Klaus:
I would look in this order as I see no problem with image rejection here
(Delta 44).
1) bad audio cable
2) sound card problem
3) Bad U2 (bus switch)
4) imbalance in the DRV IC output.
Those are the things that can cause opposite sidedband problems in
decreasing order
from top to bottom of likelihood. In the 3 board stack, the bus switch
is right on the
amp. It can get into problems and blow. WN8R got a 3 board stack and
upgraded
to RFE and he found exactly what you found and the bus switch (U2) was
bad with
an internal short.
I see no image problem here at all in the software and can't here any
serious problem
on my K2 sitting next to my SDR-1000. There is an image but it is
measureably
hugely weaker than the primary. At least 35 dB weaker, and probably
more like
40 dB.
Bob
Klaus Lohmann wrote:
Hi all,
hard to evaluate the compander (thanks for the new approach!) because sideband suppression does'nt match the needs. Signal is readable in both sidebands. One can observe the mismatch by looking at the spectrum during transmit. Changing limits of the TX-filter does not have sufficient effects.
73 - Klaus, DK7XL
3-stack SDR, Delta44 without preamp.
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