Settings: Meanings.

[SarahC_]

1.1 Volume : Speaker volume
1.2 Mode : Transmit mode, FM, AM, USB, LSB, CW
1.3 Filter BW : 500 Filter bandwidth - (what's this do?>>)
1.4 Band : 20m, 30m, 40, 60, 80m Frequency used, as wavelength
1.5 Tune Rate : Default change when rotating knob. Pressing button /10 frequency change. (little dot by digit)
1.6 Variable frequency oscillator Mode :. A or B. (No idea what it does???)
1.7 Receiver Incremental Tuning : On/Off (Why off/on and not a value???)
1.8 Auto Gain Control : Makes quiet signals louder automatically.
1.9 Noise reduction : 0 to ....0!
:
1.12 S-meter : off, dBm, Strength
1.13 Standing Wave Reflection Meter : off, fwd-swr, fwd-ref, pwr-eff, pwr-vss (pwr-eff will show watts / efficiency)
:
2.4 Semi QSK : Hear reception between keying in CW mode.
2.5 Keyer speed : Change the speed in milliseconds.
2.6 Keyer mode : Iambic A, Iambic B, Straight (Iambic has 2 buttons, dot and dash)
2.7 Keyer swap : Off / on
:
3.1 Voice Operated Transmit (VOX) : On, off
3.2 Noise gate : 4 (0 to 255) (No idea???)
3.3 TX Drive: Transmit driver, 4 (No idea???)
3.4 TX Delay : Delay after pressing PTT before transmitting
:
4.1 CQ Interval : 5 (No idea??? Some sort of automated CW TX?)
4.2 CQ Msg 1 : CQ [Callsign] +
4.3 CW Msg 2 :
4.4 CW Msg 3 :
4.5 CW Msg 4 :
4.6 CW Msg 5 :
4.7 CW Msg 6 :
:
8.2 PA Bias max : 128 (No idea???)
8.3 Ref freq : 27,000,000 (No idea???)
:
8.6 R Shunt: 18 (No idea???)
8.7 LPF Config : Lo, High, Classic (Low pass filter, no idea what 3 options do???)
:
9.7 F/W: 2.00x (or 1.00x, 3.00x etc...) (No idea???)

[SarahC_]

Any additions to help with the unknown ones - more than welcome!

[KE0QQQ]

The search function will give you what you are looking for

I searched one as an example >> R Shunt

I found the answer on the 3rd answer >> https://forum.dl2man.de/search.php?keyw ... mit=Search

[SarahC_]

Thanks KE0QQQ!

That's a great help. Wonderful. I can go through them next weekend and add the one's missing. I see that one's for calculating the efficiency. =)

M7OSX

[VA3KTJ]

This is an excellent summary; however, it is unfortunate that the majority of the questions remain unaddressed or insufficiently explained.

I was looking for good explanations on each of those menu settings, but couldn't find one.
Is there any manual/reference for all the menu setting items?
Many people would think most of the menu items are self explanatory, but I have similar questions as SarahC_ has.
Thank you all.

[Miss_Sissy_KM4QLB]

8.3 Ref freq : 27,000,000 (No idea???)

This setting is how you adjust the (tr)uSDX so that the displayed/commanded frequency matches the actual frequency at which the (tr)uSDX transmits and receives. The default of 27.000000 MHz default frequency is in the ballpark of correct, but each (tr)uSDX has a reference clock that runs a bit faster, or slower, than that.

On mine, the proper setting is 26,997,700 (yours will almost certainly be different). When using the default setting of 27,000,000, the transmit/receive frequency of my (tr)uSDX was about 860 Hz low when set to 10 MHz. That matters a lot when you're working in a 3,000 Hz bandwidth on FT8.

The easiest way to calibrate the (tr)uSDX without test gear is to use the "Freq Cal" mode of WSJT-X. It has a dozen different reference frequencies which can be trusted to be exactly correct. Most in region 1 come from transmitters operated by the National Institutes of Standards and Techology. Try them out and find one that gives you a good signal at your location with your antenna. More information on the sources and how they can be used to calibrate your rig can be found through your friendly neighborhood search engine.

[VA3KTJ]

8.3 Ref freq : 27,000,000 (No idea???)

This setting is how you adjust the (tr)uSDX so that the displayed/commanded frequency matches the actual frequency at which the (tr)uSDX transmits and receives. The default of 27.000000 MHz default frequency is in the ballpark of correct, but each (tr)uSDX has a reference clock that runs a bit faster, or slower, than that.

On mine, the proper setting is 26,997,700 (yours will almost certainly be different). When using the default setting of 27,000,000, the transmit/receive frequency of my (tr)uSDX was about 860 Hz low when set to 10 MHz. That matters a lot when you're working in a 3,000 Hz bandwidth on FT8.

The easiest way to calibrate the (tr)uSDX without test gear is to use the "Freq Cal" mode of WSJT-X. It has a dozen different reference frequencies which can be trusted to be exactly correct. Most in region 1 come from transmitters operated by the National Institutes of Standards and Techology. Try them out and find one that gives you a good signal at your location with your antenna. More information on the sources and how they can be used to calibrate your rig can be found through your friendly neighborhood search engine.

This is really good tip for those who don't have any other reference RIG. TU, Miss_Sissy.

[KE0QQQ]

Hello

I have 2 radios that were on the high side of default for 8.3 Ref freq. One was under like described here

It is possible to listen to known good stations and twirl the knob till the duck sound is gone and find a middle ground in its setting. When its zeroed in you can hear others when they are slightly off.

Then FT8 calls are in the middle of the scope as well.

[Miss_Sissy_KM4QLB]

VA3KTJ wrote:

This is really good tip for those who don't have any other reference RIG.

Thanks! I'm sorry if I left the impression that WWV-based frequency calibration in WSJT-X was some sort of fallback or second-tier option. It's both easier and usually 'better' than using another ham rig as your frequency reference.

The WWV frequency accuracy is 1 x 10^-13, which means that the 10 MHz WWV carrier should be off by no more than 0.000001 Hz at the transmitter. You can safely assume that the frequency at your antenna will be 10 MHz ± 1.5 Hz (see article at link below re. Doppler shift). Unless your reference rig has a cesium atomic clock for an oscillator, you're probably better off using the NIST WWV carriers as your frequency references.

The ARRL's QST magazine had a 2023 article entitled Measuring the Frequency Accuracy and Stability of WWV and WWVH: An examination of just how accurate these frequency standard stations are. NIST made the article available at this link:

https://tsapps.nist.gov/publication/get ... _id=935451

[VA3KTJ]

Thanks again Miss Sissy for great detail about the WWV based frequency calibration. I will take a look at the link.