[time-nuts] Modern signal generators

[Russ Ramirez]

Don, you mention digital attenuators. What parts do you have experience
with? I am in the midst of a signal generator design for a club build
project. Looking at digital attenuator parts now, but many are spec'd in
the GHz range. Looking to get down to -140 dBm from +20, or as close to
this range as possible. TIA

Russ

On Wed, Dec 12, 2018 at 11:00 AM <time-nuts-request at lists.febo.com> wrote:

>
> Rick: I've spent some time with the dds blocks. We found them to
> generate lots of low level spurs, making lots of "birdies" when used as
> local oscillators in receivers.
> We had better results using:
> https://www.silabs.com/products/timing/oscillators.
>
> These may be used with GPSDO clocks for accuracy, and generate less
> noise. Cost is about the same; there are two or three sources for
> breakout units. The clock sources do have to be 25/27 MHz, those from
> Leo Bodnar, or use an OCXO.  Digital attenuators are also available; all
> this can be run from an Arduino with oled or other readouts, libraries
> abound. And for quick and fancy GUI, on a pc, use MakerPlot.
> Just $.02
> Don
>