Apache Labs Community Forum

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 . 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:
Juha
NI2M

The RX passband and TX freq appear to be exactly 6KHz apart. What am I missing?

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".

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.....

What happens if CTUN is activated?

Hey Chris!

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

73,
Juha
NI2M

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

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.

Thanks Chris!

Hope to catch you on CW some time.

73,
Juha

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

https://github.com/ramdor/Thetis-2.9.0/issues/79

Thank you Chris!