(tr)uSDX on 50MHz or 144MHz?

[ka1gt]

I'm very new to the uSDX, but I've run a number of searches to see if anyone has made modifications that allowed operation on 50MHz or 144MHz. So far I have not found anything.

The Si5351 should be good to 200MHz, so there should be no problem at 50 or 144. When using the TS-480 emulation for CAT control, the TS-480 should support 50MHz operation (but not 144MHz). I don't need high power, a few hundred mW (or even <100mW) would be enough, so I suspect the PA would probably be capable of that. I don't care about efficiency. It would obviously need a different filter on the output, but that should not be a big deal.

The SN74CBT3253DBR has a rated bandwidth of 200MHz, so again should be up to the task.

This would presumably need software modification in order to allow 50 or 144 MHz to be entered (manually or via CAT) and for the correct output relay with the appropriate filter to be selected when 50 or 144 MHz was entered. For example they could be in the 80m and 40m positions since I don't use those bands. I'm familiar with Arduino programming, but the sketch looks pretty complex. I suppose given enough time I might be able to figure out what to modify! I do see references in the code to 160m and 6m and there's a line in there covering Si5351 clock setting at frequencies over 140MHz (though the Application note referenced seem to apply to frequences over 150MHz)

I don't see any hardware limitations on the generation of 50 or 144MHz SSB, but I'm not that familiar with the exact circuit details. The only frequency sensitive components seem to be the output filters. Frequency stability of the Si5351 might be an issue at 144, but that can be dealt with by feeding in a stable external 27MHz (or preferentially 25MHz) signal in place of the onboard XO (TCXO?). I'm assuming the clock of the Si5351 can be manipulated at 50/144 Mhz in the same way it can at 28Mhz (I.e. SSB modulation is possible).

So before I look more deeply into this, has anyone tried it or does anyone know any online documentation that might help. Also, if I'm missing something important in terms of timing accuracy or circuit performance at the higher frequencies that would actually prevent this being done, I'd be grateful if someone could let me know I'd be wasting my time!

Thanks in advance, 73
Bob, KA1GT

[DL2MAN]

Please have a look at the forum rules first:
This is (tr)uSDX Forum, not uSDX.
(Tr)uSDX Hardware and Code is not open and any hard- and software modifications are not supported and in violation of the license.

73 Manuel DL2MAN

[ka1gt]

Sorry for the confusion. As I said I'm very new to this and have yet to figure out the differences between the (tr)uSDX which I now understated to be closed source hardware and software and uSDX which is open source hardware and software and appears at first sight (to a newcomer) to be very similar, but not, I gather, interchangeable.

It appears with (tr)uSDX, what you get is what you get - and that's a very good thing for those who want exactly what if offers. If I want 50 or 144MHz, it looks like (tr)uSDX is not a route to that (unless at some point that's offered as an option!).

If I can live with 28-30MHz it looks like (tr)uSDX is a very good way to go. If I need 50-54Mhz or 144-148MHz it's looks like I'm on my own with a uSDX project.

Sorry again for the confusion.

73, Bob, KA1GT