Hi Rein,
Actually I just plug my SoftRock into the USB socket on the front of
my Dell 2400 machine. The little receiver plays quite nicely that
way and others have had the same results with various computers. As
I write this, I have a SoftRock playing on the same PC. Forty
meters this morning at my QTH shows a flexuating base noise level of
about -122 dBm and the peaks of the soundcard related spikes are
visible to about -118 dBm. S5 signals are at about -110 dBm. Tuning
around I find an S3 signal that is still good copy.
I continue to be amazed at how well PowerSDR software and a simple
receiver circuit work together to make a nice little receiver.
73,
Tony KB9YIG
--- In softrock40@..., "Rein A. Smit" <rein0zn@i...>
wrote:
Hi Tony,
Thanks for your reply. From looking to the picture on one off the
softrock pages
I got the idea that the board was directly plugged into an USB
connector
of the
computer. Looking more careful it seems the board is running from
an USB
cable connector?
My question was more in general, not softrock specific. I was
surprised
to see an unshielded
front-end that close to a PC
I have been playing quite a bit with Linrad Spectran dspblaster
etc just
running off a TS 850 at least
30 ft from the PC and I get all kinds of stuff from the computer.
In
fact it means that I will have to
put the computer in a second box with all inputs and outputs well
decoupled I think. This is just
monitoring basically antenna noise.
I am expecting a board shortly and will let you know, using the
Delta44
sound card.
73 Rein W6/PA0ZN
kb9yig wrote:
Hi Rein,
I have built about 25 of the v4.0 SoftRock40 receivers and find
the PC
noise does not cause much of a problem. When the receiver is
calibrated to S9, (-73 dBM, 50 uV RMS), the baseline is around -
135
dBm with 10-15 dB spikes riding on the baseline every 1 kHz or
so.
Also at the LO frequency, around 7.054-7.056 MHz there is a large
broad spike associated with the LO and the fact that the
soundcard
contributes lots of noise near zero frequency.
I will be quite interested in the experience of SoftRock40
builders as
they finish their kits. If I can help with problems in getting
the
little receive running, I would be happy to do so.
73,
Tony KB9YIG
--- In softrock40@..., "observer35" <rein0zn@i...>
wrote:
Hi all,
Just new to the group.
Does anybody experience interference from the PC on 40 meters?
What about noise and garbage on the 5 V USB line?
73 Rein W6/PA0ZN
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