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Re: LF: 23:16 136 G6AVK de EB3FRN-1 Op32 Deep Search 725 mi -40 dB

To: <[email protected]>
Subject: Re: LF: 23:16 136 G6AVK de EB3FRN-1 Op32 Deep Search 725 mi -40 dB
From: "Graham" <[email protected]>
Date: Tue, 19 May 2015 23:00:35 +0100
Importance: Normal
In-reply-to: <[email protected]cal>
References: <[email protected]cal>
Reply-to: [email protected]
Sender: [email protected]
Hi Luis

The gain would be the same , 5 dB , but first it would need to be added and that's another story ... being dynamic , tx and rx stability would need to be higher as there is no afc , its possible a much higher s/n could be achieved , but that would require , complimentary high-stab hardware , dynamic is configured to use the same as the opera decoder ...
But, from the 136 Dx fade patterns , its possible OP2 H would
provide medium range DX on 136 , may not on the ultimate 'dx' path ,
which appears to show windows in the 30 min period , OP32 dynamic
may do the job .. but first , need a RX down there !
The s/n measurement hand over Opera > dynamic is linear , s/n average
along the time line
73-G,

--------------------------------------------------
From: "VIGILANT Luis Fernández" <[email protected]>
Sent: Tuesday, May 19, 2015 11:46 AM
To: <[email protected]>
Subject: RE: LF: 23:16 136 G6AVK de EB3FRN-1 Op32 Deep Search 725 mi -40 dB
Hi Mike

Op32 with dynamic search is a fantastic tool indeed. Despite of the "fantastic" false decodes from time to time ! But those can be easily discharged, specially when having local reports of the Tx station
I made an experiment comparing Op2H (no deep search) with Op32 and it
showed out that both modes perform very similar
The experiment was made transmitting with U3 consecutive frames in Op32
and Op2H. I'm using a mechanically adjustable
vertical antenna so trimmed it down in order to get just a signal hardly
decoded on my monitor QTH at 7Km
It is amazing to check how just a little of vertical antenna height
increase can boost the Tx signal ! :-)
I set the results in an small Excel you can get here
https://dl.dropboxusercontent.com/u/7162072/Docs/Pruebas%20Op2H%20versus%20Op32.xls
The question is .... What should be expected from a Op2H with Dynamic
Search ??
73 de Luis
EA5DOM



-----Mensaje original-----
De: [email protected] [mailto:[email protected]] En nombre de Mike Dennison
Enviado el: martes, 19 de mayo de 2015 12:16
Para: [email protected]
Asunto: Re: LF: 23:16 136 G6AVK de EB3FRN-1 Op32 Deep Search 725 mi -40 dB

Well, I am running around 400mW ERP (as stated on my Opera beacon) from a transmitter with 800W RF output giving 3,2A into an inverted-L 14m high with 5x14m parallel top wires. Antenna efficiency (assuming 80% tx PA efficiency) is 0.05%.
I imagine G6AVK is running a lot less - from the reports it must be about
70mW ERP which suggests perhaps 0.1% antenna eficiency. His successes show
how useful Op32 is.in producing reception at 1000km+ with that power
level.
Mike, G3XDV
===========

There  is  a  interesting  question  ..

Two  LF stations ,  quite  close , similar  times ,  Colin   running
80  watts  carrier  power..

 what    power / Ae  efficiency    difference     produced     + 7
 and  +8 dB  at the  Rx's  ?

73-G


Rx at Mon, 18 May 2015 00:34:21 GMT
From G3XDV by DF1VB/3 Loc JO31SK
Frequency: 0.136 MHz (2200m), OPERA, -33dB
Distance: 536 km bearing 91°


Rx at Mon, 18 May 2015 00:34:21 GMT
From G3XDV by EB3FRN-1 Loc JN01MC
Frequency: 0.136 MHz (2200m), OPERA, -32dB
Distance: 1194 km bearing 174°
Using: Opera v1.5.7/Rptr V1.6
Antenna: RX Op32



From: Graham
Sent: Monday, May 18, 2015 12:31 AM
To: [email protected]
Subject: LF: 23:16 136 G6AVK de EB3FRN-1 Op32 Deep Search 725 mi -40
dB


Just 80 watts , just on the   Op32 decode  limit ,  dynamic  with  5
dB  in hand ?

73-G,

23:16 136 G6AVK de EB3FRN-1 Op32 Deep Search 725 mi -40 dB in Montbrio
with .w + Bottom loaded Inverted L 11m x 21m

23:16 136 G6AVK de DF1VB/3 Op32 Deep Search 297 mi -40 dB in Dortmund
with .w + Bottom loaded Inverted L 11m x 21m











From: Graham
Sent: Saturday, May 16, 2015 12:36 AM
To: [email protected]
Subject: LF: 22:54 136 G6AVK de DF1VB/3 Op32 Deep Search 297 mi -41 dB
in Dortmund






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