Sunday, July 24, 2016

WSPR screens 24hrs 70 50 MHz . SolarEdge PV converter 24*7 QRM!



                                        50MHz RFI  picture of SolarEdge SE8K PVC at 50m distance
Finally  i found the noise source that was frustrating weak signal reception here at the high frequencies. I took again my IC706 with a small motor bike battery to investigate better this time.
I had to improvise with the rig I have the old but fb IC706 a bit heavy but good.
I really need a  selective broad spectrum receiver  that covers the whole HAM radio spectrum.
The SDR RTL USB 40-1800MHz receiver is a thing that could do that job.
But this RTL stick is only working stable / reliable with W10  I could not use it with W7 
and it is  missing the short wave bands below 40MHz
The red Pitaya SDR could be the best device a reason more the purchase this miracle  device..

 The above 50MHz spectral QRM source is my neighbors  SOLAREDGE  SE8K at 50 distance.
My normal noise floor is below -60dB but since about a year my low noise environment is disturbed.
I did suspect the PV- converter at my ( only) neighbor but when it  was switched off once the QRM did not disappear. Now i know it was switched off too short. The QRM is caused by its CPU unit internal and this CPU power needs at least 10 seconds to drop to zero.
 Even in nighttime stand-by the CPU generates a wide noise spectrum around 50MHz picture but also at 28MHz i find the birdies. The picture spectrum did pass a 50MHz selective preamp
 What is keeping the PV-converter busy at night?   The noise level increase in the direction of the SE8K at 50m is about 20dB The birdies are very accurate and stable 200kHz  separated  peaking another 10dB over it's noise band.  This spectrum is the fingerprint of the Solaredge SE8K .
After power off in 10 seconds  the noise disappears  then CPU power is dropped.

 My own PV converter SolarFrontier 3600 does not show QRM  I could not detect extra noise close to this PV-Converter. The birdies I found are radiated from the shd-TP network cable's.

So SolarFrontier SFW-3600 is ham grade
The Solaredge SE8K is a  radio disaster.

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