Hi Charles.

The answer to that is looking like yes.

I say looking like because of the following.

- The last Beta release allows for scaleing the modem between
1000-3000 Baud.
- For some reason it will only talk to MixW on speeds 2200-3000. (No
Lower). But I think I know why, and hopefuly Kantronics will be able
to fix this.

I am starting to learn a lot about running more complex modes on HF.

It seems HF rig's generally suffer from a lot of problems when it
comes to running these more advanced digital modes.

- RF feedback / distortion is high on the list. RF gets back into the
audio stream very easily and distorts the injected audio. Even with
isolation transformers the ALC needs to be kept relativly low.

- All isolation transformers are not created equal! LOL. The audio
band pass characteristics vary greatly. The RX transformer I currently
use for example is slicing off 50% of the lower end of the audio
spectrum at 2300, 2400, 3000 speed settings.

- Once again with RF distortion of the audio. Isolation of the
antenna's feed line to the antenna can also help. As specially with
vertical's.

My next job is to find a reasonable source of isolation transformers
that have a better audio band pass spec and build a new isolation
interface.

I'd also be interested to hear more about modes like DRM etc and how
they have handled these sort of issues? Or wether the design of DRM
gets around these issues some how?

.-.-.

--- In Q15X25@yahoogroups.com, "Charles Brabham" <n5pvl@...> wrote:
>
> Ken, can you adjust the parameters for a lower baud rate and have the
> modem scale down automatically, as previos Q15x25 implementations do?
>
> The reason I ask is that on the 17 meter Q15x25 ARRL SkipNet last year,
> we were operating with 14 PSK streams at 2300 baud because the narrower
> signal worked out a lot better with most HF rig's available passband.
>
> 73,
> Charles Brabham, N5PVL
>