Amateur Radio Stack Exchange
Amateur Radio Stack Exchange

Questions tagged [lf]

Low Frequency: frequencies in the range of 30 kHz–300 kHz.

7 questions
4
votes
3 answers

What are the technical reasons that there are no FM transmissions on the long, medium, or shortwave?

Why are there no frequency modulated broadcasts on the long/medium/short wave, but only on VHF? I'm sure there are many historical and political reasons (long/medium/short wave were already in use for AM when FM radio was developed, VHF still had…
JanKanis
  • 405
  • 2
  • 11
4
votes
1 answer

60kHz WWVB receiver help

I have built a large ferrite loopstick antenna based off this video. I live in Washington state and am trying to receive and decode WWVB. I can get my antenna to resonate at 60kHz with ~700 pF of capacitance. I am lost on the receiver/preamp…
Max686
  • 41
  • 2
3
votes
1 answer

Can one send data over Short-wave frequencies?

I have an inkling of an idea- a modem system communicating over Short-wave. I know that WiMAX already exists, but the difference is that, while WiMAX works on the Gigahertz frequencies, and most concepts for Ham Radio ones think Megahertz…
Rory Yammomoto
  • 31
  • 1
  • 3
3
votes
2 answers

How to make ELF-ULF antenna myself?

I want to check the EM pulse between 3HZ-3kHZ with N9041B UXA Signal Analyzer,it seemed the only antenna I can use is Aaronia MagnoTRACKER,but the price is not affordable. Then I plan to make ELF-ULF antenna myself,could you pls give me some…
kittygirl
  • 600
  • 2
  • 10
2
votes
3 answers

Ferrite unun transformer to match antenna resistance loads of <50Ω?

For LF/MF (2200m/630m), I am interested in the situation of a vertical antenna with capacitance hat top-loading, where the vertical antenna is VERY short compared to wavelength, and the antenna is brought to resonance across operational frequencies…
photosynthesis
  • 75
  • 4
1
vote
1 answer

Receiving medium - low frequency CPU signal

I'm trying to listen to the CPU freq's my PC produces (kinda similar to what was done here: https://github.com/fulldecent/system-bus-radio) I do see a clear signal that comes from the CPU (I know that because I can control it by reading memory…
George Lashenko
  • 11
  • 1
1
vote
1 answer

Utility pit MW/LW omnidirectional antenna

I am looking at antennas for a rather unusual application: mounted under a utility pit lid (manhole cover). The goal is to receive commercial MW/LW stations. The antenna has to be attached to the underside of the lid with a magnet. To make it easy…
user1211
  • 129
  • 4