[hpsdr] 31db attenuator
K4KV
k4kv at k4kv.com
Tue Apr 4 04:42:49 PDT 2017
Hello,
I have been struggling for some time with the rx attenuator on my
hand-built Hermes boards. I felt like the
mini-circuit part never worked correctly. I just got in some brand new
chips and replaced the chip. No
difference!
I got both the old and the new data sheets. The new part is the
DAT-31R4A SP+
It is 6-bit and in 0.5db steps. The original part is 5-bit and in 1 db
steps.
So, it is my contention, that this could never work correctly. The only
part that is available is the new part, the
6-bit part.
The reason I verified this is that I got an older Hermes board that was
factory built and repaired it. It has the old
mini-circuits part, and works as it should.
Can someone make me a version of Hermes code, or can we make a version
that supports both the 5-bit and 6-bit
parts? I did not get that deep into the programming of the chip, but it
may be as simple as always sending a 6
bit code, and moving the old 5-bit data to the end.
73
Glen K4KV
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