G8JNJ
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Persistent suspicious connection
I have noticed a problem, where folks stay connected or a long period, but they are only viewing the waterfall or spectrum display, and maybe doing something else.
So the frequency and mode they have selected, are sometimes misleading with regard to the purpose the KiWi is being used for.
This is usually indicated by being fully zoomed out e.g. z0
Regards,
Martin
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Wonder what this is at 5300Khz? - its always there.
Before swapping supplies, make sure that it is the Apple power brick that is causing the problem. It may well be something else.
The signal will most likely change its characteristics if the power supply load is altered in some way.
Try a different make of supply and see if the interference on that frequency changes or goes away completely.
Regards,
Martin
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Another mystery signal :-)
There are so many amateur digital modes these days, it is often very difficult to say what is being used.
It is around the frequencies typically being used for SSTV, and it could be Digital SSTV, but that is just a guess on my part.
The Signal ID Wiki is a good place to start when trying to ID unknown signals.
https://www.sigidwiki.com/wiki/Signal_Identification_Guide
Regards,
Martin
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Private use of a KiwiSDR receiver in France
Hi Andy,
I understand the points you are making, but having previously discussed this with Philippe, I think there are some valid concerns, that may discourage other people, in other countries, from operating a KiWi.
If a simple fix, which John has already implemented, can help remove some of these barriers, then surely it is a good thing ?
Some countries are extremely sensitive about some aspects of the radio hobby, and to be honest, if I was living in one, I wouldn't be running a KiWi. It's easy to forget this when living somewhere that is more "relaxed" about such things.
Callsign piracy has always been an issue, and using an alpha-numeric string (or emojis) to identify an individual doesn't mean that they are who they say they are. However, I can understand the problem for the KiWi admin, if someone else decides to use your callsign, and you, the legitimate owner, find out, and then blame the admin for something that he has no control over. This may sound unlikely, but I have experienced similar problems when we had the "Chat" facility enabled on one of our websdr's, which caused so many issues we, (like most other websdr admins) removed it. Any public site, that has the ability for folks to anonymously post comments, no matter how brief in content, will unfortunately be abused.
Andy - "they" already know, who you are and where you are :-)
Regards,
Martin - G8JNJ ( or am I )
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Map pins meaning
Hi Glenn,
I have used WSPR Daemon with good results, but unless you have set aside some KiWi channels to allow it to run, it's not really applicable to the average KiWi installation.
Although not calibrated against a known noise reference, the graphs I have obtained using the standard KiWi SNR stats are almost as detailed as the ones I obtained using KiWi Daemon, in therms of indicating propagation changes. But unlike WSPR Daemon, it's a background process and doesn't require additional resources such as a RasPi (scarce at the moment), or consume precicous receive channels in order to work.
In addition I feel that the use of WSPR is beginning to wane somewhat, and FT8 is now taking over the world of Amateur radio. In fact if FT8 had a mechanism for reporting transmitted power and a full 6 digit locator, as does WSPR, I think WSPR would be in further decline for use as a propagation indicator.
With this in mind, it would be nice if the KiWi could support more of the JT/FT modes as an extension, in addition to WSPR, as I believe the libraries are available, but I guess it's not particularly high on the adgenda for John these days.
Regards,
Martin
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Quiet switch mode power supply (SMPS) for KiwiSDR
Sometimes, when used inside a Switched Mode Power supply, the additional choke inductor in the ground (L3 in the circuit) can sometimes be more problematic than useful.
I tend to wire the DC 0v / -ve directly to the mains earth, but depending upon the local configuration, this can also make things worse.
Unfortunately, it's one of those cases where, although it may be good practice to do certain things, you generally have to experiment, in order to find the best solution for your own setup.
Regards,
Martin
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Please protect your KiwiSDR 2 from the high-level RF fields of nearby transmitters
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Enhancement: Add SYNOP-Decoder
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Private use of a KiwiSDR receiver in France
Hi Philippe,
I'd agree with John that it doesn't make sense to list KiWi's that folks can't openly use.
But I do understand your reservations, and some countries are definitely more restrictive than others.
Short range local VHF / UHF communications are certainly more problematic from a legal perspective than HF communications, which generally tend to completely ignore geopolitical boundaries
Maybe it would be worthwhile emailing some of the other KiWi admin / operators in France, to see if they have the same concerns as yourself ?
Regards,
Martin
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600 kHz wide mode
A bit more information for those interested in Wave Radars, cut an pasted links from discussions on other sites.
CODAR and WERA (now Helzel) are very similar systems, and I think that folks tend to call all of them CODAR, a bit like some brand names becoming used for all products of a certain type regardless of the actual manufacturer.
There are plenty of WERA systems operating, but maybe not in the USA, even so the chances are you will have heard one, but thought it was CODAR.
List of USA radars including manufacturer.
https://hfrnet.ucsd.edu/sitediag/stationList.php
You can also use this map.
https://cordc.ucsd.edu/projects/hfrnet/
Select station placemarks in the overlay menu to show them on the map.
If you click on each map pin it will give you more data, including the operating frequency.
Alternatively, there is this list, but it takes a very long time to load.
https://hfrnet.ucsd.edu/sitediag/stationList.php
WERA have a range of products, some of which have slightly different characteristics.
The European ones are listed in a table at the end of this document
https://eurogoos.eu/download/eu-hfradar-inventory-2016/?wpdmdl=9972&refresh=63f157c239dcf1676761026
An interactive on-line map of the current European sites can be found here.
https://eurogoos.eu/high-frequency-radar-task-team/
Regards,
Martin