I came to a similar conclusion last night, the radio was acting like it's RF gain was way down. I discovered that by turning up the AGC gain I could hear the crud between signals. At first I turned it way up, but after a while it got old hearing all that noise, so I started turning it down a little bit at a time, until I arrived at a value that would let me hear weak signals yet barely hear the constant crud.
That is a pretty nice feature, I have a FT-817 and one of it's failings is that the AGC cranks up the gain so high when there is no signal, that it drives crazy with all the noise. I resort to manual gain and you get a much nicer result.
I've been playing with the settings on the software and cranked up the DSP buffer to 2048, that makes the filters really much sharper, yet it doesn't seem to eat too much more CPU time. The two displays are the ones that eat up the CPU.
One more question; the ASIO4all has setting for using DMA for the transfers, I have not seen anything on it, it seems to cut down CPU usage by a few %, Is this recommended, using DMA on the sound card transfers?
Thanks
At 03:31 PM 9/25/2005, you wrote:
Cecil,
The wave files as recorded by the PowerSDR software does indeed take the raw
audio straight from the radio and record it wideband (on RX -- it takes post
filtered data on TX). What you are noticing is that the AGC is setup
correctly for your system. This means that when a signal is not present, it
doesn't add too much gain amplifying the noise.
You can change the threshold for the max gain on the DSP tab of the setup
form. Notice that if you raise it as high as it will go, you will be able
to hear the noise. This is what you try to avoid especially in contests as
it is fatiguing to listen to.
Note that the flipside of this is that if you can't hear the noise, you
probably won't be able to hear a really weak signal near the noise floor.
So use your settings carefully.
This is just one of the many ways that we can adapt software to perform just
like the doctor (or the customer) ordered.
Eric Wachsmann
FlexRadio Systems
SNIP
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Cecil Bayona
KD5NWA
www.qrpradio.com
I fail to see why doing the same thing over and over and getting the same results every time is insanity: I've almost proved it isn't; only a few more tests now and I'm sure results will differ this time ...
