Display showing my CW signal way higher than it is.....

Post Reply
JJ4SDR
Posts: 546
Joined: Fri Jul 30, 2021 10:09 pm
Location: TEXAS, USA

Display showing my CW signal way higher than it is.....

Post by JJ4SDR »

Was working SPLIT on CW just now, trying to snag TN8K and when I key the TX, my TX frequency appears to be roughly DOUBLE the XIT frequency. In this case I was transmitting 6kHz up, but when I key the radio, the display seems to show my CW carrier at around 12kHz above. I know for a fact that I am transmitting only 6kHz higher (used another radio to verify).

UPDATE: I forgot to mention that I've never seen this before :roll: . Or, perhaps I just didn't pay attention (I tend to not think this either as I am pretty careful when working SPLIT), but it is disconcerting to say the least to observe the "discrepancy."

See screenshot below:
Split op TN8K.jpg
Split op TN8K.jpg (449.32 KiB) Viewed 6041 times
Juha
NI2M
PC: 8 Core i7-10700 CPU @ 2.90GHz, NVMe SK Hynix 512 GB SSD, 32GB RAM
Windows 10 Home, Version 22H2
Thetis v2.10.3.4 x64
Protocol 2 v2.2.2a
User avatar
w-u-2-o
Posts: 6024
Joined: Fri Mar 10, 2017 1:47 pm

Re: Display showing my CW signal way higher than it is.....

Post by w-u-2-o »

The RX passband and TX freq appear to be exactly 6KHz apart. What am I missing?
Capture.JPG
Capture.JPG (108.3 KiB) Viewed 6022 times
User avatar
W2PA
Posts: 178
Joined: Sun Apr 09, 2017 6:34 pm
Location: LaGrangeville, NY
Contact:

Re: Display showing my CW signal way higher than it is.....

Post by W2PA »

I can confirm this happens - but it's a bug in the panadapter scale (frequency) markings, not in frequency control. Evidently when you go into transmit, it adds the XIT offset to the frequency scale. You actually do end up transmitting where you intended, 6kHz up, but the display shows it incorrectly as 12.

To confirm this I used an external receiver to test your scenario. I used a 6kHz XIT setting. When in transmit the panadapter showed me as being up 12kHz but on the external receiver my signal was actually up 6 kHz.

So, apparently the transmitter is doing the right thing but the display is lying to you about the frequency.

I'm surprised I never noticed this before, but then, when I use XIT it's usually no more than a few 10s of Hz - when I go further I use SPLIT. I also don't really look at the panadapter scale when transmitting.

You should report this as a bug on Richie's github as an "Issue".
73,
Chris, W2PA
JJ4SDR
Posts: 546
Joined: Fri Jul 30, 2021 10:09 pm
Location: TEXAS, USA

Re: Display showing my CW signal way higher than it is.....

Post by JJ4SDR »

Here's the display with actual key press when using 6 k SPLIT. TN8K was actually on 14,025.00 when I worked him. The screen capture puts him 6 kHz higher than the 14,025.00 kHz (14,031.00 kHz) and "consequently" my TX frequency shows 6 kHz higher than 14,025.00 when I transmit, looking more like 14,037.00 for my TX frequency

Perhaps I should take a nap as I am seeing things. This can't be right..... :roll:
Key press on 6k SPLIT.jpg
Key press on 6k SPLIT.jpg (512.36 KiB) Viewed 6015 times
PC: 8 Core i7-10700 CPU @ 2.90GHz, NVMe SK Hynix 512 GB SSD, 32GB RAM
Windows 10 Home, Version 22H2
Thetis v2.10.3.4 x64
Protocol 2 v2.2.2a
User avatar
w-u-2-o
Posts: 6024
Joined: Fri Mar 10, 2017 1:47 pm

Re: Display showing my CW signal way higher than it is.....

Post by w-u-2-o »

What happens if CTUN is activated?
JJ4SDR
Posts: 546
Joined: Fri Jul 30, 2021 10:09 pm
Location: TEXAS, USA

Re: Display showing my CW signal way higher than it is.....

Post by JJ4SDR »

Hey Chris!

Thank you for sending this. I thought I was losing my marbles :lol:

73,
Juha
NI2M
PC: 8 Core i7-10700 CPU @ 2.90GHz, NVMe SK Hynix 512 GB SSD, 32GB RAM
Windows 10 Home, Version 22H2
Thetis v2.10.3.4 x64
Protocol 2 v2.2.2a
JJ4SDR
Posts: 546
Joined: Fri Jul 30, 2021 10:09 pm
Location: TEXAS, USA

Re: Display showing my CW signal way higher than it is.....

Post by JJ4SDR »

Scott,

I haven't tried it. Could do that tomorrow. What Chris was writing was confirmation that what I am observing is actually "legit" and that there seems to be a bug that needs to be reported.

Juha
PC: 8 Core i7-10700 CPU @ 2.90GHz, NVMe SK Hynix 512 GB SSD, 32GB RAM
Windows 10 Home, Version 22H2
Thetis v2.10.3.4 x64
Protocol 2 v2.2.2a
User avatar
W2PA
Posts: 178
Joined: Sun Apr 09, 2017 6:34 pm
Location: LaGrangeville, NY
Contact:

Re: Display showing my CW signal way higher than it is.....

Post by W2PA »

By the way, Juha, you can also confirm you are actually transmitting where intended by switching to QSK mode. In that mode MOX is never activated and it's just like seeing yourself on a separate receiver. No panadapter scale shift takes place.

The scale shifting with MOX happens whether CTUN is off or on - no diff.
73,
Chris, W2PA
JJ4SDR
Posts: 546
Joined: Fri Jul 30, 2021 10:09 pm
Location: TEXAS, USA

Re: Display showing my CW signal way higher than it is.....

Post by JJ4SDR »

Thanks Chris!

Hope to catch you on CW some time.

73,
Juha
PC: 8 Core i7-10700 CPU @ 2.90GHz, NVMe SK Hynix 512 GB SSD, 32GB RAM
Windows 10 Home, Version 22H2
Thetis v2.10.3.4 x64
Protocol 2 v2.2.2a
User avatar
W2PA
Posts: 178
Joined: Sun Apr 09, 2017 6:34 pm
Location: LaGrangeville, NY
Contact:

Re: Display showing my CW signal way higher than it is.....

Post by W2PA »

I posted this as a new bug on the git repository, issue #79.

https://github.com/ramdor/Thetis-2.9.0/issues/79
73,
Chris, W2PA
JJ4SDR
Posts: 546
Joined: Fri Jul 30, 2021 10:09 pm
Location: TEXAS, USA

Re: Display showing my CW signal way higher than it is.....

Post by JJ4SDR »

Thank you Chris! 8-)
PC: 8 Core i7-10700 CPU @ 2.90GHz, NVMe SK Hynix 512 GB SSD, 32GB RAM
Windows 10 Home, Version 22H2
Thetis v2.10.3.4 x64
Protocol 2 v2.2.2a
Post Reply

Return to “Thetis”