On 2025-03-31 06:30, jjpurdum via groups.io wrote:

That's one thing Hans does right: He doesn't release stuff until he's
convinced it's bullet-proof.

*** Yup. That being said, the QMX+ is back on the shelf, and I'm back
to playing with the T41. Despite being a kit, the QMX is essentially an
appliance - from my point of view. Because it's closed source. For me,
its entertainment value is limited.

Hans has promised some sort of built-in language interpreter, and I
might go back to it when that's a reality.

- Jerry, KF6VB

Jack, W8TEE
On Sunday, March 30, 2025 at 09:30:34 PM EDT, jerry-KF6VB
<jerry@...> wrote:
On 2025-03-30 15:50, Greg KF5N via groups.io wrote:

Did you get a chance to look at the spectrum?
That seems like a lot of power for BS170s!

*** It's a digital PA. In the schematic, the BS170's are fed
RF by LOGIC gates. I think it's what's called a "class E".
They don't even have heat sinks. They output 5W without
breaking a sweat.
The spectrum looks good on my FTDX10. I haven't hooked it up to
a spectrum analyzer yet.
- Jerry, KF6VB

--
73 Greg KF5N
Links:
------
[1] /g/SoftwareControlledHamRadio/message/33305
[2] /mt/111990371/243852
[3] /g/SoftwareControlledHamRadio/post
[4] /g/SoftwareControlledHamRadio/editsub/243852
[5]

/g/SoftwareControlledHamRadio/leave/10484476/243852/1943518115/xyzzy
--
Jack, W8TEE
Links:
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[1] /g/SoftwareControlledHamRadio/message/33311
[2] /mt/111990371/243852
[3] /g/SoftwareControlledHamRadio/post
[4] /g/SoftwareControlledHamRadio/editsub/243852
[5]
/g/SoftwareControlledHamRadio/leave/10484476/243852/1943518115/xyzzy

--
Jack, W8TEE

On 2025-03-30 18:17, Dave Mueller AA3EE via groups.io wrote:

It is. They become extremely sensitive to load mismatches. The group
is full of reports of them failing, especially when an external tuner
is looking for a match.

*** I guess that's why the radio has a built-in SWR bridge, and fairly
fussy protection software.

Since I'm operating it into my Tiny Linear, the radio is isolated from antenna
SWR. Nobody hears me at 5W, anyway :).

- Jerry, KF6VB

On 2025-03-30 15:50, Greg KF5N via groups.io wrote:

Did you get a chance to look at the spectrum?
That seems like a lot of power for BS170s!

*** It's a digital PA. In the schematic, the BS170's are fed
RF by LOGIC gates. I think it's what's called a "class E".

They don't even have heat sinks. They output 5W without
breaking a sweat.

The spectrum looks good on my FTDX10. I haven't hooked it up to
a spectrum analyzer yet.

- Jerry, KF6VB

--
73 Greg KF5N
Links:
------
[1] /g/SoftwareControlledHamRadio/message/33305
[2] /mt/111990371/243852
[3] /g/SoftwareControlledHamRadio/post
[4] /g/SoftwareControlledHamRadio/editsub/243852
[5]
/g/SoftwareControlledHamRadio/leave/10484476/243852/1943518115/xyzzy

开云体育

I was just browsing their website, and I noted that Hans has finally released beta SSB software for the QMX. Downloaded it, ran it...holy crap, it works!

SSB is created by doing magic with the IQ signals and simultaneously amplitude modulating the power feed to
the *digital* PA - which is four tiny BS170 MOSFETs in parallel-push-pull delivering nominal 5W.

The IQ calibration is done via the serial interface terminal menus. You tell it to start, it prompts you to connect a dummy load - and it just does the whole thing UNATTENDED. All bands. Takes a while, at least a half hour.

It supports CESSB, predistortion, compression, a transmit equalizer, and something called "Mic noise cancellation".
This is unique: Hans found that his CPU's ADCs were noisy. There were noise spikes every 500Hz. So what he does is
he monitors an unused ADC channel, and uses the noise in that to cancel the noise in the main ADC mike channel. Wow.

Unfortunately, the software is both closed source and encrypted.

I've interfaced it with my Tiny Linear project, and am seeing about 50W out.

- Jerry, KF6VB

开云体育

I sent out five of those new display driver boards about a week ago and only saw posted that Terrance got his working as was able to use a 3-foot long display cable without display-T41 errors/lockups. ?Anyone else built it yet? ?I know i didnt publish an assembly manual before i headed out of the country but the thing is pretty simple and i did send out a note re how to make it work on 5v or 3.3v. ?

开云体育

If no voltage on pin46 then the teensy socket or teensy itself is bad. ?