I have an older AA-230 Zoom and a 6ish month old Stick? Pro.?

I went to make up a 1/4 wave stub to notch out some interference and by accident? discovered that the two units disagree. The Stick? Pro says 97.991MHZ and the AA-230 says 96.409MHz. I set them both to check the length of the stub and the result was identical on both.

Another weird thing is that the AA-230 when set to TDR and a sweep is started, it says you can cancel the sweep by hitting the X (cancel) button. If I do this, the AA-230 locks up and I have to remove a battery so it resets and then re-install the battery and all other functions work fine.
The AA-230 passes ALL the self diagnostics and has been updated to the latest firmware.

This leaves me with the question, which one is reporting an incorrect stub length frequency and is there a problem with the AA-230 TDR mode locking up the unit when cancelled. If the TDR scan is allowed to complete, the unit behaves normally (The TDR scan with the AA-230? in much slower than the Stick Pro, but I'm assuming it's simply a faster processor in the Stick Pro).?

Does anyone have any advice?

Regards

Chris VE4FU

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Dear Chris,

The Stubtuner tool in RigExpert analyzers (without prior preparation) works well for the HF band.
In your case, we are talking about VHF. At such frequencies, literally everything matters to get a reliable result: the length of the open ends of the cable (for short), the method of connecting the cable to the antenna connector (only using a connector, no bare wires!), The force with which the connector was twisted.
If you need to get high accuracy for high frequencies, you must follow all the rules for working with an RF signal.
Well, of course, it is necessary to calibrate the analyzer using a high-quality OSL standard.
As for the AA-230 Zoom. What version of the analyzer firmware?

Best regards, Alex UT2UM

I have an older AA-230 Zoom and a 6ish month old Stick? Pro.?

I went to make up a 1/4 wave stub to notch out some interference and by accident? discovered that the two units disagree. The Stick? Pro says 97.991MHZ and the AA-230 says 96.409MHz. I set them both to check the length of the stub and the result was identical on both.

Another weird thing is that the AA-230 when set to TDR and a sweep is started, it says you can cancel the sweep by hitting the X (cancel) button. If I do this, the AA-230 locks up and I have to remove a battery so it resets and then re-install the battery and all other functions work fine.
The AA-230 passes ALL the self diagnostics and has been updated to the latest firmware.

This leaves me with the question, which one is reporting an incorrect stub length frequency and is there a problem with the AA-230 TDR mode locking up the unit when cancelled. If the TDR scan is allowed to complete, the unit behaves normally (The TDR scan with the AA-230? in much slower than the Stick Pro, but I'm assuming it's simply a faster processor in the Stick Pro).?

Does anyone have any advice?

Regards

Chris VE4FU

Alex,

As for the AA-230 Zoom. What version of the analyzer firmware?

Version 1.119

I redid the tests, the AA-230 consistently reads 1.5MHz+ higher than the Stick Pro. Loosening and tightening the connector does have an impact, but it's only around 100KHz. Same connector used on both meters and as I am using only the N connector? on both rigexpert units, I saw no reason to re-calibrate them as they should be factory calibrated to the connector.?

Regards

Chris VE4FU

When I go to that link, I don't see any firmware. I did run the updater tool a few weeks ago and it updated to 1.119. I'll check again later today.

I must apologise to Alex as when I did do a calibration on both units, the stub is now the same frequency on? both units.

I'm left with the issue of the firmware locking up when cancelling a TDR sweep, but that might change if there is a new firmware available.

The only other item is the SWRtoAIR feature... There is no modulation, just the carrier with at least THIS firmware. Hopefully the newer one works correctly.?

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I have been advised that for general use you do not have to calibrate a RigExpert as the factory calibration is good and it is an “average” result you will get. ?For specific frequencies and accuracy recalibrate at the frequency of question. That was the explanation I was given as to why I didn’t have to REcalibrate my RigExpert tools like I do for my NanoVNA. I hope that helps someone.

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Sorry to hear Alex, that sounds terrible!

I updated to 1.120 last night. The crash when killing a sweep in TDR mode remains, it did work correctly once, but after that it simply locks up and I have to remove a battery to get it to shut down and allow me to use the device again.
SWRtoAIR also continues to be non-modulated.... it transmits, but there is no audio... just the click-hiss of a carrier breaking the squelch on my HT.

Considering calibrating in preparation for tuning a stub seems to solve that problem, I'll call it good. It works fine without calibration for typical SWR use and the two analysers, while not identical, are very close to each other and close enough for ham radio use.

Honestly,? I just wish I could get SWRtoAIR to work properly. Simply allowing the TDR mode sweep to complete allows everything else to work normally after that. I just hope I don't have a hardware issue in the AA-230 Zoom as it is out of warranty.

Regards

Chris VE4FU