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2395RE: Re: [O_P_E_R_A_] RE: JA1ODJ >> KL7L Alaska 3461 Miles 136 KHz , -37 dB s/n 5%Fade

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  • graham787
    Nov 6, 2013


      No the  mode is  in use  from  audio to  light  , usage  may be  tracked  with the  psk-reporter , usage on the  lower  bands is  notable as  the  on/off keying  and  low  s/n  offers a alternative to the  traditional qrss system , and  provides  accurate s/n (average) and  fade pattern as  % along the  time  lime . OP32 lower decode limit is  round  -40 dB s/n [ref to path-sim] with the  advent  of the  73Khz  band  OP64  -43 s/n   was  added  to the  range and  linked  to the  psk-reporter  as  4000 meter's,

      A combination of  AFC/FEC  and  noise limiting  provides  excellent results  in difficult  circumstances , using  only  'normal'  Ham band  equipment   , the  shorter 30 second / 60 second  modes  provide good  scatter  propagation  on vhf/uhf  , the  afc  tracking  aircraft Doppler 

      136 activity increases during  the  winter  months (northern) at the  moment  Pacific stations are achieving

      quite  substantial range  with  limited power levels  and  Ae  systems , the  modes  immunity  to Doppler  spread  makes it  very suitable  for propagation via   polar path    where spreading  disrupts  mfsk/fsk 


      ---In O_P_E_R_A_@yahoogroups.com, <bcarling@...> wrote:

      Question - is OPERA only used on the 136 kHz band?

      On 4 Nov 2013 at 14:15, g0nbd@... wrote:

       Up to  -32 dB  now  !

      Rx at Mon, 04 Nov 2013 13:19:46 GMT
      From JA1NQI in Japan
      Loc QM05DV by KL7L
      Distance: 3444 miles bearing 272°
      Frequency: 0.136 MHz (2200m), OPERA, -32dB

      ---In o_p_e_r_a_@yahoogroups.com, <g0nbd@...> wrote:

      Dont think you  can  do  much better  than  a  mini-whip , its all  down to  local noise , I think  some  of the  JA stations  have  remote systems , the  other  view is  all  that  wire  could  be  radiating  on 136 , by  coupling  ?


      ---In o_p_e_r_a_@yahoogroups.com, <wd4rbx@...> wrote:

      Hi G,
      TNX  for the links. Lots of interesting equipment at LFengineering. I'm wondering about there preamp for VLF/LF. This is what I'm thinking. Build the DK7FC VLF active E probe circuit and use their preamp or simply use their preamp and add a 4 to 1 audio transformer for second output connection to a sound card for the Dreamers Band RX? I'm wondering  if this setup would be any better then DK7FC  circuit?
      Are you kidding me...? I Hope the JA  station picture is just an optical allusion. Look at all those mains wires. I would be afraid to stand next to his tower much less climb it. How on Gods green earth does he hear anything @ 136 KHz? You go dude..!

      From:  "g0nbd@..." <g0nbd@...>
      To: O_P_E_R_A_@yahoogroups.com
      Sent: Friday, October 25, 2013 3:49 PM
      Subject:  RE: Re: [O_P_E_R_A_] RE: JA1ODJ  >> KL7L Alaska 3461 Miles 136 KHz , -37 dB s/n 5%Fade
      Tx station  details 


      Carrier 200W  specifies  power  as 100W (50% duty cycle). 

      Good contact  with  manageable  'safe' power levels  !


      ---In O_P_E_R_A_@yahoogroups.com, <o_p_e_r_a_@yahoogroups.com> wrote:
      I wonder what kind of antenna he's using?

      From: "g0nbd@..." <g0nbd@...>
      To: O_P_E_R_A_@yahoogroups.com
      Sent: Friday, October 25, 2013 12:24 AM
      Subject: [O_P_E_R_A_] RE: JA1ODJ >> KL7L Alaska 3461 Miles 136 KHz , -37 dB s/n 5%Fade

      ---In O_P_E_R_A_@yahoogroups.com, <o_p_e_r_a_@yahoogroups.com> wrote:
      JA1ODJ >> KL7L Alaska 3461 Miles 136 KHz ,  -37 dB s/n 5%Fade F irst JA/USA decode  using  OP32 on 136KHz ,  [no details  of tx station yet] 73-G,

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