(tr)uSDX Forum

Is there any way to see the ALC level of the transmitter? I use that for digital modes when setting the audio output level going into the radio.

Thanks,
Herb

Hello OM,

no it has no ALC
Simply adjust it once best in FT8 with a power meter and keep it little bit lower as in CW ....
should normally work for everything.

73 de Chris

That would assume one would have a wattmeter for that low power setting.

I'll see what I can come up with. In theory it should be a "set once and forget" type adjustment.

Thanks!

Herb

I know it's not exactly the same as adjusting settings by viewing an ALC meter, but I transmitted on JS8Call from my TruSDX to my base station at home about 5 miles away, and viewed the output of my TruSDX on the waterfall of my base station through a RealVNC connection. Then, I adjusted the attenuation slider on JS8 until there was no more splatter/QRM. It took a setting of about -35 on 40m, and -36 on 80m. I thought surely I wouldn't be outputting anything with that much attenuation, but I was able to get some replies, and confirm on PSKReporter that other stations hundreds of miles way could still hear me.

In OH8STN's blog post on his TruSDX kit, he described a similar process of tuning his windows sound settings based on viewing his output from a distance. He didn't go into great detail about how he accomplished this, though.

I figured out another way to tune audio output. First, you need to know what your digital modes are supposed to sound like under normal conditions. Just listen around the lower bands and get a feel for what a normal JS8Call or winlink signal sounds like. Then, transmit in those modes with your trusdx while listening on another transceiver. You can actually hear when things sound overdriven and terrible, and attenuate by ear until it sounds normal. Too much attenuation, and it will become too quiet. This has worked great!

KG7YSX wrote: ↑28 Jan 2024, 04:03 I figured out another way to tune audio output. First, you need to know what your digital modes are supposed to sound like under normal conditions. Just listen around the lower bands and get a feel for what a normal JS8Call or winlink signal sounds like. Then, transmit in those modes with your trusdx while listening on another transceiver. You can actually hear when things sound overdriven and terrible, and attenuate by ear until it sounds normal. Too much attenuation, and it will become too quiet. This has worked great!

I have success with this method. I first set audio levels with a public Websdr. Eventually, I bought a 2nd truSDX and Digirig to use as a monitor. Very useful for level setting and testing before joining a net or starting to POTA in the field.

73 Constrainted

Constrainted wrote: ↑30 Jan 2024, 06:43

KG7YSX wrote: ↑28 Jan 2024, 04:03 I figured out another way to tune audio output. First, you need to know what your digital modes are supposed to sound like under normal conditions. Just listen around the lower bands and get a feel for what a normal JS8Call or winlink signal sounds like. Then, transmit in those modes with your trusdx while listening on another transceiver. You can actually hear when things sound overdriven and terrible, and attenuate by ear until it sounds normal. Too much attenuation, and it will become too quiet. This has worked great!

I have success with this method. I first set audio levels with a public Websdr. Eventually, I bought a 2nd truSDX and Digirig to use as a monitor. Very useful for level setting and testing before joining a net or starting to POTA in the field.

73 Constrainted

Awesome!!!

https://qrpguys.com/qrpguys-power-swr-dummy-load

This is a great cheap kit for measuring swr and power output. Also includes a dummyload that can be switched in and you can find 3d printed cases for them as well.

Latest beta fw has audio drive level indication

I dont think that drive level is available when running a digital mode using usb cat and audio