Did a couple of hours test on WSPR 28MHz earlier
Got a few spots which considering the band conditions and
my Windom's reluctance to tune on 10 meters was a result..
The PA FET gets hot on this higher band though....much too hot..
Not bothered by this as my second kit will be boxed with the DDR feeding a different PA altogether and I will be loosing the FET stage.
Anyhoo, it got out...
Screen grab here...
Philip G4JVF
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--- In QRPLabs@..., g3zjo <g3zjo@...> wrote:
Hi Hans
I tried various setting of the calibration, clutching at straws again,
Andy FTDbhas negative values ie. 124,999,xxx mine is 125,000,555 there
was no improvement in the narrow 3 Unit WSPR outputted.
I have tried extra decoupling of the DC supply at the DDS pins, no
difference.
I have eliminated any possibility of the Output stage feeding back to
the generator circuit by removing the LPF and the supply to the output
devices. I am now just using the DDS Module output.
Measurements of the output 'Square wave' which is actually sine I think
the module is rated for square wave use only to 1MHz from memory.
TX'ing WSPR :-
18.126100MHz - 7.0V pp, 19.126100MHz - 6.5V pp, 20.126100, 21.126100MHz
- 6.0V pp, 22.126100MHz - 22.126100MHz
By the time it get to 28MHz it is around 4.0Vpp but I think this is
irrelevant, what is happening to the signal generation process is more
relevant.
I stopped the measurement here because the fold over point is between
21MHz and 22MHz.
At 21.126200MHz WSPR normal height and 4 Unit WSPR which decodes is
generated.
At 22.126100MHz the 'fold over has taken place' the 4th data Unit
frequency is absent, I don't think it is an overall compression of the
data shift.
Attached and destined for my Files Folder is a Capture which clearly
shows a normal transmission at 21MHz followed by a cramped one at 22MHz.
The Grab is straight from the screen in real time no cutting pasting
etc. has been done so the results are obvious.
Clearly something is happening at this point in the code, arithmetic
error or whatever.
Posted to the Group. Please how many Ultimate 2's are there that are OK
on 21, 24 or28MHz, there do seem to be some reports from users. Can
someone confirm the above 'fold over point'. We need more facts for
Hans to investigate the problem.
Andy FTD your requested Set Up Mode........Just press the Left button
whilst WSPR is being sent, it goes into Sig Gen Mode like at the end of
the 21MHz Trace in the Att..
73 Eddie G3ZJO
