Hi Chris,
As I go through test on the SoftRocks I am building for people, I find image null from unit to unit is fairly uniform. It does take a little adjustment each time to get the best image rejection as I go from one unit to the next. Changing soundcards would probably require a change in the image null adjustment. What I typically see using a mother board soundcard in my PC is a phase slider setting around -100 and a gain slider setting near zero to null the image. I wonder how that compares to what others are seeing?
The SDR-1000 includes an impulse generator circuit on the RFE board. PowerSDR software changes in the future will include an automatic image null feature. This could be done on a receiver as simple as the SoftRock also.
Tony KB9YIG
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----- Original Message -----
From: "Chris Waldrup" <kd4pbj@...>
To: <softrock40@...>
Sent: Monday, October 10, 2005 9:30 PM
Subject: Re: [softrock40] Version 5 SoftRock, anyone?
Hi Tony,
Yes I would like one as well.
One thought came up today at work... is the image nulling setting dependent
on the softrock used or can I use any softrock once I get it nulled? I
didn't know when I get my other softrock built if I need to go through the
nulling or not or if it is once per soundcard.
Chris
KD4PBJ
----- Original Message -----
From: "Bruce K3CMZ" <k3cmz@...>
To: <softrock40@...>
Sent: Monday, October 10, 2005 10:06 PM
Subject: Re: [softrock40] Version 5 SoftRock, anyone?
Hi Tony
Count me in for the Two Board Unit.
Might need an Mute Circuit and Antenna Relay!
Here we go again, another 1000 kits!
Bruce K3CMZ
On Tue, 11 Oct 2005 01:28:51 +0000, you wrote:
Hello Everyone,
I am working on a version 5.0 of the SoftRock receiver and want to
see if there is interest enough to do a kit. The version 5.0
SoftRock oscillator will be at the fundamental frequency and depend
on 90 degree phase shift network to generate the quadrature clocks
for the QSD. This should give more flexibility in finding suitable
crystals for various bands.
The version 5.0 will consist of a two board stack with each board
having dimensions about 1 inch by 1.5 inches. The bottom board of
the stack with have a 5 VDC regulator, two voltage comparitors, the
QSD circuit and the low noise audio amplifiers. The upper board
will contain the oscillator circuit, the 90 degree phase shift
network, and the BPF for the desired band. The two boards will be
joined electrically by a row of header pins on the top board and the
corresponding sockets on the lower board. A threaded standoff
between the two boards will provide for mechanically holding the
upper board to the lower board. Corner mounting holes will be
provided on the lower board.
External electrical connections to the lower board will include,
supply voltage (9-12 VDC), an antenna input and a stereo audio cable
for line-in connection to the PC.
Target kit price is in the mid-twenty dollar range for one set of
boards and components for a single band. Additional band kits might
be on the order of $12 each with 80 meters through 30 meters and
possibly 20 meters also covered.
Please let me know if there would be any interest in such a kit.
Thanks and 73,
Tony KB9YIG
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