ARLA/CLUSTER: Experiencias em VLF ( 9kHz) com Microwatt ERP

[João Gonçalves Costa]

Microwatt ERP 9 kHz signal copied at 45km

In the early hours of Thursday morning, Mar. 3, Chris G3XIZ transmitted a few microwatts ERP of VLF at 9.0909kHz, his signal was heard 45km away by Roger G3XBM.

This is possibly the furthest distance yet acheived by a UK Amateur station on 9kHz.

Roger G3XBM writes:
Chris G3XIZ was transmitting a test carrier on 9.0909kHz using, I think, 150W into his normal inverted-L antenna that he uses on 136 and 500kHz matched with a large VLF loading coil. ERP would have been just a few uW.

Using Spectrum Lab software with 423uHz bandwidth FFT settings I managed, for the first time, to get quite good copy of his signal using my 80 sq metre loop and the small FET preamp shown on my website. Between 0300-0600 his signal was around 10dB S/N in this narrow bandwidth. There are screen shots on my blog and website. Distance between us is around 45km.

I think this is a new record for a VLF transmission by a UK amateur although if Paul Nicholson in Yorkshire copied Chris (he should do as he has a terrific VLF receiving system) then this DX record will have already been broken.

Well done Chris.

73
Roger G3XBM

  

On his Blog Roger reports receiving a new German station on 8.970022kHz, Uwe DJ8WX, at a distance of 645km, see
http://g3xbm-qrp.blogspot.com/

Amateur Radio Communications Below 9kHz
http://sites.google.com/site/g3xbmqrp/Home/10khz

G3XBM gets 8.97 kHz transmitter permit
http://www.southgatearc.org/news/october2010/g3xbm_transmitter_permit.htm