Daniele, the ususal rule of thumb is that you don't need any preamplifier if you get a big increase in the noise level when the antenna is connected. It is best to make the comparison with a dummy lo
V = 2*Pi*f*N*A*u0*H = 2*Pi*f*N*A*B Where f [Hz] N [turns] A [m^2] H [A/m] B [Tesla] u0 = 4*Pi*10^-7 If not properly aligned with the field, multiply by cos(angle). http://vk1od.net/antenna/SmallUntun
Yes, or building a simple "SoftRock style" direct conversion front end and feed the audio to the soundcard for further processing by Winrad or similar software capable of processing I/Q audio. What y
Yes please! If there is interest, I can make the document available for download on a temporary web address. 73 de Johan SM6LKM Chris Trayner wrote 2010-04-26 09:19:
Hi Daniele, yes, absolutely. A simple resistor is very quiet compared to the noise figure of most LF receivers. An ideal resistor has a noise voltage of about 0.128 * R^0.5 [nV/(Hz^0.5)] at room temp
I did. It was my first attempt to write a window$ GUI program from scratch :-) It doesn't have any narrow band analysis functions like waterfall etc. Programs such as Wolf's Spectrum Lab and Alberto'
Pete, my PIC WSPR controller is here: http://web.telia.com/~u33233109/ GPS is not necessary, in addition to the serial input which extracts UTC time from a GPS NMEA data stream, there is also a separ
A copy of the article can be downloaded from here: https://sakerlagring.telia.se/user/Share.aspx?id=bf9b3f03-8865-4b86-83de-2cb9a30a6e70 If the link is broken, please copy & paste it into your browse
Jacek, LF, I have measured SAQ's "backwave" on a few occasions in the past and I think it was about -17dB referred to key-down, about 4kW output. The Alpha signals, when active, are easily copied her
Roger, the programs SOILSKIN and EARTHRES by G4FGQ (SK) will not answer your questions directly but they are related to your questions and they are interesting to play with (many of his programs are)
Hi, just in case someone is interested, my simple panoramic VLF receiver SAQrx has moved to a new home at: https://sites.google.com/site/sm6lkm/saqrx (my ISP went from free webpage hosting to non-fre
Yes, a DC blocking capacitor is a good idea in some cases. For example, between the audio amp's output and the primary of a matching transformer. Otherwise, a large DC current may flow due to a small
