We seek to understand and document all radio transmissions, legal and otherwise, as part of the radio listening hobby. We do not encourage any radio operations contrary to regulations. Always consult with the appropriate authorities if you have questions concerning what is permissible in your locale.

Author Topic: Software Phasing with your SDR  (Read 16173 times)

Offline skeezix

  • Global Moderator
  • Marconi Class DXer
  • *****
  • Posts: 5559
  • Minneapolis, MN
  • What does 'RNO stand for?
    • View Profile
Re: Software Phasing with your SDR
« Reply #15 on: December 02, 2016, 0454 UTC »
That is a great idea.

I might be able to something along those same lines with my ALA1530S+ and the ALA100LN. But since the 43' wire on the ALA100LN is stapled to the house, the ALA1530S+ will have to be rotated to N-S and that' the only position that the ALA100LN can go, unless I restaple it to the E-W part of the house, but then closer to the underground power & mostly pointing right at it. Or... move the thing on the other side of the house and staple it to the garage, then the underground power won't be an issue (in theory). And there is already an old coax running out there (just need to find where the inside end goes).
Minneapolis, MN

Offline Josh

  • DXing Phenomena
  • *******
  • Posts: 4322
    • View Profile
Re: Software Phasing with your SDR
« Reply #16 on: December 02, 2016, 1807 UTC »
I'm thinking more along the lines of some matched active antennas aligned north and south at the end of matched coax lengths, but apparently matched coax isn't that crucial when considering the power of the pc/app to account for mismatches. The active antennas would need to respond best to the vertical component of a signal so I imagine a monopole or dipole antennae in the vertical orientation, well decoupled from surrounding conductors such as mounting poles and etc would take care of that. Sorry to hijack your nice thread Chris but I've lusted for the ability to df hf sigs a long time.
We do not encourage any radio operations contrary to regulations.

Offline Billy the Mountain

  • Jr. Member
  • **
  • Posts: 46
  • MO
    • View Profile
    • Email
Re: Software Phasing with your SDR
« Reply #17 on: December 04, 2016, 0123 UTC »
Isn't this exactly what the FCC does?  Active short verticals arranged in a circle they can electronically steer to DF?
--
Somewhere in MO.
TR7/Sony 2010/SDRPlay/40m dipole/Various other aerials.
Ubuntu 14.04, FreeBSD 10.2, why am I putting OSs in my sig?

Offline Token

  • Global Moderator
  • DX Legend
  • *****
  • Posts: 2122
    • View Profile
Re: Software Phasing with your SDR
« Reply #18 on: December 04, 2016, 0141 UTC »
Isn't this exactly what the FCC does?  Active short verticals arranged in a circle they can electronically steer to DF?

I have never seen their equipment, and I suppose it is possible they do steer using phase, but I think it more likely they use a Doppler based RDF.  The base leg on a vehicle is probably too short for much use in phase based DF.

Interestingly, from this video ( https://www.youtube.com/watch?v=QIGAOLJh-XE&t=16s ) it appears that in their mobile units when they tune to a signal they get automatic direction, not surprising, but also a database comes up and tells them every thing licensed on that bearing.

T!
T!
Mojave Desert, California USA

Offline Josh

  • DXing Phenomena
  • *******
  • Posts: 4322
    • View Profile
Re: Software Phasing with your SDR
« Reply #19 on: December 04, 2016, 1549 UTC »
I saw an article in some mag about fcc df and the pics had one of a line of fairly short monopoles mounted in the ground. Anyway, here's an interesting piece on hfdf with an equally interesting antenna;
http://www.dtic.mil/dtic/tr/fulltext/u2/a577289.pdf
http://ppmtest.com/products/prodyn-products/ground-plane-surface-current-magnetic-field-sensors/
We do not encourage any radio operations contrary to regulations.

Offline Josh

  • DXing Phenomena
  • *******
  • Posts: 4322
    • View Profile
Re: Software Phasing with your SDR
« Reply #20 on: December 06, 2016, 0400 UTC »
We do not encourage any radio operations contrary to regulations.

Offline skeezix

  • Global Moderator
  • Marconi Class DXer
  • *****
  • Posts: 5559
  • Minneapolis, MN
  • What does 'RNO stand for?
    • View Profile
Re: Software Phasing with your SDR
« Reply #21 on: December 07, 2016, 0241 UTC »
While that TCI Blackbird looks cool, the datasheet tells the story:

Quote
ModulationType:AnalogFM,AM,AM-DSBSC, LSB, USB, CW / pure carrier, BPSK, QPSK, pi/4- DQPSK, 8PSK, 16PSK, binary FSK, MSK, 3FSK, 4FSK, 8FSK, 16QAM, 32QAM, v.29, OOK, 4PAM, Manual Morse, Machine Morse, and Noise (contact factory for additional modulation types.)

Where is the C-QUAM? WHERE is it? Sure, HFDF is nice, well, its really, really nice, but unless you're DF'ing in glorious AM stereo, what's the point? 
Minneapolis, MN

Offline Josh

  • DXing Phenomena
  • *******
  • Posts: 4322
    • View Profile
Re: Software Phasing with your SDR
« Reply #22 on: December 07, 2016, 2334 UTC »
While that TCI Blackbird looks cool, the datasheet tells the story:

Quote
ModulationType:AnalogFM,AM,AM-DSBSC, LSB, USB, CW / pure carrier, BPSK, QPSK, pi/4- DQPSK, 8PSK, 16PSK, binary FSK, MSK, 3FSK, 4FSK, 8FSK, 16QAM, 32QAM, v.29, OOK, 4PAM, Manual Morse, Machine Morse, and Noise (contact factory for additional modulation types.)

Where is the C-QUAM? WHERE is it? Sure, HFDF is nice, well, its really, really nice, but unless you're DF'ing in glorious AM stereo, what's the point? 



The noise modulation type trumped the cquam, too spendy for the fedz to pop for the cquam and noise both.
We do not encourage any radio operations contrary to regulations.

 

HFUnderground T-Shirt
HFUnderground T-Shirt
by MitchellTimeDesigns