A new Receiver list with sorting and station saving

edited September 2017 in KiwiSDR Discussion
I have been fiddling with my sortable list of current stations.

the data comes from John's page of active receivers - thank you, John.

Check out the features and let me know where to go from here.

Currently there is an azimuthal map that can be dragged around to sort the list of receivers by distance from the center point.

It is also possible to enter the callsign of a station in the database. Currently the list contains 8,000 odd hams who have entered their locations in my hamlocator page and a few new stations such as CHU, WWV, WWVH, etc. Entering a known station finds the closest receivers (not necessarily the ones with the best propagation - but that is on my list for the future) and a frequency, if known. Please feel free to add to the database with your own favorite station.

The list an be sorted by distance, country, gridsquare (longitude) and frequency.

I would like to add propagation prediction and some merit value for each receive station on the desired frequency. Later...



  • This is awesome!
  • edited September 2017
    Hi Peter,

    I really like the website and map :-)

    Some suggestions as requested.

    Can the mode and zoom level be selected from separate drop down lists with suitable default values, so that in most cases only the frequency needs to be entered each time.

    The next suggestion (for further discussion) is based on this premise. 

    I sometimes come across a new signal that is weak and I'd like to try and identify it, to do this I have to go to several SDR's (that I have already noted as being good in each region) and then open up a browser session, enter the frequency and mode and then listen for a period of time to each one in turn, in order to see if I can hear the signal and then determine how strong it is on each SDR.

    By doing this and applying a basic knowledge of propagation at the time of day I'm then more able to estimate which part of the world the signal is emanating from.

    The suggestion is that once the search criteria are entered and the list is formed, could there be an option for the application to scan the list of receivers that have a spare slot available and check the entered frequency to test which receiver returns the best S/N ? 

    It may be that it's not necessary to scan all the receivers, but perhaps just those with the '100' marker indicating that they have good antennas and receive performance. 

    Maybe the search could be tailored to SDR's based on the frequency entered and the likely propagation distance for the time of day ?

    So for example if you wanted to monitor a signal from a specific region, on a particular frequency, at a particular time of day. The application would then choose to scan just those SDR's that were a suitable skip distance away and most likely to be in the coverage area as predicted by VOCAP (or similar).

    Once again Peter (John and others), thanks for your work. It's contributions like this that really push the boundaries of what is possible and which lead to even more innovative ways of utilising this wonderful, worldwide, distributed network of receivers.


    Martin - G8JNJ

  • Thanks Martin.

    It really helps to know what users would like to see as we all have different interests and habits.

    You are thinking exactly on the lines that I am. I haven't quite figured out the best way to get there yet. One possibility is to incorporate the propagation into the map. Here is an example showing the propagation from/to John's receiver on 20 meters the other day. The hot spots are where the SNR should be best (absent solar flares).


    But that is a bit too complicated, maybe.

    The other option is to have a propagation table like this one that is already in DX Monitor, so easy to replicate:


    Both images based on VOACAP path analysis from the transmitter to the receiver.

    So many projects - so little time - which explains why this one has been on my mind for so many years.

  • Very nice....

    As these improved lists etc become available, an accurate frequency coverage listing becomes more relevant. For example, I know my systems works to 10 KHz, with reduced performance below 100 khz but not to 0 khz. K2ZN has a HPF so only goes down to 1700 KHz.  He'll give set his config to reflect that. Others should do the same to reflect what their antenna/filter systems allows reception of.
  • Hi Peter,

    Whilst re-reading the KiWi quick guide, I came across a reference to the priyom 'pavlova' dispatcher.

    "This provides live probing of available receivers and is performed in client-side javascript in your web browser.

    There is a pavlova instance hosted at http://s.printf.cc/. It accepts two parameters: the area code, and the tuning string. The tuning string is optional. For example:

    http://s.printf.cc/#p/6400am will redirect to an available receiver in the Pacific ("p") area, tuned to 6400 kHz AM;

    http://s.printf.cc/#m/9450usb will likewise redirect to a receiver in the Mediterranean ("m") area tuned to 9450 kHz USB;

    http://s.printf.cc/#n/ will find and redirect to an available receiver in North America ("n"), but without tuning it to any specific frequency.

    The URL format is pretty flexible, so http://s.printf.cc/?p/6400am works too or even http://s.printf.cc/p/6400am could be supported, although the preferred way is using a URL fragment (the #-part), because it doesn't need to be sent to the server."

    I tried this out and it seems to work fairly well.


    Martin - G8JNJ
  • edited September 2017
    I have now added a propagation link to each receiver which will open a page with detailed propagation predictions.

    I am not satisfied with the user interface yet, but some feedback will help with that, I'm sure.

    For propagation predictions, first choose the transmitter by entering the callsign (if previously saved), entering the coordinates, or dragging the map to the transmitter location. Press Save to save a new callsign, or Center Map to center the map on the transmitter.
    Drag the map to search for receivers in different locations or just choose your favorite receiver from the list. Click the image propagation icon in the receiver list to open a new page with detailed propagation predictions.


    Let me know what you think.

    I think the next addition might be a star rating beside each receiver. The only problem with any single rating is that the use case differs so much from 10 meters to VLF that one overall rating is not sufficient. Maybe a link to a detailed feedback page. I could become the travelocity of KiwiSDRs.


  • Thanks Peter, you're definitely on the right track. I've taken the liberty of putting your link at the Status field of my Kiwi.

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