KiwiSDR Direction Finding (TDoA) Extension

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I maintain that the KiwiSDR has been one of most value for money and interesting pieces of amateur radio equipment I have purchased.

One of the main reasons for that view is the continual updating of the software and the addition of new features.  The latest is Direction Finding (DF) using Time Difference of Arrival (TDoA).

A review which provides the detail is here:



KiwiSDR TDoA Direction Finding Now Freely Available for Public Use

A test was performed against DDK, a RTTY weather service originating from near Hamburg in Northern Germany. Frequency 10100.8 KHz.

Three KiwiSDR were chosen, based on good geometry to the known location of the target – G0LUJ, F1JEK and UR5VIB. The test was successful.











Categories: KiwiSDR, TDoA

Reverse Beacon Network (RBN) Real-Time Azimuthmal Map

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A new release of RBN Aggregator now supports FT8 in addition to the traditional modes. It was installed at this location as seen below:

G0LUJ RBN Aggregator 5.1, monitoring 8 bands

Given the large volumes of textual data, interpretation of the monitoring results was difficult – what was needed was a real-time graphical solution that could easily provide a general overview of propagation conditions based on the data.

HA8TKS, with credit to an idea by CT1BOH, has implemented such a solution which I have found to be very useful. It defaults to the last 15 minutes of RBN data from the spotter that is selected and auto-updates. Observing the path lines on the globe over a few minutes gives one a very quick indication of conditions at that spotter’s location. I have added a link to the website top menu.

Map of RBN Spotter G0LUJ

Categories: CW, FT8, RBN, Uncategorized

HF Noise Reduction, VHF Sporadic-E

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The reactivation of the KiwiSDRs from the home location revealed a noisy spectrum with weak signals, and pronounced vDSL interference.

vDSL Interference 8.5-12 MHz

The spectrum was not a surprise, and was the reason why I initiated a remote antenna project last year. Now that the remote location is no longer available, it was evident that I would have to make the best of it from the home location.

Using lessons learned from remote antenna project, the following actions were performed:

1) The 8 port Ethernet switch, which was plastic, was replaced for one with a metal case. The switch was then moved 20m away from the receivers (and antenna) and the receivers were connected to the switch with CAT6 shielded Ethernet cable.

2) All power supplies were assessed. It was found that the non-switch mode supply powering the Wellbrook antenna had gone faulty and was producing birdies across HF. It was replaced.

3) After reading about how domestic telephone extension cables can re-radiate vDSL signals, the telephone extensions (which are unused) were disconnected at the master socket.

4) The Wellbrook ALA100LN antenna was moved further away from the property, with the head unit raised to a level of 2m above the ground.

5) The Medium Wave (MW) bandstop was re-inserted into the system to improve non-MW weak signal reception by reducing overload.

The overall result was an improvement and tests against known signals, such as RAF Volmet, demonstrate that it is now adequate for general reception, and probably as good as could reasonably be expected from a suburban location.

The recent Sporadic-E openings provided an opportunity to assess the KiwiSDR noise floor and reception by examining the 10m CW beacon band. The frequency labeling of the beacons took about 2 hours, spread over a couple of days:


10m CW Beacons


I will add the 10m CW beacon monitor to the website when I have configured it.

6m FT8 has been very busy. I have concentrated on the receive setup for optimisation. Highlights below:


Ukraine on 6m CW


PZ5RA on 6m FT8


XE2JS received on 6m FT8

Monitoring of 4m has resumed.


Categories: 10m, 4m, 6m, CW, FT8, HF, KiwiSDR, LF, VHF, WSPR

KiwiSDRs reactivated

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After a holiday, and little amateur radio activity, I have reactivated the 2 KiwiSDRs from the home location.

The performance is not as good as at the previous remote and RF quiet location, but is adequate enough for general listening and will provide further opportunities to pursue noise reduction strategies.

KiwiSDR1 is currently devoted to WSPR, KiwiSDR2 is available for public access from the top menu.

I have suspended 70 MHz reception for the moment to free up an antenna port for a KiwiSDR – activity levels have been very low on this band so far this season.

Categories: Uncategorized

9K2GS received on 50 MHz FT8

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The consensus among the VHF community that this week would see the real start of elevated conditions (particularly for those of thus in more northerly latitudes) has been confirmed by regular openings to the Mediterranean countries. This morning, Friday 4th May 2018, the first medium distance DX, 9K2GS, was received on FT8 mode.

Categories: Uncategorized

Amateurs in Ireland receive new spectrum allocation between 30-49 MHz

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Dermot, EI7IX, noted on the ON4KST chat room that the Irish regulator, COMREG, has released new licence guidelines – the highlight of which is a new secondary allocation between 30-49 MHz.

COMREG document

Slovenia and South Africa already have small allocations around 40 MHz.

The multi-frequency beacon, GB3RAL, is active on 40.0050 MHz. This raises the question of some kind of allocation (probably secondary) in the UK.

One can examine the Ofcom Frequency Allocation Table (2017) to see who the existing users of this spectrum are in the UK to determine the possibilities.

Categories: 30-49 MHz, VHF