Search found 18 matches

by mikael
Tue Feb 14, 2017 6:20 am
Forum: Code Corner
Topic: Raspberry Pi problem?
Replies: 18
Views: 4464

Re: Raspberry Pi problem?

That looks like HDMI interference to me.
Each state lasts for a variable period of typically an hour or two.

Does this happen to correlate with your screen saver? ;-)
by mikael
Mon Jan 16, 2017 11:43 am
Forum: General
Topic: Frequency Sweeps? What? Who?
Replies: 13
Views: 4021

Re: Frequency Sweeps? What? Who?

NoelC wrote:[...] or they shoot signals with a lot of power up into the sky.

Why is that? HF propagation is magic, you know. You can bounce around the globe using milliwatts if the conditions are right.
by mikael
Wed Jan 11, 2017 5:36 pm
Forum: Code Corner
Topic: rfchanged etc. semantics
Replies: 2
Views: 1235

Re: rfchanged etc. semantics

xx Changed indicates that the new value is in effect for the data delivered by this call. Using syncUpdate, you can calculate the exact sample this occurred, elsewise you only know it occurred somewhere within numSamples. The driver aggregates four low level packets for each stream callback. The bi...
by mikael
Mon Jan 09, 2017 8:24 pm
Forum: SDRuno
Topic: Copying digital modes with SDRuno
Replies: 5
Views: 2696

Re: Copying digital modes with SDRuno

Once I found how to select the audio output device in SDRuno, there was no problems decoding WSPR using the same setup as yours. Using the volume controls, you can monitor the levels of the Virtual Audio Cable masking sure you've got signal there. Of course, you can monitor them in WSJT-X as well. M...
by mikael
Tue Jan 03, 2017 11:09 am
Forum: SDRuno
Topic: Decoding digital voice with hardware possible?
Replies: 3
Views: 1484

Re: Decoding digital voice with hardware possible?

Oh, one clarification; the speech codec is only the last step of decoding digital voice modes. This is not very likely the step that causes your problems, but the earlier steps of the fsk bit stream demodulation. The AMBE3000 only handles the speech decoding.
by mikael
Tue Jan 03, 2017 10:52 am
Forum: SDRuno
Topic: Decoding digital voice with hardware possible?
Replies: 3
Views: 1484

Re: Decoding digital voice with hardware possible?

DSD uses the authors mbelib as speech codec. You can of course replace it with a hardware decoder, but I don't believe this is your problem. Instead it's more likely the levels of the audio stream from SDRuno not agreeing with the DSD input filters. First check the error rates DSD presents. If none,...
by mikael
Mon Jan 02, 2017 11:33 am
Forum: Code Corner
Topic: SoapySDDRPlay not working
Replies: 16
Views: 5577

Re: SoapySDDRPlay not working

This is actually a small flaw in the SoapySDR API semantics more than anything else. The function to locate the SDR device is more or less implicitly assumed to locate available devices. Unfortunately this function is used both when listing the devices in the system as well as allocating them for us...
by mikael
Sun Jan 01, 2017 9:26 pm
Forum: SDRuno
Topic: Really basic question...
Replies: 3
Views: 1188

Re: Really basic question...

A VAC got better SNR than a physical one. ;-) Actually, messing around with the signal levels can be troublesome using line out/in masking sure you are using the linear range of the DAC/ADC. Much easier just eliminating that issue using a virtual cable instead. There's free such for Windos, and usin...
by mikael
Sun Jan 01, 2017 7:28 am
Forum: SDRuno
Topic: Really basic question...
Replies: 3
Views: 1188

Re: Really basic question...

Most often you'll not find one monolithic program doing everything you need. Instead you use one receiver software such as SDRuno and then feeding the audio output via a "virtual audio cable" (aka "VAC") to a decoder program, e.g. fldigi ( http://www.w1hkj.com/ ) for many digital...
by mikael
Sat Dec 31, 2016 10:41 am
Forum: Code Corner
Topic: SoapySDDRPlay not working
Replies: 16
Views: 5577

Re: SoapySDDRPlay not working

Yes, the GNU/Linux kernel module sdr_mir3101 does not per se interfere with the RSP1, but it will mark it as busy and if the new SopaySDRplay honors this flag, that was very likely your problem. The old (Cliffie's) didn't care.

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