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Received signal patterns - waterfall

KC8PKC8P Member ✭✭
edited June 23 in SmartSDR for Windows
I was wondering if anyone could explain why I see these patterns on received signals.

One of my friends switched between 3 different rigs and the specific pattern persist....quite strange.

image


image

Thanks
Mario
KC8P

 
«1

Answers

  • K0UNXK0UNX Member
    edited June 2016
    Hmmm.  3 different rigs, but same pattern.  Antenna related?  Maybe he needs a COMMON MODE CHOKE at the ANTENNA feed point?
  • Walt - KZ1FWalt - KZ1F Member
    edited June 23
    I don't know that this will directly answer your question but I've seen whole words spelled out in the waterfall. One would never tell that from the spectrum display but clearly in the waterfall there were words. In the top waterfall above, it does look like something of a video interference pattern.
  • K5CGK5CG Danny Member ✭✭
    edited December 2016
    I've seen callsigns in the waterfall from a Hybrid SSTV application called EasyPal see this post https://community.flexradio.com/flexradio/topics/how-does-one-get-their-callsign-to-appear-in-the-waterfall
  • Duane_AC5AADuane_AC5AA Member ✭✭
    edited May 2018
    How do other people's signals look?
  • K5CGK5CG Danny Member ✭✭
    edited December 2016
    Here's one I captured a couple of weeks ago.
    image
  • K0UNXK0UNX Member
    edited June 2016
    Looking at his first graphic, I see two other signals that don't have that cross-hatch problem.  That station probably has a lot of noise on that antenna as well.  The graphic below shows me switching antennas on the same frequency.  The TOP antenna has a LOT of signals every 10 KC and NOISE.  The other antennas don't see any of that.  I have a common mode filter on order to cure that one antenna.  image
  • KC8PKC8P Member ✭✭
    edited January 2019
    Ok, I see this mostly on 80m, random stations, random patterns......a few minutes ago:

    image
  • K0UNXK0UNX Member
    edited June 2016
    If you have another antenna, even for a different band, whether those patterns will disappear.  If so, then the antenna is introducing them, just like my one 15M antenna is doing.

  • KC8PKC8P Member ✭✭
    edited January 7
    Forgot to mention, I've tried 3 different antennas, inverted V, vertical and K9AY.....same pattern....
  • Wheelin RevWheelin Rev Member
    edited August 2017
    Here are some webpages to get you started with signal identification:

    http://hfradio.org.uk/html/digital_modes.html

    http://www.kb9ukd.com/digital/

    http://www.sigidwiki.com/wiki/Category:Amateur_Radio

    http://wb8nut.com/digital/

    And to the poster that said he saw letters, yes, I have seen that too as well as images. You were not imagining things...

    73, Dave K4EET
  • Ross - K9COXRoss - K9COX Member ✭✭
    edited June 2017
    Phone home
  • pa0biepa0bie Member
    edited March 2016
    This is the right answer. I have this always on 80m dependant on the distance to the other station whe we are working with FreeDV.
  • Jim  KJ3PJim KJ3P Member ✭✭
    edited December 2016
    I agree that this is the correct answer.  I have seen the phenomenon when the "ripples" were deep and slow, and heard the phasing effects in the audio.
  • Martin AA6EMartin AA6E Member ✭✭
    edited January 20
    The patterns are a propagation effect.  The patterns you get depend a lot on which band you're on (higher bands generally show less effect) and the propagation distance (more effect the farther away you are).  They show up most clearly when you're looking at a broad, flat spectrum digital signal like digital voice.

    Technically, the ionosphere's electrons (which reflect RF and enable long distance skip) have density irregularities -- they are more or less bunched up in "clouds", and each cloud acts as a separate reflector.   The pattern you see represents "beats" (interference) between the different reflection paths. It changes with time because the clouds are moving around. You can call it "multipath interference", "selective fading" or "scintillation". 

    Stars twinkle, too!  (But not because of the ionosphere.)
  • Mark_WS7MMark_WS7M Member ✭✭
    edited March 2016
    I think this is part of my fascination with SDR is that I never before had a radio that could even display a pan, not to mention a waterfall.  The add-on's for those were expensive.

    When I look at various bands I see all kinds of stuff going on.  Some is easily recognizable as a human signal other stuff is man-made noise and then there is this other stuff that dances around, perhaps runs up and down the band.

    I'm sure it existed when I had my old Kenwood and all the radios before that.  I could just never see it.  I do remember what I used to call "birdies" when I would tune my radio and suddenly hear this constant whistle.  I could never figure out if the radio caused them or something else.  Now I can see them!

    We humans for the most part are visual beings.   Being able to see a representation of our RF spectrum has made radio even more fun for me.  I'm not transmitting as much and in fact I get great pleasure out of watching the wave forms of other transmissions.

    I still have noise to find/hunt for and hopefully eliminate.  It is new this winter.  I didn't see it in summer. That massive peak just below 14.010 will move.  Most of the time it sits right on 14.030 and as you can see there is some activity there right now that when the peak is in place over that frequency is just hidden.

    So I'm finding having SDR to be fascinating to look at all these displays and signals.

    image
  • Ross - K9COXRoss - K9COX Member ✭✭
    edited June 23
    I've been staring at the SDR displays for over 10 years now and really can't imagine ham radio any other way...honestly.
  • Tim - W4TMETim - W4TME Administrator, FlexRadio Employee admin
    edited December 2016
    Ditto.
  • K5CGK5CG Danny Member ✭✭
    edited December 2016
    I'm a newbie and I already believe I could never go back to a dial and an S-meter alone. I would feel totally blind. So... Ditto also.
  • Steve K9ZWSteve K9ZW Member ✭✭✭
    edited November 2016

    There is something neat about firing up a vintage radio and doing it the "hard way" too.  I'm finding a bit of time with a oldtimer, paper logging and nothing digital running to be relaxing. 

    But as I say that I would not want to be without the feature set of the Flex-6000/SmartSDR as a main radio.

    73

    Steve K9ZW

  • Ross - K9COXRoss - K9COX Member ✭✭
    edited March 2016
    One side of my shack is SDR's and the other side is HQ-170, SX-117, Jonson Ranger II, SB-101 as built in 1967, etc.
  • Peter K1PGVPeter K1PGV Member ✭✭
    edited December 2016
    You can transmit a pattern that causes the waterfall to show your callsign or the mode that you're using with fldigi... the mode thing can be cute if you're using an obscure mode.  I don't use it, personally, but I see how it might be useful.  I guess.

    Peter
    K1PGV

  • Peter K1PGVPeter K1PGV Member ✭✭
    edited December 2016
    I've been staring at the SDR displays for over 10 years now and really can't imagine ham radio any other way...honestly.
    No joke.

    I was first licensed 10 years ago (OK, so I'm a late bloomer).  After a very brief stint with a couple of Kenwood rigs, I got an SDR-1000.  It's was the first HF radio I did any serious HF with.

    After that is was a 1500 and now I've been using a 6500 for a while.

    While I've been a SWL for many years, and I theoretically understand how to play (HF) radio with a dial, I have never done so without using a panadapter.  It's all I've ever really used, and it's all I know how to use. It's kind of... embarrassing, really.  I'm pretty much lost when I can't see the band to pick out a station or an opening.

    True story: I remember visiting W1AW a few years back.  They offered to let me operate for a while.  I had to decline... because all they had were radios with knobs!

    Peter
    K1PGV
  • Mark_WS7MMark_WS7M Member ✭✭
    edited March 2016
    Peter, we all have to start some time.

    I started radio in the early 1970's.  I had a crystal 25w CW transmitter and I spent a month trying to build a receiver but I kept blowing things up so my Dad got me a Kenwood R599.  Great receiver but dials only of course.

    I had 3 crystals and I'd tune to my crystal freq and if in use I'd wait.  Meanwhile I'd tune up/down and I heard all these things but never had a clue what they looked like.

    I've been through about 6 knob radios and took many noise things as I tuned around to be either radio artifacts, external noise or something atmospheric.  But now that I can see them it is fascinating.
  • Walt - KZ1FWalt - KZ1F Member
    edited November 2016
    Peter, you deprived yourself of an awesome experience. Back in the mid 80s I drove N1CUZ out to Newington from Scituate RI, where we both lived. That, BTW, is the vintage 1700 white house listed on my qrz page. That was prior to computerized logging so we took turns logging for the other who was OP. Imagine calling cq from Afghanistan, that's what it was like. Stations appeared out of nowhere, in an instant, there where hundreds of them. I can't speak for Bob, who I believe is SK now, but I couldn't write fast enough to stay ahead of him, when I was logging. Do it!

    Panadapter do add a visual component to the process. For chasing dx, consider a simple listbox of calls in descending order by distance from your qth, independent of band. Upon selection, it would lock your rcv on his xmit and position your TX the appropriate offset plus clear freq. I think there are use cases where a pan might be superfluous. My first was an hw-101, I had the pleasure to build myself. Both building and operating where hugely rewarding experiences.
  • KE9NSKE9NS Darrin Kohn Member ✭✭
    edited December 2016

    Are you referring to the "Barber Pole" artifact on the waterfall?


  • KE9NSKE9NS Darrin Kohn Member ✭✭
    edited December 2016

    I recently added a simple low res call sign waterfall ID transmit feature to PowerSDR.

    EasyPal waterfall ID is the best though.

    Darrin Ke9ns.com

  • Walt - KZ1FWalt - KZ1F Member
    edited November 2016
    Or an app that presents contacts greater than some distance away where you either don't have that qth or that qth on the band they are active on.
  • KC8PKC8P Member ✭✭
    edited March 2016
    I agree with you guys! This is what I suspected from the beginning. Thank you for your help!
  • KC8PKC8P Member ✭✭
    edited March 2016
    Thank you Martin! It is helpful!
  • KC8PKC8P Member ✭✭
    edited March 2016
    Danny, What is the signal on the left on 14.222? Do you know? I have these too, on 40m is quite strong, every 60Hz...

    see this https://www.youtube.com/watch?v=u_2jFgUZ4Mk

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