Max SNR as Indicator of RX Performance?

[df9rb]

Hi Tom,

during reading your post I logged VoR. So fast you won your bet!
Peak SNR today was 44.5 dB with the DRT1
As DRM technics is continuously improving on transmitter and
receiver side I propose (or even bet 1 Dollar or so) that the 50 dB-limit will have been exceeded in 3 years on over the air signals.
- hsseppo reached 51.4 dB direct from TX
-my 96 kHz/24 bit soundcard with modified Dream for 96 kHz sampling rate is good for more than 60 dB SNR
- my DRT1 reached 47 dB direct from TX, with the limiter during this test beeing very likely the used up-mixer

Bernd, DF9RB

[df9rb]

Hi all,

44.5 was not the end today. During the transmission from Taldom on 15780 kHz in German SNR climbed up to 45.1 dB.
I used this excellent condx to compare between Dream with 48 kHz sample rate and the modified version for 96 kHz. The result is marginal: under rough conditions no better decoding with 96 kHz; up to 40 dB no difference, above 40 dB the SNR with 96 kHz sampling rate is 0.1 better to 0.2 dB at 45 dB. The soundcard is a Sound Blaster Live! 24-bit. The CPU load is very high however even with the AMD 3400+ running Dream and sound card in 96 kHz/ 24 bit.

Bernd, DF9RB

[VE3MEO]

Re: Re: Max SNR table - the ascent to 40dB AND BEYOND!

Here are the latest changes to the table.

73, Tom

With the surpassing of the 40dB mark, Carsten has revised the ceiling of the graphical scale on his excellent DRMcalc software to 44dB. I'll bet that's surpassed this winter! DF9RB has come within a 1/2 dB.

No sooner said than done!

Oct 16: Bernd, DF9RB, leaps past the DRMcalc 44 dB ceiling with a peak of 45.1 dB!

One wonders what the ionosphere looks like when such excellent results are obtained. Is it like a mirror in the shape of a modified ellipsoid, static in elevation so there is no doppler or jitter, with the transmitter and receiving locations at equal distance for all paths, so there is no impulse spreading?

Oct 7: Carsten puts the Coding Technologies DWT into the table for the first time with 32 dB.

[simone]

Hi Tom,
I had e mailed you in June about the DWT, I think the best until now was this one:

http://www.drmrx.org/forum/attachment.php?postid=19030

Simone

[VE3MEO]

Re: Re: Re: Max SNR table - the ascent to 40dB AND BEYOND!

Here are the latest changes to the table.

73, Tom

Earlier report over 30 dB for the DWT:

July 24: Simone's best of 33.2 dB (sorry for missing this, Simone)

[VE3MEO]

Re: Max SNR table - the ascent to 40dB AND BEYOND!

Here are the latest changes to the table.

73, Tom

2005-12-31 35.9 dB by johnn, Scunthorpe, N.Lincs, UK DRT-1
2005-11-02 33.0 dB by Digger, CH-5023 Biberstein FRG7700
2005-10-29 33.5 dB by johnn, Scunthorpe, N.Lincs, UK AOR 7030

[Han]

Best SNR

Hello everyone

I also had a quite good result
It is my best result sofar.
Sines gives me the best results most times

Receiver AOR 7030 with 455 to 12 kHz converter SAt schneider
Dream 1.5 antenne : ALA 1530

Best Dx

Han
The netherlands

[johnn]

Hello Han,
A good result that!

[Han]

Hello John

Thank you for thr reply!
I also found it a very good result, sometimes the SNR is a few days higher than normal.
I get the best results on my loop antenna, it gives a better result then my T2FD. On AM the T2FD sound most of the time better.

I think that is strange.

The best results I get from Sines, the SNR is mosttimes above 30 dB

Greetings Han

[Saulius]

Shifted PSD

Greetings

May be interesting info about my IQ DRM Decoder and
minimal Shifted PSD by Dream

http://drm.sourceforge.net/forums/index.php?showtopic=156&st=0&#entry874

Best regards

Saulius

[Funkerberg]

35,9 dB SNr / 5810 kHz / DW

This is my best result so far.

Receiver : Elektor
antenna : selfmade 10 m Dipol
QTH: Königs Wusterhausen / 20 km south of Berlin / Germany

many greetings Rainer

[Digger]

Hi,

Still not the best but a personal best. The FRG 7700 with a 7808 in the Vcc supply helped a bit. Using an external 17 Volt DC power supply instead of the receiver's AC / DC supply improved SNR considerably. Some level adjustment into the S042P on the IF side brought some improvement too. The last change (so far) was the 10 µF capacitor for slow AGC that got another 47 µF in parallel.

This morning I listened to DW on 13810 kHz and got a max. of 34,2 dB SNR.

Dream
Software Version 1.5cvs
Starttime (UTC) 2006-04-05 08:08:09
Frequency 13810 kHz
Label Deutsche Welle
Bitrate 17.26 kbps
Mode B
Bandwidth 10 kHz

MINUTE SNR SYNC AUDIO TYPE
0016 30 150 1500/10 0
0017 31 150 1500/10 0
0018 33 150 1500/10 0
0019 34 150 1500/10 0
0020 33 150 1500/10 0
0021 33 150 1500/10 0
0022 34 150 1500/10 0
0023 34 150 1500/10 0
0024 34 150 1500/10 0
0025 32 150 1500/10 0
0026 33 150 1500/10 0
0027 32 150 1500/10 0
0028 32 150 1500/10 0


SNR min: 4.9, max: 34.2


Terje

[VE3MEO]

Re: Max SNR table - the ascent to 40dB and beyond!

Highest SNR's over 30 dB achieved with DRMRX/DReaM

This is a listing in descending SNR of reported Max DRM SNR as logged by DRMRX and Dream software, and analysed by Carknue's DRMcalc. It's for fun but might yield some useful tips for better reception. If you have results that leap the 30 dB hurdle, e-mail me with the details and I'll add it to the list. 40 dB off-air SNR has been surpassed!

Most recent entries have dB in bold.

73, Tom
<table align=LEFT border="1">
<tr><th>Max SNR
<th>By
<th>Receiver
<th>Converter
<th>App
<th>Antenna
<th>Service
<th>Freq(kHz)
<th>Date</th>
<tr><td>51.4 dB
<td>hsseppo, Helsinki, Finland
<td>AD8099, AD9551, AD831, 21.4 IF
<td>AD831
<td>DReaM 1.2.5c
<td>Direct from Tx
<td>Dream Test
<td>10012
<td>2005-06-30
<tr><td>48.3 dB
<td>mitajohn Athens, Greece
<td>Sat-Schneider DRT1
<td>
<td>Dream 1.6.1 cvs
<td>Dream -t burnt CD played into SA602 up-mixer
<td>test
<td>1000
<td>2008-02-09
<tr><td>48 dB
<td>DRM-OM (Bernhard), 25km SE Karlsruhe Germany
<td>Sat-Schneider DRT1
<td>
<td>Fraunhofer IIS software radio V4.0.40
<td>Direct from Tx
<td>Test
<td>6000
<td>2006-04-24 German, English Translation
<tr><td>45.1 dB
<td>Bernd DF9RB 150 km n. of Munich, Germany
<td>Sat-Schneider DRT1
<td>
<td>DReaM 1.3.1cvs
<td>3-el ham Yagi, ALA1530, 30m wire or EWE
<td>Voice of Russia
<td>15780
<td>2005-10-16
<tr><td>42.1 dB
<td>René Schmitz, Bonn, Germany
<td>Elektor custom IF, ADA831 2nd mxr, TUF-1,1st mxr preselector
<td>
<td>DReaM 1.1.6c
<td>5m wire
<td>DW Sines
<td>11830
<td>2005-02-05
<tr><td>42.0 dB Euro bonus
<td>FritzWue DK6QI 52N 07E
<td>Sat-Schneider DRT1
<td>
<td>DReaM 1.6.1cvs
<td>80m dipole up 20m
<td>DW
<td>13810
<td>2006-09-09
<tr><td>41.2 dB
<td>Bernd DF9RB 150 km n. of Munich, Germany
<td>TS850 AGC inactive
<td>SA612 ceramic resonator
<td>DReaM 1.1.7c
<td>3-el ham Yagi, ALA1530, 30m wire
<td>Voice of Russia
<td>15780
<td>2005-01-31
<tr><td>40.6 dB
<td>DG9BFC, Barenburg, Germany
<td>IC-765 manual gain
<td>Sat-Schneider xtal
<td>Dream 1.6.1cvs
<td>170m delta loop
<td>DW Sines
<td>13810<td>2006-09-26
<tr><td>40.4
<td>FritzWue DK6QI 52N 07E
<td>Flex-5000A
<td>
<td>DReaM 1.6.1cvs
<td>80m dipole up 20m
<td>DW Moosbrunn
<td>7310
<td>2008-04-19
<tr><td>40.3
<td>maxpower Oldenburg, Germany
<td>Pappradio dvlpd by Stephan
<td>
<td>DReaM 1.10.6cvs
<td>longwire
<td>DW Moosbrunn
<td>7310
<td>2008-07-04
<tr><td>40.0 dB
<td>df8uo, Karlsruhe, Germany
<td>FT757GX
<td>Sat-Schneider xtal
<td>Dream 1.3c
<td>dipole
<td>VOR
<td>15780<td>2005-10-03
<tr><td>39.1 dB
<td>Digger, CH-5023 Biberstein
<td>FRG7700 + Stabilock 4040 LO
<td>SO42P xtal
<td>Dream 1.6.1cvs
<td>16m LW + 1:1 un-un
<td>DW
<td>13810
<td>2006-09-23
<tr><td>39.1 dB
<td>mitajohn Athens, Greece
<td>Sat-Schneider DRT1
<td>
<td>Dream 1.6.1 cvs
<td>Inverted "L" 9V/16H m
<td>MOI Kuwait
<td>13620
<td>2008-05-11
<tr><td>37.9 dB
<td>simone, Bad Salzschlirf, Germany
<td>FRG100 AGC off
<td>Sat-Schneider
<td>DRMSWR 2.0.34
<td>whip
<td>DW Sines
<td>11830
<td>2005-02-08
<tr><td>37.8 dB
<td>Francois, Petite Rosselle, Fr.
<td>ELAD FDM77 AGC SW + SLOW
<td>
<td>Dream 1.6.1cvs
<td>Twin Zepp
<td>DW
<td>13810
<td>2006-11-17
<tr><td>37.6 dB
<td>hsseppo, Helsinki, Finland
<td>AD8099, AD9551, AD831, 21.4 IF
<td>AD831
<td>DReaM 1.2.5c
<td>5m wire
<td>VoR
<td>15780
<td>2005-06-30
<tr><td>37.5 dB
<td>Han, Netherlands
<td>AOR AR 7030 unmodified
<td>Sat-Schneider
<td>DReaM 1.5cvs
<td>ALA 1530
<td>DW Sines
<td>17700
<td>2006-01-21
<tr><td>36.5 dB
<td>CT1ADT, Sines, Portugal
<td>TS-870 unmodified
<td>11,3 kHz out
<td>DRM 2.0.34
<td>8m vert or 24m dipole
<td>VOR
<td>15780
<td>2004-01-07
<tr><td>36.3 dB
<td>carknue, Frankfurt, Germany
<td>AOR-7030 AGC off
<td>Sat-Schneider xtal
<td>DRMSWR 2.0.34
<td>Wellbrook ALA1530P
<td>DW
<td>5980
<td>2005-10-14
<tr><td>35.9 dB
<td>johnn, Scunthorpe, N.Lincs, UK
<td>DRT-1
<td>
<td>DReaM 1.5cvs
<td>AL1530 loop
<td>DW Sines
<td>17700
<td>2005-12-31
<tr><td>35.9 dB
<td>Funkerberg, Königs Wusterhausen, near Berlin
<td>Elektor
<td>
<td>Dream 1.6.1cvs
<td>10m dipole
<td>DW
<td>5810
<td>2006-03-04
<tr><td>35.6 dB
<td>arniek, Muenster, Germany
<td>FRG-100
<td>Sat-Schneider
<td>DReaM 1.1.1c
<td>homemade loop
<td>DW Sines
<td>5980
<td>2004-10-08
<tr><td>35.2 dB
<td>fibber - Salem, Oregon USA
<td>Yaesu FT-817, 10dB Radio Shack preamp, NCL MW Filter
<td>I5XWW 455k to 12k board
<td>Dream 1.6.1c
<td>80M Dipole
<td>RNW
<td>6130
<td>2008-02-07
<tr><td>34.9 dB
<td>dn0758
<td>elektor
<td>
<td>DRMSWR 2.0.34
<td>Sony AN-1
<td>DW Sines
<td>17800
<td>2004-11-20
<tr><td>34.4 dB
<td>chemclouds, Richmond, Va, USA
<td>Icom IC-R75 AGC off
<td>
<td>DRMSWR 2.0.34
<td>30m inverted-L
<td>CBC Sackville
<td>9800
<td>2004-11-27
<tr><td>34.3 dB
<td>FritzWue DK6QI 52N 07E
<td>FT840
<td>Sat-Schneider
<td>DReaM 1.1.6c
<td>2x 40m LW
<td>DW-Sines
<td>17800
<td>2004-12-18
<tr><td>34.3 dB
<td>Kjell Holen LA6XJ Bergen, Norway
<td>Sat-Schneider DRT1
<td>
<td>DReaM 1.1.7c
<td>70 cm indoor loop
<td>Voice of Russia
<td>12060
<td>2005-01-15 e-mail
<tr><td>34.2 dB
<td>Werner DK8FT
<td>IC R71 AGC off
<td>Sat-Schneider xtal
<td>Dream 1.1.6
<td>4m wire
<td>DW-Sines
<td>17710
<td>2005-02-20 not posted
<tr><td>33.5 dB
<td>johnn, Scunthorpe, N.Lincs, UK
<td>AOR 7030
<td>
<td>DReaM 1.2.4
<td>AL1530 loop
<td>Radio Luxembourg
<td>7145
<td>2005-10-29
<tr><td>33.2 dB
<td>G3VRF, Warwickshire , UK
<td>AD9852 DDS, AD831 Mixer, 2x AD603 IF
<td>12kHz DRM xtal ctld
<td>DReaM 1.1.6c
<td>35cm tuned loop in attic 11m a.g.
<td>DW Sines
<td>11830
<td>2004-11-24
<tr><td>33.2 dB
<td>simone
<td>Coding Tech DWT
<td>
<td>Dream 1.2.3cvs
<td>long wire
<td>Bouquet Flevo NL
<td>7240
<td>2005-07-24
<tr><td>32.5 dB
<td>Bob, St Albans UK
<td>AR88D (60 yrs young!)
<td>Sat-Schneider LC
<td>Dream 1.2.4
<td>Wellbrook LA5030 indoor loop
<td>DW
<td>13790
<td>2005-05-22</td></tr>
<tr><td>32.5 dB
<td>Tom VE3MEO Toronto, Canada
<td>Radio Shack DX-394A no AGC nor 2nd IF fltr
<td>LF-D6 filter/NE612 protoboard
<td>DReaM 1.1.1c
<td>G5RV
<td>CBC Sackville
<td>6140
<td>2004-10-19
<tr><td>32 dB
<td>carknue, Frankfurt, Germany
<td>Coding Tech DWT
<td>
<td>Dream 1.3.1cvs
<td>Degen DE31 Active Loop
<td>DW
<td>5980
<td>2005-10-07
<tr><td>31.2 dB
<td>DRM-OM, 25km SE Karlsruhe, Germany
<td>DRT-1
<td>
<td>Dream 1.6.1cvs
<td>Dressler ara100 active ant.
<td>Radio Luxembourg
<td>7295
<td>2006-04-25
<tr><td>30.7 dB
<td>simone
<td>FRG8800
<td>Sat-Schneider
<td>DRMSWR 2.0.34
<td>whip
<td>DW Sines
<td>15435
<td>2004-10-10
<tr><td>30.4 dB
<td>TimoHannes, Petäjävesi, Finland
<td>elektor
<td>?
<td>DRMSWR 2.0.34
<td>active
<td>DW Sines
<td>17800
<td>2004-11-14
</table> [/B]

[Digger]

Again, personal record SNR

Hi,

Same configuration as on the 5th April. Max. 38,5 dB SNR.

Dream
Software Version 1.5cvs
Starttime (UTC) 2006-04-10 07:17:46
Frequency 7265 kHz
Latitude 47°25'N
Longitude 8°05'E
Label Deutsche Welle
Bitrate 17.26 kbps
Mode B
Bandwidth 10 kHz
MINUTE SNR SYNC AUDIO TYPE
0010 33 150 1500/10 0
0011 34 150 1499/10 0
0012 34 150 1500/10 0
0013 37 150 1500/10 0
0014 31 150 1500/10 0
0015 31 150 1500/10 0
0016 33 150 1499/10 0

SNR min: 0.6, max: 38.5

Regards,
Terje

[VE3MEO]

Re: Max SNR table - the ascent to 40dB AND BEYOND!

Here are the latest changes to the table.

73, Tom

2006-04-10 38.5 dB by Digger, CH-5023 Biberstein, FRG7700 modified
2006-04-18 32.4 dB by fibber - Salem, Oregon USA, Yaesu FT-817