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using_sdr

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using_sdr [2025/03/17 02:04] – added an example of the bandpass in lsb m7toxusing_sdr [2025/03/17 22:13] (current) – explained am and fm m7tox
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 The Hack Green website, in all its web 1.0 glory. (Note: this is the HF site, there is a link at the top to switch to the VHF one instead.)  The Hack Green website, in all its web 1.0 glory. (Note: this is the HF site, there is a link at the top to switch to the VHF one instead.) 
 </WRAP> </WRAP>
-Getting started is as easy as selecting an SDR from the list, though for this guide we will be using the [[http://hackgreensdr.org:8902/|Hack Green]] SDR, which is based in the //sunny// county of Cheshire, England. It may be easier to follow along using this, as there are some visual differences between the different sites. Hopefully, once you are comfortable with using this one, you can experiment with the others and find your own way. +Getting started is as easy as selecting an SDR from the list, though for this guide we will be using the [[http://hackgreensdr.org:8901/|Hack Green]] SDR, which is based in the //sunny// county of Cheshire, England. It may be easier to follow along using this, as there are some visual differences between the different sites. Hopefully, once you are comfortable with using this one, you can experiment with the others and find your own way. 
  
 You //should// hear the SDR audio as soon as you open the page, likely just static. A note at the top of the page states that Firefox users might have to change permissions to allow websites to auto-play audio but I've never had an issue with this. There are some [[https://en.wikipedia.org/wiki/Radio_button|radio buttons]]((I was interested to find that the name 'radio buttons' did in fact come from actual radios. Maybe you will find it interesting, too.)) to change if the waterfall and/or audio use Java or HTML5. It defaults to HTML5 and the vast majority of users likely want to keep it that way, as Java isn't natively supported in many browsers anymore.  You //should// hear the SDR audio as soon as you open the page, likely just static. A note at the top of the page states that Firefox users might have to change permissions to allow websites to auto-play audio but I've never had an issue with this. There are some [[https://en.wikipedia.org/wiki/Radio_button|radio buttons]]((I was interested to find that the name 'radio buttons' did in fact come from actual radios. Maybe you will find it interesting, too.)) to change if the waterfall and/or audio use Java or HTML5. It defaults to HTML5 and the vast majority of users likely want to keep it that way, as Java isn't natively supported in many browsers anymore. 
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 \\ \\
 \\ \\
-===== Interface: =====+===== Interface =====
  {{ hack_green_sdr_interface.png |}}  {{ hack_green_sdr_interface.png |}}
 == Name == == Name ==
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 == Frequency == == Frequency ==
 You can manually enter a frequency here, which may be easier if you want to be exact. The input is limited by the band you are on, so if you try and enter 6000 on the 40m band, it won't tune because that's outside the limit (there is a little leeway either side though). The buttons below the input box are useful for nudging the frequency up or down by a little '+', a bit more '++', or quite a lot '+++'. I recommend using these little buttons for fine tuning as it's a bit easier than dragging with the mouse. You can manually enter a frequency here, which may be easier if you want to be exact. The input is limited by the band you are on, so if you try and enter 6000 on the 40m band, it won't tune because that's outside the limit (there is a little leeway either side though). The buttons below the input box are useful for nudging the frequency up or down by a little '+', a bit more '++', or quite a lot '+++'. I recommend using these little buttons for fine tuning as it's a bit easier than dragging with the mouse.
 +
 +The memory bit here lets you store the current frequency and bandwidth mode, which you can use 'recall' to return to. This might be useful if there's always something going on around a certain frequency like a repeater. 
  
 == Band == == Band ==
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 == Bandwidth == == Bandwidth ==
-<WRAP round box 500px right> +This bit is potentially the easiest bit to get wrong as a beginner. They are arranged in columns, if that wasn't evident. The left 'wider' and 'narrower' change the width of the yellow bandpass selector, although generally you won't need to very often. 'CW'((Continuous Wave)) is for morse, 'LSB'((Lower Side Band)) is used for frequencies below 10MHz, 'USB'((Upper Side Band)) is for frequencies above 10MHz. AM is twice as wide as SSB, for reasons that you can discover yourself by researching what SSB is (I recommend you do so, you'll need to for getting your license), so if you see something that looks twice as wide as the SSB signals, it might be regular AM. Some bands use FM more readily than AM modes, especially VHF. You can tell if something is FM because it will be symmetrical and looks like how a voice audio waveform looks on programs that show you the audio visually. Some of these have wide/narrow options, which may improve how well you can hear the signal, though generally it's fine on the 'standard' setting rather than the 'narrow' one. 
-{{ :lsb.png |}} +
-The yellow bandpass set to Lower side band mode and placed over the signal in a way that the audio is readable. Note the vertical bar on the right is placed just on the side of the signal, whilst the horizontal line is approximately the width of the signal. +
-</WRAP> +
-This bit is potentially the easiest bit to get wrong as a beginner. They are arranged in columns, if that wasn't evident, and you probably want to avoid the wider/narrower ones on the left in most instances. 'CW'((Continuous Wave)) is for morse, 'LSB'((Lower Side Band)) is used for frequencies below 10MHz, 'USB'((Upper Side Band)) is for frequencies above 10MHz, AM and FM are probably self explanatory. You may find that for these various options, the wide/narrow options improve how well you can hear the signal, though generally it's fine on the 'standard' setting rather than the 'narrow' one. +
  
 == Waterfall view == == Waterfall view ==
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 The panel next to the 'waterfall view' has a few different options.  The panel next to the 'waterfall view' has a few different options. 
   * The green bar shows the signal strength, which is what people use to give readability/signal reports. When you hear someone say '5/9', the '9' bit is because the green bar here reads 9, and is a feature on lots of radios, analogue or SDR.   * The green bar shows the signal strength, which is what people use to give readability/signal reports. When you hear someone say '5/9', the '9' bit is because the green bar here reads 9, and is a feature on lots of radios, analogue or SDR.
-  * Mute: I'm sure you can work this one out on your own :)+  * Mute: I'm sure you can work this one out on your own
   * squelch: This turns a squelch function on, filtering out the static in the background and only playing audio when the signal strength is high enough the software feels there is a transmission. If squelch is ticked //on//, but you can't hear anything when the waterfall looks as though there is something there, try turning it off. There may be a faint signal that the squelch is blocking.    * squelch: This turns a squelch function on, filtering out the static in the background and only playing audio when the signal strength is high enough the software feels there is a transmission. If squelch is ticked //on//, but you can't hear anything when the waterfall looks as though there is something there, try turning it off. There may be a faint signal that the squelch is blocking. 
   * Notch1/Notch2: two options for trying to filter out unwanted beeps and noises, you can use one, both, or none. I don't find it particularly useful.    * Notch1/Notch2: two options for trying to filter out unwanted beeps and noises, you can use one, both, or none. I don't find it particularly useful. 
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 == Logbook ==  == Logbook == 
 You can log callsigns of heard stations and a comment here if you like. The buttons here also let you see the logbook itself. Interesting to have a read through to notice patterns or clusters of transmissions, or if you're wondering if anyone heard your own transmissions.  You can log callsigns of heard stations and a comment here if you like. The buttons here also let you see the logbook itself. Interesting to have a read through to notice patterns or clusters of transmissions, or if you're wondering if anyone heard your own transmissions. 
 +
 +
 +====== Step by Step ======
 +Follow these steps for a short adventure across the 40m band. It's a reasonably active band and is a good place to start (In the author's opinion).
 +
 +  * Open the Hack Green SDR (Make sure you're on the HF one, not the VHF one. If you click [[http://hackgreensdr.org:8901/|>this link<]], you'll be in the right place.)
 +  * Enter your name or callsign, if you like.
 +  * Select the 40m band. 
 +  {{40m_band.png}}
 +  * Type in '7000' into the Frequency box, or drag the bandpass slider across to somewhere near. This is the bottom of the 40m band, which has different sections of it for different things. Have a look on the [[https://rsgb.org/main/operating/band-plans/hf/7mhz/|RSGB page on 40m]] for info on what is where. Note that '7MHz' is the same as '40m' and are used more or less interchangeably. 
 +  * Have a look around the lower end of the band, between 7000 and 7040 kHz. You may see some thin, broken lines. These are CW, or morse code.((I could point out that it's not actually a code, it's a cypher, but that would be incredibly pedantic.)) Make sure you have changed your bandwidth to 'CW-wide' or 'CW-narrow', probably just go for wide, and click underneath the signal on the waterfall to move the bandpass to that area.  
 +  {{cw_example.png}}
 +  * Adjust your frequency tuning either by dragging the yellow bit gently (finding out where to click to move it and not adjust the width takes a bit of practice), or by using the buttons underneath the frequency input box. 
 +  * You should be able to hear the CW now. 
 +  * Move up the band a little to between 7030 and 7060. You will probably see some signals here, they might be quite wide, or they might be thin. Switch to LSB and tune to it. The LSB bit doesn't really matter because this area of the band is for data and so it will sound robotic and strange, but having it on LSB will let you hear what that sounds like. 
 +  {{data.png}}
 +  * The rest of the band from 7060-7200 kHz is for SSB((Single Side Band, (LSB/USB) )) and is where you'll hear people talking. Have a scan around and look for vaguely rectangular columns. Use LSB because the frequency is below 10MHz and that's the accepted convention. You'll notice the signals are about the same width as the yellow bandpass bit. Try and tune to them, and adjust with the buttons rather than dragging for best results. You will find that using SSB modes you have to be a little more precise to stop the voices sounding distorted. 
 +  * Here is a signal I found, The horizontal lines are interferance and aren't significant for what we're doing. The yellow bandpass set to Lower side band mode and placed over the signal in a way that the audio is readable. Note the vertical bar on the right is placed just on the side of the signal, whilst the horizontal line is approximately the width of the signal.
 +  {{lsb.png}}
 +  * Here is a weaker signal, it's harder to see but it's still understandable. You will have to adjust the frequency and the various settings to get a good sound out of signals like this. 
 +  {{weak_lsb_signal.png}}
 +  * Here is a stronger signal beside another signal that is very close to it on the left, making it look a bit like one signal that's thicker than the others. You may have to adjust the left side of the bandpass to stop picking up the one to the left. 
 +  {{stronger_lsb_signal.png}}
 +  
 +  
 +===== In closing ===== 
 +That's all there is to it! Most WebSDR sites are similar but may have slightly different interfaces and options, so have a play and see what happens. You can't break anything so you might as well try out all the buttons. 
 +
 +Next, maybe try out the Hack green VHF site, particularly the 2m band as this often has some chatter during UK daytime. Then have a look around some other sites, maybe in a different country to you, or on different bands. If you are using a WebSDR in ITU region 2, the 40m amateur band can be wider up to 7300MHz so there may be more space to look around. Also, 7200MHz is somewhat infamous in the US for being the target of disruptive behaviour, so if you hear weird goings on around that frequency, that's why.
 +
 +Remember to have a look at the bandplans to see which frequencies to look at, and remember <10MHz = LSB, >10MHz = USB.  
 +
 +If you haven't already, consider joining the OARC discord server, which is incredibly active and full of helpful and knowledgeable people who can answer any questions you have. 
 +
 +I hope you enjoyed this guide and found it useful, I made it because I couldn't find a similar guide aimed at beginners when I was starting out. If you enjoyed it, please let me know in the OARC discord. Also, it probably goes without saying, but feel free to add to this guide if you see fit. :)
 +\\
 +73's - M7TOX (Connor)
 +
 +
 +
  
using_sdr.1742177098.txt.gz · Last modified: 2025/03/17 02:04 by m7tox