LF,
I've been on a tour in Freiburg over the weekend and just back home. It
was possible to check my modified GSM external car antenna (with a
magnet foot), modified as an active antenna for 137 kHz. The RX is my
homemade receiver (12V/50mA, SBL-3, 125 kHz downconverting). Between RX
and antenna is about 4m RG174. Signals were monitored on my netbook
using SpecLab. The soundcard drift is compensated by locking on DLF (153
kHz) which worked very well. I've used no external GPS module so the
etal wasn't in a PLL, never mind.
I've been watching the QRSS-3 and QRSS-60 active region while beeing on
the highway A5, see:
http://maps.google.de/maps?f=d&source=s_d&saddr=heidelberg&daddr=freiburg&hl=de&geocode=FSzQ8QIdXXOEACnN3MwOBcGXRzHXOiREAOrm7w%3BFQJh3AIdx9Z3ACll1gtWJhuRRzGwV9-lt2sfBA&mra=ls&sll=47.997186,7.853767&sspn=0.145654,0.438766&g=freiburg&ie=UTF8&ll=48.821333,7.910156&spn=4.585752,14.040527&z=6
This was the first test with the /m LF antenna and there seems to be a
lack of sensitivity of about 20 dB. The LF noise is just a few dB above
the soundcards noise, DCF39 appeared at 45 dB on 2.8 Hz. There was
almost no local noise from the car, just some 420 kV lines near the
highway caused QRM when driving under or near them.
Although there is a lack of sensitivity, it was anyway possible to copy
DF6NM in QRSS-60 and in HELL (480 mHz FFT, traces visible) during
driving. See the attached pictures. Copy of "NM" was near Karlsruhe,
about 200 km distance.
I hope to improve the SNR / sensitivity now and will be able to copy him
and others in CW to try a /m xband QSO...
73, Stefan/DK7FC
DF6NM from the A5.jpg
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DF6NM in HELL.jpg
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