Some strange maybe "glitches" Aurora

K2BLA

I was operating 6m and the PWR meter is 240W full scale which makes sense as the power on 6m is limited to 200W. Then I switched to 40m the PWR meter still had a 240W full scale. But when restarting the SDR the full scale was 600W as it should be.

Also, after powering up the Aurora and starting SmartSDR there is a frequency jump of maybe 50Hz or so. The panafall display jumps and it can be heard. This occurs after about 2 minutes from when the SDR starts. I think it does it on transmit too. If I transmit before the approximately 2 minute delay I can hear the xmtr glitch. I noticed this on FT8. On CW I don't think I could hear it. This happens only once during an operating session. But the next time I fire up the rig it will happen; every time.

David Decoons, wo2x

OK, the external power disconnect is the same as the rear switch. I think you are seeing when the GNSS locks and it transistions from TCXO to GNSS reference.

73 Dave wo2x

KD0RC

Try a factory reset (after you export your profiles). If that doesn't help, submit a help desk ticket.

K2BLA

Thanks Len,

I got my Aurora only 3 weeks ago and it has had this "oddity" from day one. Doing a factory reset will only take me back three weeks. It is something I can easily live with for now.

I have a suspicion that since the small frequency jump only happens after the SDR has been running for a few minutes that it is related to the GPS disciplined oscillator. Because my GPS antenna is not real close to a window, it takes a minute or two to lock on to enough satellites to get a good frequency lock.

Also, if I shut down the SDR and start it up again after a minute or two, I get no glitch. I think the GPS receiver uses the very recent data it accumulated and gets a very fast lock on.

I will do some more analysis and share my findings with the community.

73, Al, K2BLA

K2BLA

As promised, more info. I was on CW this afternoon. I did not run the DAX or CAT apps, just the SDR. As usual about 2 minutes after starting the SDR the CW station I was listening to the pitch shifted about 50Hz and after a fraction of a second reverted back to the original tone. The panafall display shows the shift.

KD0RC

Hi Al, look at the power button when you start the rig. Does the 50 Hz shift happen when the button goes from green to blue? If so, then your suspicion that the radio has not yet locked on to the GNSS signal is correct.

David Decoons, wo2x

@K2BLA are you turning off the rear switch to turn off the Aurora when not using it? The “glitch can be switching from the internal TCXO to GNSS after it warms up.

K2BLA

Len,

I don't start the SDR until the power button light stops blinking and goes steady blue.

David,

When not using the Aurora, I don't use the back panel power switch but turn off a power **** which also powers up my router, external audio amp, keyer etc. In other words, it's the same as pulling the plug. This is after I use the front panel power switch and wait until the all the front panel lights go out.

The next test I am going to do it disconnect the GNSS antenna which will prevent it from switching from TCXO to GNSS disciplined oscillator. I will post what I learn.

Thanks to both of you for your comments.

K2BLA

I guess this portal doesn't like S T R I P. **** was power S T R I P

K2BLA

I mischaracterized my power on sequence. I start the SDR after the blinking green light on the power switch becomes a steady green. The Aurora is located such that I can't easily see the power light from the operating position. This AM I watched the steady green light change to blue which I discovered occurs at the same time as the GNSS rectangle on the lower right-hand corner of the display changes from blinking to steady. At that time, I got the frequency shift. I have had the Aurora for less than 3 weeks and I am still on the learning curve and assumed the steady green was "good to go".

But I also heard the clicking of relays in the RF deck when the blue light appeared. I would assume that relays are only used for switching high power RF. I don't like the idea of hot switching relays, so my new power-on sequence is don't transmit until the GNSS is fully locked. I can live with that now since I know what is causing the frequency shift.

But my power meter full scale situation is still there. This AM on 6m I had a 600w full scale while yesterday I had a 240w full scale on 6m. Sometimes when I change bands from 6m to HF I get the 240w full scale which should be 600w. Sometimes it is 600w on HF. I can't figure out what sequence causes the wrong meter scale. The meter scale seems to be a total **** shoot. Once again this is not a big issue because I am not running over 200w at the moment as I have some antennas that I am concerned that can't handle 500w. I will investigate them in the near future.

K2BLA

Just as I expected. "total **** shoot" is "total C R A P shoot"