Hugh,
yes , your seeing the average s/n of the 32
min Tx , either decode or detection , the recovered s/n
is the same calibration ..as is the reported audio
frequency , the average of the Tx / 32mins
for op32
By + 10 dB in hand , that simply intimates,
the Tx power could be x 10 less -10 dB , before
the bottom of the system is reached
Not a 10 db pad in the rx line , that would reduce , say
a spec-lab plot.
The question is , ''What exactly is the point of
Opera'' ?
Simple , its a engineering tool to validate the
path's ability to support a DATA transmission ,
the % fade is set at + 3 dB from the
system lower limit , that equates to the fade
margin , which, links to the level of FEC needed
etc , in this form a 'beacon' [version 1-4-1
contains a -20 dB s/n 15 chrs plain text mode] ,
unique.
Once the system changes to the Dynamic detector [
correlation] Dynamic , in that its configured automatically ,
past the lower limit of the op32 / op8 data
decode, then the Tx time line is evaluated as a
single data 'BIT' against the stored pattern In this
case, a call sign list , unlike the minimum of 40% recovered
data bits , needed for a decode..., hence no % fade ,
its a go-no go test . the spot time of
other stations is used to validate , as false spots , always
have valid calls ...
eg .set of 4 correlation detections and 1 data
decode , the decode could provide validation , or the
coincident deep-search time stamps .
23:18 136 RN3AGC de RW3ADB Op32 21 mi -25 dB F:0% in
Moscow 1535,8 Hz
23:23 136 RN3AGC de RA3TGZ Op32 Deep Search 235 mi -41 dB in Sarov 1536,4
Hz
23:23 136 RN3AGC de RA1ADF Op32 Deep Search -41 dB in St.Petersburg 1533,4
Hz
23:23 136 RN3AGC de SP5XSB Op32 Deep Search -41 dB in Raszyn nr Warsaw
23:23 136 RN3AGC de SM2DJK Op32 Deep Search -41 dB in
Umea
This is only provided on the 136 and 477
bands , where signals are inherently low , all
other's remain 250 bit serial data decodes , including
the Op1H Op2H op4H used on bands below 136K
73-Graham
Sent: Sunday, August 14, 2016 8:59 PM
Subject: Re: LF: last 23 Hr 136 op32
Ask me who set 10db attenuation on his radio as well! As it's s/n
ratio we're looking at it shouldn't make too much difference. There is also an
obstacle, a 60m limestone cliff some 400m behind us in the NW direction, rising
to about 280m.
Hugh, M0DSZ
On 14/08/2016 19:43, Graham wrote:
M0DSZ & G3XDV Decoding VO1NA last night ,
impressive signal levels , 10 dB in hand
R7NT Peaking at -34 , G3XDV , also +
10 dB
73-G,
|
2016-08-14 02:33:07 |
R7NT |
KN97LF |
G3XDV |
IO91VT |
2.837 |
136 |
-40 |
Op32__~40dB |
|
2016-08-14 01:33:07 |
R7NT |
KN97LF |
G3XDV |
IO91VT |
2.837 |
136 |
-34 |
Op32_||||||||_~34dB |
|
2016-08-14 00:33:06 |
R7NT |
KN97LF |
G3XDV |
IO91VT |
2.837 |
136 |
-38 |
Op32__~38dB |
|
2016-08-14 04:35:17 |
VO1NA |
AA |
M0DSZ |
IO82LS |
0 |
136 |
-33 |
Op32_||||||||||_~33dB |
|
2016-08-14 04:00:03 |
VO1NA |
AA |
M0DSZ |
IO82LS |
0 |
136 |
-35 |
Op32_||||||_~35dB |
All spots showing on psk-map
