(tr)uSDX Forum

Forgive me if this has been posted in another thread, I looked but couldn't find one. Middle of last summer I purchased a (tr)usdx kit off Amazon. After assembly, I found my frequency to be off. I calibrated it according to DL2MAN's video, but when I adjust 40m, 20 goes out, and vice-versa. 40m is 750Hz off when 20 is centered, and 20 is 2kHz off when 40 is centered. I assumed I assembled it wrong, and purchased another pre-assembled off ebay(verified seller not the fake) and I'm having the same exact problem. I didn't have the time to figure out how far off each frequency is on this one, but when I adjust 40, 20 goes out and vice-versa again. Can anyone help me fix this? I do have a nanovna, if that helps.
Thanks!

What are you calibrating against? The best is if you can calibrate against WWV by zero beating. Once you do write down the frequency in case you reset you rig.

I'm calibrating against my icom 7300. Running my sdx into a dummy load, setting both radios to the same frequency and adjusting the reference until I get dead on.(I did not know what zero beating is, but I think that is what I did based on a google search) however, after doing so, the other bands are off. I would have to write down reference numbers for each band and adjust every time I change bands.

Please check your icom7300 against some time normal.
It is easy to be detuned by flase menu setting or false firmware update.
It has also a "Reference" Setting, that -when you mess with it- detunes your Frequency.

Other possibility: Do WSPR with (tr)uSDX and look at RBN for your exact frequency.
Then corect and try again etc.

We are using the same xtal for all Bands, and there´s only 2 things that can lead to something you describe:
1. Your reference is off
2. You´re listening on the wrong sideband on one of your Bands

73 Manuel; DL2MAN

DL2MAN wrote: ↑31 Jan 2023, 13:18 Please check your icom7300 against some time normal.
It is easy to be detuned by flase menu setting or false firmware update.
It has also a "Reference" Setting, that -when you mess with it- detunes your Frequency.

Other possibility: Do WSPR with (tr)uSDX and look at RBN for your exact frequency.
Then corect and try again etc.

We are using the same xtal for all Bands, and there´s only 2 things that can lead to something you describe:
1. Your reference is off
2. You´re listening on the wrong sideband on one of your Bands

73 Manuel; DL2MAN

Thanks so much! I'll look into these as soon as I can!