Wednesday, June 30, 2010

QRT for a while (please help!)

At the location of the Suburban Subharmonic Grabber, generation of electro-magnetic fields is ceased temporarily. This includes the local oscillator of the subharmonic direct conversion grabber receiver(!). BTW: WLAN is shut down too, for the time being.
I hope that I will be able to provide grabber-services again, sometime.
It seems that, nowadays, spectrum grabbing is a suspicious activity!!! Oh, and... it seems that even writing about ham-radio is dangerous!!!
In order to support my "case", please feel free to write some comments to this post.
With your help, people may understand that what we are doing is just a matter of fun and helps studying propagation phenomena.


  1. well, i understood the grabber thing, you're looking for really low power stuff, so you have to watch the radio for a long time with special equipment. some people fear what they don't understand, but if it bothers them it is their loss. not sure what all is up, but if you've been disconnected by a company, that seems kind of crappy. anyway, i'm just beginning with radio stuff, and meant to dig deeper into your SDR schematics, but wound up building some kind of direct conversion thing i think in the meantime, but good luck to you, and hope you still find interesting things no matter what your situation. best of luck!!!

  2. Dear Joachim, could you explain a little bit more about the shutdown of your grabber ? Is it the internet provider who has objections ? Or is it the neighbourhood? I enjoyed watching my 100mW signal on your grabber lately and it would be a loss if the grabber will stop operation.
    73 Ron

  3. First of all, many thanks to highfidelitytom!
    Tom, your understanding fits 100% with mine. And yes, some (many) people fear what they don't understand... that exactly is my problem. Fingers crossed I will leave the scene with minor bruises only.

    Ron, well, I can tell that neither my neighborhood, nor my internet-provider are causing any troubles... Yes, that sporadic E we recently had was enormous!

    73 Joachim

  4. Dear Joachim,
    It's still a mystery to me.
    Anyway, how can we help you

    73 Ron

  5. My Dear Joachim,
    What on earth has happened? For the life of me I cannot understand why anyone would object to our grabbing activities. Perhaps I have just been lucky, but in the nine months since I started mine running the only complaints I have had are where fellow amateurs have failed to spot their own signal. I follow Ron (also a nice guy) in saying "How can we help?"

    Very best wishes,
    Andrew, G4CWX

  6. Geachte Ron, dear Andrew,
    with posting comments, the both of you helped already!
    Thanks a bunch my friends!
    73, Joachim pa1gsj/dl1gsj

  7. Could I get a leg up? I am a CS major with some military experience and am totally interested in information propagation and degradation theory. Any leads on quaternion mathematics you would like to share? Hit me up @

  8. Joachim,
    What is all this about. I understand the shutdown, but not the reason why. Is there anything I can do? I work for ISP's and have a good knowledge of people therein.

    Please elaborate, since the information you give is very little.

    73 Ed PE5ED

  9. guys, thank you so much for you support! it got me back only, firing up the grabber again and start writing about my present ideas.

    i can't tell you how blessed i feel to have support like yours!

    73! Joachim