SDRs (Software Defined Radio) decimate / downsample. Look at SDR
documentation.
Google turns up: https://dspguru.com/dsp/faqs/multirate/decimation/
Robert
On 02/21/2020 03:09 PM, Gary E. Miller via time-nuts wrote:
Yo Magnus!
On Fri, 21 Feb 2020 20:33:46 +0100
Magnus Danielson via
Hi
Ok, but thats “high pass in the RF section”. You really do not have an audio
high pass
filter the way you would in a more typical DMTD.
If it’s any comfort, I’m sitting here looking at a very different box. It also
has “wobbles”
as you get into parts in 10^-16. That might change a bit if
Dear Bob,
The capacitors are 47n NP0/C0G types (Kemet C0805C473K3GAC7800), picked for
low tempco (and low DF and other non-ideal behavior). I've not spotted any
hysteresis artefacts in these in previous designs, but I haven't measured
their performance in this circuit.
Forgot to mention in the
Hi
What does the temperature coefficient of your “hardware HPF” filter caps look
like?
Are they a type that has significant hysteresis?
Bob
> On Feb 23, 2020, at 3:05 PM, Jan-Derk Bakker via time-nuts
> wrote:
>
> Dear Attila,
>
> Thanks for the heads up.
>
> I am currently using a HPF
Dear Attila,
Thanks for the heads up.
I am currently using a HPF both in hardware (capacitive coupling into the
balun driving the ADC inputs) and in software before the ZCD. This should
counteract the first-order effects of this offset, although second-order
effects (converter nonlinearity et
Hi
Since most mixers also have DC offset issues, it is pretty common to high pass
filter
the signal before you try to hit a limiter. Yes, this can bring in other
issues, but the
net result is commonly a “win”.
Bob
> On Feb 23, 2020, at 2:10 PM, Attila Kinali via time-nuts
> wrote:
>
>