SDR-1000 on the air

[WA1GFZ]

How about saying allow 100 watts PEP output with variable carrier level
set by user. Then attack the negative peak limiter.  fc

[Ian VK3KRI]

The programmer is having problems getting past the > 100%modulation = splatter and distortion concept.

Perhaps someone could convey the concept in a more articulate manner?

-ap

Maybe some explanations with assymetric modulation waveforms that can cause <100% downward mod but > 100% upwards mod?  I'll be they are thinking in simple sine wave terms where you can't have different upward and downward modulation percentages.  There are example in old ARRL handbooks  (eg '63 handbook Ch 10 Amplitude Modulation,  5 th sub heading labeled appropriately,  "Unsymetrical Modulation" shows a pic with +300% - 100%)
                                                                               Ian VK3KRI

[Art]

Thanks gang. All good suggestions and helped get the idea across. The function is now on the development roadmap. Next . . . drive for shortcuts on the road . . .

Thanks again,
Art

[Art]

I received the updated BPF board with a 160M bandpass vs the lowpass that was previously utilized. The results are outstanding. 160M is usable during the day and I can listen to Rush on 580 even though 720 is much stronger and used to saturate the front end.
AM TX tests are in process. Initially, I am running a 13W carrier and about 80-90W PEP with the mic gain maxed out. Less mic gain = less PEP as you might expect. I will see if I can get some on the air reports and observe the waveforms tonight.

-ap

[WA1GFZ]

Cool,
I don't see how it improved  the broadcast band though???
Sounds like they want happy customers.

[Art]

The broadcast band was previously overloaded with 6 +15 to +50dB over 50uV signals. They are now coming in under the bandpass and are attenuated 40dB or so and not overloading the front end. I had one station (720) that was literally 50dB over and just swamping the front end. 'couldn't listen anywhere in the AM band without hearing them.

My report on AM TX appears to have been premature. I hooked up a receiver on a dummy load and hear the carrier fine but the modulation is unreadable. I do hear an SSB signal but AM is grossly distorted at best.  'will need the spectrum analyzer to see what the PEP meter is reading.

-ap

[WA1GFZ]

50 dB over 50 uV so that is 90 dB over .5 uV  I wonder if the problem is the first mixer or your sound card?
I suppose you could use a little attenuation as you go lower in frequency.