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#clock #QMXplus #clock #QMXplus

 

The clock on my QMXplus seems to drift many minutes every day. When I do an operating session or a POTA activation I will need to remember to set the clock when I sit down and power it up. I set the time to UTC to make paper logging easier.

I have a new quality CR2032 battery in my QMXplus in case you wondered.
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i haven¡¯t yet measured the clock drift, but was surprised it was significant. I think a number of contacts I uploaded to LoTW had no QSL because my estimate of the correct time was wrong. (A day or two later I discovered the time was way off before I uploaded, and changed the times in my electronic log to my estimated corrected time)
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Or I could get the OLG3 GNSS module which I think will set the QMXplus time, but that requires another component and setup to my portable kit. I probably won¡¯t bother but keep thinking about other solutions.
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My Home QTH transceivers are spot on the correct UTC time.
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I can take a PC or IPad and do my logging on it. Another component to take.
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Q: Before I decide what to do, How much does your QMXplus clock drift?
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Not sure about QMX but on other radios the system clock controls clock timekeeping. ?
And you can correct the actual (vs printed) frequency in the menu. ? (by Trial and error or get a good start by tuning it on a calibrated receiver) ??
 

I was rather surprised to note that the non-GPS clock in my QMX+ drifts as much as a few minutes over 24 hours.
Very interested to learn if there is a fix other than installing the GPS module.
73- Dan N3DTF
 

Gents, give me time

I will make it so that the RTC uses the onboard 25 MHz TCXO (very accurate) when powered. And when switched off, uses the 32.768 kHz crystal but calibrates it according to its experience with the TCXO while powered up... At present it is not calibrated

73 Hans G0UPL



On Mon, Apr 28, 2025 at 2:56?PM Dan Finegan via <dantomfin=[email protected]> wrote:
I was rather surprised to note that the non-GPS clock in my QMX+ drifts as much as a few minutes over 24 hours.
Very interested to learn if there is a fix other than installing the GPS module.
73- Dan N3DTF
 

Could you calibrate both TXCO and Xtal against the GPS?
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We'll keep you busy with all our requests.
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Chris
 

Yes, that too Chris.

The TCXO and Xtal should calibrate against the GPS if available.?
If the GPS is not present, the Xtal should calibrate against the TCXO.?

73 Hans G0UPL



On Mon, Apr 28, 2025 at 3:27?PM Chris KB1NLW via <chrisrey1=[email protected]> wrote:
Could you calibrate both TXCO and Xtal against the GPS?
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We'll keep you busy with all our requests.
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Chris
 

Thanks Hans, you got it (time, pun intended).?
For now, I will set the time when I sit down for another Ham session.
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I love my QMX! It has sparked a renewed focus on CW operation. And I will keep testing and making improvements to its SSB function ( like a mic preamp).
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Coffee coming! Thank you!
 

I have a GPS in all of my 3 QMX+ rigs. Time is spot on all the time and for a $22 option is well worth it IMHO. I just want to see the seconds displayed and I am pretty sure this is on Hans's list.
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73
-Mike
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Hans, et all,
re: QMX+ rev3, 027 firmware. I have the GPs module fitted and is working fine. How do I run a CAL (NOT SSB firmware), to accurately set the TCXO frequency please? All my WSPR stations are coming up about 150Hz low. I see in the manual there is an option to manually change the TCXO frequency but you also say the GPS module ¡®should¡¯ set this, or have you not implemented this yet??
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Also my RF output on 160m is 4.8w (12v) system, great, but then drops off across the freq bands to 800mW on 10m and 6m (input I approx 600mA). Can you recommend removing turns from which toroids to boost the power also please?
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73 Ken G4APB
 

Hello Ken

The GPS is not yet set up to calibrate the TCXO frequency.

73 Hans G0UPL



On Tue, Apr 29, 2025 at 10:16?AM KEN G4APB via <lfoofui.nbz42=[email protected]> wrote:
Hans, et all,
re: QMX+ rev3, 027 firmware. I have the GPs module fitted and is working fine. How do I run a CAL (NOT SSB firmware), to accurately set the TCXO frequency please? All my WSPR stations are coming up about 150Hz low. I see in the manual there is an option to manually change the TCXO frequency but you also say the GPS module ¡®should¡¯ set this, or have you not implemented this yet??
?
Also my RF output on 160m is 4.8w (12v) system, great, but then drops off across the freq bands to 800mW on 10m and 6m (input I approx 600mA). Can you recommend removing turns from which toroids to boost the power also please?
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73 Ken G4APB

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