Apparently little known fact:
If you are 80dB down from a 27 watt signal you are transmitting 0.027
watts
BFD
73 W9OY
___
FlexRadio Systems Mailing List
FlexRadio@flex-radio.biz
I was going to say this perfectly demonstrates both the great power
(sensitivity) of the panadapter and our greatest curse at the same time.
I was going to give my usual long winded commentary but I must admit
that your 3 letter comment is right to the point.
There are design compromises in
On Tue, Feb 2, 2010 at 12:19 PM, Brian Lloyd brian-wb6...@lloyd.com wrote:
It appears to me to be
aliasing products which make me suspect sample-rate conversion used in
either fldigi, dm780, VAC, PowerSDR, or some combination thereof.
True--it's not a harmonic. When the PSK31 signal is at the
On Wed, Feb 3, 2010 at 2:57 PM, Joe Knapp jmkn...@gmail.com wrote:
On Tue, Feb 2, 2010 at 12:19 PM, Brian Lloyd brian-wb6...@lloyd.com wrote:
It appears to me to be
aliasing products which make me suspect sample-rate conversion used in
either fldigi, dm780, VAC, PowerSDR, or some combination
At 05:13 PM 2/3/2010, Brian Lloyd wrote:
Yes. Do you remember me saying, it appears to be an aliasing product
of the sample-rate conversion, back at the beginning of this thread?
Remember, if you have sampled at 96kHz the Nyquist frequency is 48kHz.
When you resample to 48kHz the Nyquist
Random thoughts:
You shouldn't have any spurs, that's it. Even though the spur is ~60dB down
on the main signal it'll be easy to decode and just shouldn't be there.
As Tim says it could well be a soundcard harmonic *but* you're using VAC, in
which case it would have to be generated inside the
Simon this is what I have
Vac Settings PowerSDR settings
http://www.slhess.com/pictures/VACsetings.png
I set it up from this KC article.
How to Setup Virtual Audio Cable (VAC) 4.0x with PowerSDR 1.x
http://kc.flex-radio.com/KnowledgebaseArticle50230.aspx
On 02/02/2010 01:17 AM, Simon HB9DRV
OK,
I see you're connecting PowerSDR to the VAC at 48kHz and DM780 / Fldigi at
8kHz.
So the VAC driver will have to convert the data, I'll bet it's this logic
which is causing the spur (note - I am often very wrong).
I don't have any Flex radios at the moment so can't try my idea but I would
Yuck!
Looking at your screenshot again - the VAC Control Panel window - you're
going to have all sorts of rate conversions running, your cables are using
44,100 as their sample rate.
I would use a sample rate of 48,000 or 8,000 and *not* have the cable
running internally at 44,100, essentially
Simon
Dropping the sample rate to 4100 in the PowerSDR set up for VAC
eliminated any Spurs visible in fldigi.
From quickly reading the VAC documentation I didn't grasp how I would
change the sample rate from 4100 to 4800.
As my primary audio sample rate is 48k I attempted to match the VAC
On Tue, Feb 2, 2010 at 7:11 AM, Steven L Hess sh...@bak.rr.com wrote:
From quickly reading the VAC documentation I didn't grasp how I would
change the sample rate from 4100 to 4800.
As my primary audio sample rate is 48k I attempted to match the VAC
PowerSDR setting to the same audio sample
Yes Joe and the DM780 signal is even cleaner it appears to me to be much
narrower and not in need of any filtering. The apparent width of the
fildigi signal is about 3X wider in the panafall
The trick to get rid of spurs if you have them is the going from 4800 to
4100.
On 02/02/2010 05:13 AM,
I believe the VAC sample rate is set by the first program to open the
VAC. If you fire up PowerSDR enable VAC then start your digital
program, your VAC will be set to the PowerSDR VAC sample rate --
learned the hard way...
Joe Knapp wrote:
On Tue, Feb 2, 2010 at 7:11 AM, Steven L Hess
You are correct, Dave. That is why it is best to start PowerSDR first and
enable VAC before starting the digi mode program so that PowerSDR can establish
the cable parameters (sampling rate and bit depth).
-Tim
-Original Message-
From: flexradio-boun...@flex-radio.biz
On Tue, Feb 2, 2010 at 1:17 AM, Simon HB9DRV si...@hb9drv.ch wrote:
Random thoughts:
You shouldn't have any spurs, that's it. Even though the spur is ~60dB down
on the main signal it'll be easy to decode and just shouldn't be there.
As Tim says it could well be a soundcard harmonic *but*
Converting between 8kHz and 48kHz should not be problematic but between
44.1kHz and 48kHz will be a problem unless it's correctly encoded.
there are some good routine in the public domain and also the Intel IPP
libraries have excellent sample rate conversion.
Simon Brown, HB9DRV
Hi Simon,
You are righ on this.
My VAC SR is on 44100 allways, and does not shange if I start DM780 or
PowerSDR first
Have tryed to change SR in PowerSDR first an then start is, but VAC is still
on 44100
So it looks like VAC is fixed on 44100 for some reson.
Then I can se that DM780 is running
Hi,
No.
Simon Brown, HB9DRV
http://sdr-radio.com
-Original Message-
From: Jan Egholm [mailto:j...@egholm.fo]
Sent: 02 February 2010 19:12
So my questions is if there is a way to force DM780 to 41000?
___
FlexRadio Systems Mailing
No,
DM780 opens the output device (Soundcard, VAC) at 8kHz. Surely you can set
the VAC to use 48kHz (8kHz * 6) PowerSDR at 48kHz?
You do not have to use the same rate at each end of the VAC - the driver
will convert the sample rate (with a little help from Windows).
I really don't want to
I didn't realize that DM780 opened the VAC at 8kHz-- Not a problem..
I've been using DM780 for about 2 years.. I've always kept the PowerSDR
sample rate at 48000.
So as long as PowerSDR opens the VAC at a sample rate that is a multiple
of 8kHz all will be well.
Definitely preserve your brain
Hi Steve,
Try DM780 (HRD) and you can see what Tim is talking about, it doesn't have
the sound card harmonic and is NOT a Flex issue.
It is there with any other Radio you run FLDIGI on, the difference from
other Radios is, with the Flex / PowSDR YOU CAN SEE IT.
73's
Bret
WX7Y
Thanks Tim and Bret
I am glad its not a problem with the rig. I will email the author of
fldigi with a URL pointing him to the image.
I have HRD 5 installed and configured and will play with DM780 once I
get it configured so DM780 can talk to the HRD and the rig. Too many
irons in the fire this
That was with no RF out it bumps up to about -80 on the display with 17
watts out displayed under fldigi. DM780 has a spurs too. -100 on the
display with 26 watts out on the display at 14.070. -80 on 7.035 with 21
watts actually on the air. I guess I am just overly concerned with what
I can see.
I don't see a filter as a solution as it defeats the purpose of how
PSK31 software works. You could be constantly modifying your filter where you
should just be selecting a frequency with your mouse. Since radio is better the
software needs to be better too.
You have to get clever with how you
On Mon, Feb 1, 2010 at 8:37 PM, Steven L Hess sh...@bak.rr.com wrote:
That was with no RF out it bumps up to about -80 on the display with 17
watts out displayed under fldigi. DM780 has a spurs too. -100 on the
display with 26 watts out on the display at 14.070. -80 on 7.035 with 21
watts
Hi,
I am using DM780 and have allways had this spur when running PSK
73,
Jan, OY3JE
Sent from my iPhone
On 02/02/2010, at 01.54, Bret Mills bmil...@ecso.com wrote:
Hi Steve,
Try DM780 (HRD) and you can see what Tim is talking about, it
doesn't have
the sound card harmonic and is NOT a
26 matches
Mail list logo
