RSGB react to ofcoms lies about VDSL qrm

Noise and interference issues?
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Tim Bucknall
Posts: 3296
Joined: 01 Oct 2014 14:55
Location: Now stranded in Congleton

RSGB react to ofcoms lies about VDSL qrm

Post by Tim Bucknall » ... 1-2017.pdf

it seems like everyone at ofcom is an incompetent as the guy who came out to me the repeating theme is of not being able to recognise abnormal noise

this is my favourite line in RSGB's response "you were measuring the instrument noise not the environment" :lol:

i have to laugh or i'd explode with rage at the incompetence of ofcock
Rx: Burkhardt Reuter RDR54D1, Elad FDM-S2, Airspy HF+ w/ HS Publications 6 Element R3 -R5 Yagi on rooftop rotator V/H polarization options. Pira P275 RDS analyser

Nick Gilly
Posts: 1650
Joined: 18 Sep 2014 14:17
Location: Whitchurch, Hampshire, UK

Re: RSGB react to ofcoms lies about VDSL qrm

Post by Nick Gilly »

Tim it's not lies that Ofcom told but 'alternative facts' ;)

Seriously though, it mirrors my experience with Ofcom a few years ago.
Good DX.

Nick, Whitchurch, Hampshire.

BW Broadcast RBRX Encore, Kenwood L-1000T, Yamaha T-2, Denon TU-800L, Kenwood KT-1100SD (modified), Yamaha T-85, Sony XDR-F1HD tuners, horizontal Körner 9.2 beam (Antennenland version), Yaesu G-450C rotator

Posts: 1606
Joined: 07 Oct 2014 16:49

Re: RSGB react to ofcoms lies about VDSL qrm

Post by daveB »

Aarrgghh! Good thing I hardly touch HF - and definitely no incentive to invest any time/money. I don't know if the interference spreads all the way into MW - but this is what I get on HF.
Broadband interference.jpg

[I was only checking this out in the previous week as part of chasing down the other interference and was beginning to think "I might as well give up"].

Now (forgive any digression) my brother recently told me he had a friend/acquaintance who is a radio amateur - and he took me round today to visit. To cut a long story short he operates on HF with a Kenwood TS590 and uses an SDRPlay RSP2 to feed it's IF output to HDSDR and controls the rig via the SDR program. So we played about - I helped him install SDR Sharp build 1361 and got that running and then out of interest we switched his long wire aerial (with 9:1 unun) directly to the SDR, opened up the bandwidth to 8 MHz centred around 8.6 MHz- and there was exactly the same picture as above. This matches the screenshot in the December RadCom article about VDSL interference.

The noise is around 25 dB above noise floor. Looking at the higher frequencies - using the dipole with 1 m half-ele size there is no interference above 12 MHz. The bump around 7 MHz seems to be due to many strong signals overlapping at this resolution.

Low cost wide band SDRs are certainly show up wideband interference nicely!
Location: Sittingbourne, Kent JO01ji
SDRPlay, AirSpyMini, RTL dongles, ST311, Yamaha TX930. 5 ele yagi 20ft agl - 70 deg. FM5 - 80 deg, 5.1 Yagi 16ft agl - 120 degFM5 -180 deg. Vert 3-ele Moxon - 80 deg. Shielded magnetic loop 0.1-200 MHz - 10 ft agl

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