Owon DGE 2070 Frequency Stability Question

[MacMan72]

I have the afore mentioned AWG and I have been struggling with the frequency stability of this unit. After letting it warm up for maximum stability, when one of the channels is on, the frequency steadily climbs at about 0.02Hz/sec and when both channels are on, the frequency drops by the same amount. I would be fine if the frequency oscillated about its set frequency by that amount but the constant increase or decrease makes the generator basically unusable. Could this be a problem with the generator or is it just a function of the lower quality of the unit? There is no way to input an external reference so I constantly have to fine tune the frequency to keep it close to on target.

[J-R]

What frequency are you generating and what are you using to measure it?

[MacMan72]

I was working on a frequency divider circuit to change a 10 MHz reference signal to 1MHz so I can feed that reference into a Leader FC that has a 1MHz oscillator. I was reading the frequency on a HP 53181a referenced by the 10 MHz gpsdo. For most uses, that drift is small enough that it probably doesn’t matter, but trying to look at 2 signals on an oscilloscope when one of the signals is constantly degrading in frequency can be quite annoying. I have a adjust the frequency to just above the target, and then I get a few seconds of time before the frequency degrades enough that the speed difference between the two signals is enough to make comparison impossible. It’s not a show stopper, its just something I noticed during the process that made me wonder why it’s constantly degrading instead of oscillating about the set frequency. Seems like a flaw as opposed to a performance limitation to me.

[J-R]

Owon claims a "Frequency Stability" of 30ppm, but I'm not sure exactly what they mean by that.

I think 0.02Hz @ 10MHz (or 1MHz?) could be expected for this class of product, although you said 0.02Hz/sec, so I'm not sure how to translate that over longer periods.  Are you saying that it just drifts forever until it's off by 1kHz or something?

[MacMan72]

Yes, I assume so though I didn’t leave it on that long, I did let it go for well over an hour and it was still steadily dropping. At that rate it would take quite a long time to significantly degrade the frequency so it’s not really a huge issue, it’s just the only oscillator I’ve come across that doesn’t seem to have any feedback loop to try to zero out the error. It makes me think it’s a bug or a defect so I thought I would see if anyone else has come across this phenomenon.

[J-R]

I did find these two videos that may give you an idea if your unit is malfunctioning: