Frequncy Calibration / random change

N2QQF
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Frequncy Calibration / random change

Postby N2QQF » Tue May 03, 2022 2:00 pm

I was hoping someone could provide some insight, not sure what is happening but for two days now I have had to randomly re-calibrate the radio. I turned the radio on and nothing has changed on my end but I am having moments that everyone seems off and then I QSY between bands and come back occasionally the frequency is slightly off on both transmit and receive. Its not RIT / XIT but clearly something that gets corrected when I re-calibrate. The radio isn't hot either, so I am having difficulty figuring out what it might be.

As mentioned, a quick calibration and its fine but I am wondering what could be happening and if anyone else has noticed this or is it an isolated issue. BTW... I am running version x64 Protocol 2 Ver. 21K9b

Any feedback is greatly appreciated.
dynamicfusion
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Re: Frequncy Calibration / random change

Postby dynamicfusion » Tue May 03, 2022 6:20 pm

Did you happen to do what I did and upgrade recently? I noticed that always resets the calibration back to 1.0.... Mine is set at 0.99999883 and always reverts when upgrading.
K1LSB
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Re: Frequncy Calibration / random change

Postby K1LSB » Tue May 03, 2022 6:39 pm

What exactly did you "upgrade"? Thetis? Windows?

I've never had the Calibration value reset when I upgrade Thetis or Windows.

Mark
N2QQF
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Re: Frequncy Calibration / random change

Postby N2QQF » Tue May 03, 2022 8:24 pm

dynamicfusion wrote:Did you happen to do what I did and upgrade recently? I noticed that always resets the calibration back to 1.0.... Mine is set at 0.99999883 and always reverts when upgrading.


I have not upgraded any software or anything for that matter. Everything has been operating without issue for quite some time now since it was put on the air. Honestly, it started when I gently slid the radio out to plug the speaker cable into the rear jack and when I placed the radio back in its position, it was off frequency. This all happened yesterday and that was the very first time anything of the sort happened. Then it happened again this morning. There have not been any temperature changes, radio isn't moved often. I could say OK, maybe something off happened, but twice within a 24hr period seems extremely odd.
rdwing
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Re: Frequncy Calibration / random change

Postby rdwing » Thu Jul 28, 2022 11:28 pm

I noticed this behavior on my recently manufactured 7000 DLE Mk3. My normal calibration offset is 1.00000278. Randomly, something will change and I'll suddenly be off frequency, requiring a new offset of 1.00001478 or thereabouts.

The strange thing is, if I quickly power cycle the radio the old normal calibration offset becomes correct again...it's like something is losing sync.

I'm running 2.9.0.6 Thetis with the only available firmware for a Mk3.
rdwing
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Re: Frequncy Calibration / random change

Postby rdwing » Wed Aug 17, 2022 10:37 pm

I am still seriously struggling with this issue. I have now found a way to reproduce it.
The rig is calibrated with a 1.00000313 correction factor. This is generally stable and right on the money, within 1hz.

If I switch to 10m, or 6m, make a transmission of about 15 seconds, when I unkey the radio will suddenly be off frequency. It doesn't matter if its CW via TUN, SSB, anything. To get back on frequency, I'd have to use a 1.00001504 correction factor (notice this is quite a big difference).

The radio does not drift back to a lower calibration point. If I quickly power cycle the radio, the original correction will suddenly be correct. This occurs both into an antenna and into a dummy load.

If I power cycle the radio, the original correction will be correct.

Any ideas?

This behavior has occurred on both P1 and P2 for the Mk3 rigs.
rdwing
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Re: Frequncy Calibration / random change

Postby rdwing » Tue Aug 30, 2022 10:24 pm

Well this continues to be a problem. I guess nobody else has been able to test nor replicate the behavior. Perhaps the unit is faulty.
dynamicfusion
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Re: Frequncy Calibration / random change

Postby dynamicfusion » Tue Aug 30, 2022 11:31 pm

Curious, if you left the calibration at 1.0, does it persist in changing? If so, by how much?
Tom AA4VV
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Re: Frequncy Calibration / random change

Postby Tom AA4VV » Wed Aug 31, 2022 3:40 pm

You can't calibrate the radio if it is in CW mode. The calibration will be off by the same frequency as the CW pitch.

Just something to check.
rdwing
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Re: Frequncy Calibration / random change

Postby rdwing » Tue Nov 01, 2022 8:50 pm

I'd just like to bump this again. I think I understand that the frequency standard in the radio is a VCXO, perhaps there is some problem with the voltage regulation.
Even with the radio left at 1.0000000 cal correction, the issue occurs above 20m when transmitting for more than 15 seconds, even into dummy loads.

I took a video to try and illustrate the problem. It shows WWV coming in strongly and on frequency, going to 6m and transmitting a 30w carrier for some seconds, and going back to WWV which is now off frequency by 240 hz.

https://youtu.be/To67r_nTCOM
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w-u-2-o
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Re: Frequncy Calibration / random change

Postby w-u-2-o » Tue Nov 01, 2022 9:36 pm

The 10MHz reference oscillator on all openHPSDR boards, from the Hermes to the Orion, is a TCXO (temperature controlled crystal oscillator). From the Orion card on this part has been the Conner Winfield M100F.

http://www.conwin.com/datasheets/tx/tx382.pdf

Normally the stability is quite good, it is ±100ppb from 0 to 70C.

When you power cycle the ANAN, it resets the 10MHz TCXO, the Crystek CVHD-950 122.8MHz sample clock oscillator (a VCXO which is controlled by a low pass filtered PWM signal from the FPGA), and the FPGA itself. If it's a hardware problem it could be in any one of those hardware components.

It could be a firmware problem but that seems unlikely. If it was a firmware problem then there would be a lot more people complaining about this issue. Plus you tried both P1 and P2 firmware.

You probably have no way to try this, but if you had an external 10MHz reference then you could rule in or out the M100F TCXO.

Given that it is a new hardware it might be best to seek out factory service for it.
rdwing
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Re: Frequncy Calibration / random change

Postby rdwing » Wed Nov 02, 2022 11:50 pm

administrator wrote:Here are some points I just shared with a customer:

1. More that 50% of the new FPGA is free and available for future additions, the device was chosen keeping in mind the future requirements
2. There is absolutely no change in the bootloader/Firmware Verilog code, only the device has been redefined and compiled in Quartus, which also means that firmware porting to the new device is relatively easy given the expertise of our developers.
3. We are and will continue working with the developers to ensure full compatibility with all HPSDR protocols
4. The Orion MKII boards has several improvements:
a. Improved power rails and LDOs which especially help with the extra power requirements for protocol 2 and future needs
b. Support for the New KSZ9031RN PHY makes the board future proof since the current PHY KSN9021RL used in the Orion MKII is EOL
c. Inclusion of an Ultra low noise LDO for the master clock will considerably improve Rx/Tx phase noise

You should be able to use the updated radio with Thetis, PowerSDR, LinHPSDR, PiHPSDR as before without any problems, so I believe your fears are completely unfounded.

If anything the new board offers a number of improvements over the Orion MKII and replaces several EOL parts with active parts.

Hope this helps,

Regards,

Tony,
Apache Labs Support


Hi Scott. Thanks for the information.
This is from viewtopic.php?f=27&t=4266&p=21047#p21052, when Apache Labs changed parts and shipped radios before informing their customers of the change. Do the parts you specified include these changes? I would think 4 A and C could be part of the problem here. Just trying to figure out exactly what it is. Do we actually know what specific changes were made for power rails/LDO's and LDO on the master clock? Perhaps could there be a problem with them? I don't think there are that many Mk3's out there just yet. I have spoken with just a couple people who had Mk3's with the issue and more without.


And finally just as a note, the Crystek CVHD-950 must be either a 12.288 MHz or 12.8 MHz oscillator, because it doesn't come in 122.8 MHz flavors. Also would be interested if you know what the 10 Mhz reference is.
Last edited by rdwing on Thu Nov 03, 2022 7:39 am, edited 1 time in total.
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w-u-2-o
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Re: Frequncy Calibration / random change

Postby w-u-2-o » Thu Nov 03, 2022 1:30 am

rdwing wrote:Do the parts you specified include these changes?

Those parts are the same across all boards from the Orion through the Orion MKIII.

I would think 4 A and C could be part of the problem here. Just trying to figure out exactly what it is. Do we actually know what specific changes were made for power rails/LDO's and LDO on the master clock?

If the schematics I have are correct we do know precisely what the changes are. The only change is the addition of an LT1761ES5-3.3 LDO regulator on the input to the 122.88MHz VCXO instead of feeding it from the 3.3V rail directly.

Perhaps could there be a problem with them?


Perhaps, but I can't think of what they might be.

I had to edit this post. It had previously focused on the output capacitance provided for the LDO regulator, and of course there is plenty, with C600, 167 and 168 in parallel on the output, as shown in the schematic snippet below.

Capture.JPG
Capture.JPG (58.66 KiB) Viewed 1916 times


And finally just as a note, the Crystek CVHD-950 must be either a 12.288 MHz or 12.8 MHz oscillator, because it doesn't come in 122.8 MHz flavors.

My apologies. I should have written 122.88MHz. That's exactly what it is. It is not 12.288 or 12.8.

Also would be interested if you know what the 10 Mhz reference is.

I already told you. Go back and re-read.

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