Have you read this??
https://www.qrp-labs.com/ultimate3/u3info/u3pa.html
--
Joe Leikhim
Leikhim and Associates
Communications Consultants
Oviedo, Florida
jleik...@leikhim.com
407-982-0446
WWW.LEIKHIM.COM
___
time-nuts mailing list --
Harmonics from a Si5351A is not a problem. As pointed out a LPF will do what it
takes to get the fundamental frequency "extracted". The Si5351A is designed to
clock/feed other digital circuits so that shouldn't be a problem in this
particular case either.
In the digital clock domain spurs are,
ecise time and frequency measurement"
>
> Subject: [time-nuts] Si5351A harmonics question
>
>
>
> 05/06/2019 16:24
>
> I am using a small transmitter called a U3S by QRP Labs as an exciter
> for a high power Class D amp. I take the output at circa 951kHz direct
> fro
Hi
Not quite sure what this has to do with time and frequency but ok ……
A spectrum analyzer has a “zero frequency” response. You can see this when you
do not have any input. It is clearly present on both of your plots. I suspect
you are
confusing it with an actual signal.
Analyzers are
That's what a square wave is ! A LPF will work on anything. I'm not sure why
you are using a class D amplifier though ?
Dave G4IUG
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to
Chris,
In general I'd say that the rather high level sidebands on your
signal are not reasonable at all, but I think I see what's *really*
wrong: your SA settings. It looks to me like the tall signal
is the DC spur, (a.k.a. "start spur") of you analyzer, and
the signal very near center screen is
05/06/2019 16:24
I am using a small transmitter called a U3S by QRP Labs as an exciter
for a high power Class D amp. I take the output at circa 951kHz direct
from CLK0 (it has no output stage built, I go direct from CLK0 on the
Si5351A and input it to a level converter based on a
