Quick Login

Author Topic: QRM on 3579.5 all night long  (Read 602 times)

Offline ve3lyx

  • Commodore
  • *
  • Posts: 159
  • Country: ca
QRM on 3579.5 all night long
« on: October 12, 2015, 13:31:17 UTC »
Last night I checked into 3579.5 with my one transistor rig. I gave a QRL & backed it up. Nothing heard so I called CQ. During about my third call I heard a carrier come on. Quite strong and a quick ID and away they went. Kind of a musical note. da da do da  kinda thing and there would be a rest and away they go again. I should  I guess but I don't know what that is. I live near a mililtary transmitter site (about 10 miles from) and I know they sometimes use Ham bands when they feel like it (for communicating with ALERT so I have been told) but I am not totally sure that is what this is. It was still going this morning for a bit then quit. At first it seemed right on freq but seemed to move up a bit. Sure is annoying since many of us pisqueak operators use the Tv colourburst freq for fun stuff on QRP. If anyone os familiar with this and can give me a heads up as to what it is I would like to know. Seems they come on just when I want to operate, usually weekends.
don VE3LYX

Offline ve3lyx

  • Commodore
  • *
  • Posts: 159
  • Country: ca
Re: QRM on 3579.5 all night long
« Reply #1 on: October 13, 2015, 11:33:59 UTC »
Surely I am not the only one who can hear this.
don VE3LYX

DF5WW

  • Guest
Re: QRM on 3579.5 all night long
« Reply #2 on: November 12, 2015, 17:28:14 UTC »
Hi Don,

i think you have heard JT-65 transmissions. The K1JT Software WSJT-X can decode JT-65 ans JT-9 signals if you set your trx to 3576 (JT-9) or 3578 (JT65) as dial frequency in USB .....

The K1JT software has "occupied" this frequencies in the 80 m band  ;) ;)

The melodic transmission is JT-65, JT-9 is more a verry small audio signal and you can´t hear so much changes in the NF frequency as in JT65 ....

For decoding tests connect your transceivers audio out to the microphone input of your soundcard and setup the software to this audio port. For transmit and receive its better to use a digital soundcard modem like a signalink USB or equivalent .....

I have experimented with all the different digital modes and it´s nice to see what distances are possible with power below 5 watts .... but also there are "crocodiles"  with 50 or more watts power   ???