开云体育

Hans,

?

I appropriate the reply but wasn't expecting you to post back as I know you're away on your holiday.

?

Thank you though. :-)

?

Cheers,

?

Mel. M0KMD.

From my experience, it seems random. I got it to complete to about 2000 on one occasion after tinkering with the band settings for 20m. Without changing anything else, the next run only got it about 600 and was not able to get another complete run.

You can see my plots just a few posts below. /g/QRPLabs/message/142310

?

@Hans, any theories as to why this is happening?

?

Cheers.

?

Mel. M0KMD.

?

On Thu, Apr 3, 2025 at 02:02 AM, Mehmet Dinch wrote:

does it complete on consecutive runs for the same band or is just, seemingly, random?

I usually didn't try again after I got it to work.? So I don't really know.? In fact, I have no idea why changing the band settings would help it to work - I don't think it has a direct relationship - probably something more subtle.? But without changing band settings, it would repeat the same bad run each time.

Hi Stan,

?

Out of curiosity, does it complete on consecutive runs for the same band or is just, seemingly, random?

?

After some couple of hours of messing around with band settings, I did get it do a complete run on 20m. Without changing anything else, I ran it again to be consistent, the calibration quit at about 600 with another, seemingly, random plot!

I couldn't get it to do a complete run again after that with the same band settings.

?

Mel. M0KMD.

Oops.? My reply and comments were intended for Mehmet.?

I have some bands that have crazy-looking graphs like the ones he posted - even after I got them to complete all the way across.? But after they completed all the way across, the gross distortion was gone.

?

Your note, Yun, about the 80m plot not finishing all the way across, but still you get good audio (after turning off the swap) - that shows that my theory is not the complete story, even though it has worked for me and a few others...

Hi Mehmet,

?

Everything looks for me. I have no ideas now. I don't have a QMX+, instead, a QMX HB version and a QMX LB version. And 80m is the only band I had trouble with.

--

73, de BD8BTE
op: Lun Yang

Hi Lun,

?

The phase error plot doesnt complete for most of the bands, not just 20m. All of the plots just look random zigzags and never the same on consecutive runs. Some are just a straight lines going across the top of the screen and these seem to complete ..

?

This is what I get on 20m..

?

?

?

No Tx

?

During Tx

?

Mel, M0KMD

?

?

?

?

Stan,

?

My supply voltage is 12V, and I always use a 12V supply. The plot on 80m never comes to 2000 on the x axis, no matter how I play with the band configuration. After I disabled "20/80 BPF TXswap", the plot is still not complete as you saw, but the audio is good now.

--

73, de BD8BTE
op: Lun Yang

Lun, the first plot you showed here, with values out to 2000 on the x-axis may work fine, and give you good audio, even though the plot is not smooth.?

?

I presume your supply voltage was around 9V? (corresponds to about 2000 on the x axis).

?

The reason is, as I have verified by experiment,? that all of the values across the plot need to be initialized to avoid distortion in the audio, up through your full supply voltage range.? When the calibration does not complete,? leaving part of the plot unpopulated, audio distortion results.

Hi Mehmet,

?

I think the calibration procedure relies on both TX and RX. Is your RF/LPF scans look good on 20m?

?

And transmitter voltage should be near 0V when not transmitting.

--

73, de BD8BTE
op: Lun Yang

Leaving the 20/80 BPF TXswap disabled,? I messed around with the band edges and center frequencies for 20m and ended up with this. It doesnt resemble any of the examples I've seen:

?

Is this good, bad?

?

I also, I found that leaving everything as is and rerunning the same calibration, I get a totally different plot!

?

?

?

Lun, are you getting the same plots consistently on each consecutive run on the same band?

?

I cant make any sense of this at all...

?

Mel. M0KMD.

Hi Lun,

?

Thanks for the tip.

Sadly, it didn't work for me.

?

?

?

?

Mel, M0KMD.

?

?

Solved! I did what Hans says here: /g/QRPLabs/message/141354

?

?

This is 80m calibration looks like now. And I'm sounding great on 80m with PD on!

?

--

73, de BD8BTE
op: Lun Yang

Yes, we think we have discovered that if the Phase Error calibration does not complete (yours only went to about 600 on the x-axis), that the audio is corrupted, presumably because all of the rest of the values in the table are not initialized.

?

If you can repeat that calibration and make it finish, your audio will sound good again with PD turned on.

Some of us were able to make the calibration complete by adjusting the center frequency or band edge frequency in the Band Configuration screen.? We don't know why this makes it complete, but playing with the band frequency values often works.???

You should make note of the original values, and restore them after you get the Phase Error calibration plot to complete.

?

Hans has this on his list to look at when he returns from vacation.?

?

Good luck, Stan

I have very bad audio distortion on 80m band with PD tuned on. With PD turned off, I'm?

satisfied with the audio quality.

?

I think there's something wrong with the calibration. Here's my calibration result on 80m:

?

--

73, de BD8BTE
op: Lun Yang

Gary,

?

I'm not convinced that it is simply random. I was able to return the settings to default, or another intermediate experimental setting and repeat the calibration, getting consistent curve results for each setting before returning to my eventual best result, which Mel referred to.?

?

Running calibration of a band over and over again with the same settings simply repeated the same curve. I tried!!

?

Ellis?

GM4GZW

Adjusting the band edges makes no difference as the test frequencies are fixed. ?It is most likely that running the calibration over and over as you change band edges it might just work, but you wouldn’t be able to run it again working. It is just a random thing.

Gary

W9TD

Hi Hans,

?

I spent a couple hours adjusting the 20m band edges and center frequencies. I even tried the example given by Ellis (/g/QRPLabs/message/141909) and used that as a reference point. It always goes just beyond the 500 mark on the x axis and no more.

?

?

Mel. M0KMD

Try turning on the EQ then set the EQ to +20. Listen on another receiver for a change. My QMX would start to get raspy at a setting below +14. I set mine at +20 (max) and it sounded pretty good. Then I set my mic gain to 63 and compression to 5. It definitely made a huge difference in quality on mine. It was distorted and virtually no power output. I was able to make a contact on it to Kentucky after I changed those settings.

?

Don..N6NLX