HF Noise Reduction, VHF Sporadic-E

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.


4 Replies to “HF Noise Reduction, VHF Sporadic-E”

    1. Hello,

      Unfortunately it is not possible for users to add their own call-sign labels – only the KiwiSDR administrator has that capability.

      Allowing KiwiSDR users to have this capability is on the ‘wish list’ for the KiwiSDR developer, as others have already requested it.

      You can follow developments – or ask questions – on the official forum, kiwisdr.com, where you may find more detail.

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