. Terry and Ruth Mishler

[tpmbe]

Excellent many thanks for the information... Great ! good to have all our ducks in a row !

[nofxslc]

Thanks again for the great content and QSO on 40M LSB! Great making contact with you.

[johnlaurin]

Dave: I like the rose to ham radio analogy. Nice pictures. Thanks for all that you do for ham radio. KG7SHC

[bladeguy]

Just heard you on 14.278, could not make a contact the band died. First celebrity sighting on the bands.  Thanks for all you do. 73 de KM4OVT, Steve

[kerrym]

Great explanation, that helped a lot! 73, KC0MDO

[adelarsen]

I like operating low power portable next to a water fall out in the nature :-)

[tonbonthemon]

Noob question: it looks like at 6:30, you're receiving text messages through radio? Or is this transcribing something someone said? I'm using a ham radio app on my phone just to listen in and sometimes I find activity that doesn't sound like voice or even morse code... just a bunch of weird sounds and I'm wondering if it could be a different means of sending data.

[samiam]

No umbrella needed! I want santa to bring me a SDR swl rig w/waterfall display, the many affordable rigs available now. Any advice on which one is best for the buck?

[rcx]

FiFi SDR looks interesting but very little on Google about it. It is discontinued?

[laurentgudel]

Thanks for the video! I try to create high quality images from a waterfall display. How could I do that? Is there any software with "high resolution" waterfall?

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