Hello,
sorry it is too complex to debug in Windows.
Best regards, Edouard.
Hello Marty,
this is control #10 here: https://github.com/f4exb/sdrangel/blob/master/plugins/samplesink/limesdroutput/readme.md
Best regards, Edouard.
2 Likes
@F4EXB Edouard,
Thanks for the clarification - Iāll try some settings and see if I can improve things for voice and CW and report back.
Also, Iām finding that there are times when I cannot tune HF easily and the tuning sometimes will revert back to 430 MHz. Iāll get clarity on this and post what I find when I play around with it later.
Again, thanks for the clarification on the sampling rate for voice - more later when I have it.
73 de Marty, KN0CK
Hello Marty,
just a guess: if you accidentally press the check icon in the sampling devices control. That is #2 here: https://github.com/f4exb/sdrangel/tree/master/sdrbase#3-sampling-devices-control then it does a complete re-cycle and thus reverts frequency to the default 435 MHz. This check button is used to validate the choice of sampling device (control #1) so it removes the current device and brings in the new one. If the same device is used this has the same effect as a complete re-cycle. By the way this trick can be used to reset the logical device if things go really wrong.
Best regards, Edouard.
@F4EXB, Edouard,
I tried transmit this evening and played with several combinations of sampling at 5.000.000 and different decimations and Iām still not getting clear audio on voice transmit. I can get CW to work, but havenāt been successful in voice operations. Also, even with the right antenna selected, my receive is non-existent in HF (even with NCO turned on) but I can receive the FM band (88 to 108 MHz) fine - and this is a verified good on HF LimeSDR. Gain is set to 60+, Wideband antenna is selected and connected to my primary station antennaā¦nothingā¦seems deadā¦At one time I could receive HF fine on this setup on Win10. I always check the setup with SDRConsole V3.0 to see off the LimeSDR is playing fine and it doesā¦tunes HF in that app perfect with great gain. Also, Iām seeing an issue where the NCO tuning will not allow me tune in 1 MHz incrementsā¦it keeps flipping back and forth between 20.000 kHz and 1.844.674 kHzā¦cant tune the NCO in the 20.000 kHz range.
What is your opinion in this? Please let me know - TNX es 73
de Marty, KN0CK
Hello Marty,
I have to check HF operation because I have never tried it actually. I use a SDRplay on HF normally. In fact the frquency displayed at the right of the NCO button does the LO mixing maths for you. So if your LO is say 446.450 MHz and the smaller dial at 446.050 this means that the NCO is actually tuned to -0.4 MHz. In fact it displays your actual center frequency of reception. I have just tried this configuration to listen to PMR 446 MHz band (446.0 to 446.1 MHz) that is quite busy in Europe. This is the configuration that I have and that works perfectly. Note that I am using the āRx lowā input not the āwideā:
Best regards, Edouard.
@F4EXB - Edouard,
Is there anything you can do with the gain control? The LimeSDR has PIA, TIA and LNA gains that I think are affecting the way I receive in HF with the Lime. Does your gain control have control of these three gain blocks? Thanks for the info on NCO and I was aware that it would provide the mix component for the actual tuned frequency, but there are times when I canāt tune when the tuner flips to 1.844.674 kHz - - I try to tune any of the segments and it just flips over to 30.000 kHz and when I try to tune that is flips to 1.844.674 kHz, etc. The NCO tuning becomes meaningless.
My wideband port on my LimeSDR functions real well on HF when Iām using SDRConsole V3.0 - looks every bit as good as Lo and Hi that are also HF modified. But Iād like to know how does SDRAngel know what receiver its tuning since it has the capability to tune two receivers. If itās just another instance of R0 (meaning R1) then thatās fine - Iāll see if that works, too.
I would like to use SDRAngel for the purpose of tuning receive and useful transmit for HF because I think thereās promise to the overall app, but there are still some issues that Iām seeing and would love to see those fixed somehow.
Let me know your thoughts - TNX es 73,
de Marty, KN0CK
Hello Marty,
this is how are my settings to receive the 40m band and it works. May be not optimal. I like the SDRplay better for HF but my antenna is a simple long wire attached to a MFJ-1644 tuner so it is not ideal. I noticed that the tuning is not exactly the same as with the SDRplay so the input impedance might be different.
Manual gain control has been there since version 3.5.1
The weird display on the NCO and inability to tune it correctly (going either to 1.844.674 kHz and another value depending on the sample rate) is due to the fact that half the ADC sample rate exceeds the LO frequency therefore the theoretical lower limit of the tuning range with the NCO gets below zero. I believe this is not handled properly when calculating the limits however you should not need such a combination. So with a LO at 30 MHz you should not exceed an ADC sample rate of 60 MS/s. If your hardware decimation factor is 16 it means your maximum device to host sample rate is 3.75 MS/s. You can still get a higher device to host sample rate by moving up the LO accordingly.
A couple of things I have noticed:
- The wideband antenna selector does not work. So for now youād better stay with the āLoā input
- The NCO is de-tuned by a change in the sample rate so once you have changed the sample rate you have to switch the NCO off and on else you donāt know where you are tuning anymore.
Best regards, Edouard.
2 Likes
Edouard,
Could you please change the round knobs to sliders or drop boxes. The knobs are imprecise for me. Or keep the knobs and make the values editable.
Thanks,
Lance
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@F4EXB - Edouard,
All good and I will try this again JUST on the Lowband (Lo) port on the LimeSDR. I know it worked before because I was tuning all the HF with the LimeSDR, but apparently I lost the recipe (which youāve given me now). Again, more to follow on that.
In terns of transmit, do you have any other suggestions how it can be made to sound clean? Iām looking for that ārecipeā, too, but have yet to land on it with all the combinations of sampling and decimation in the transmit side of SDRAngel. Anything you can offer there will be greatly appreciated, too.
73 de Marty, KN0CK
Hi Lance,
thatās fine if you point at the knob and use the mouse wheel. The interface is already pretty crowded and sliders take a lot more space. When there is a 1:1 relationship with the value it could be possible to make the value editable. Normally Qt has a āmaskā feature to constrain the value. I have to double check this however.
Best regards, Edouard,
@FX4EXB - Edouard,
Okay - looks like I have the recipe back again. I can receive fine on HF and can easily tune anywhere from about 1000 kHz to the top of the 10m band. So things are looking fine again.
40m was in pretty good shape for the LimeSDR here. Also, I saw in your picture that you have individual gain controls now? There are three adjustments to the left of the antenna selection that appear to be a different gain control than what I have with my SDRAngel version. Is that new? Please let me know -
Whatās your opinion on transmit? Please let us all know when you have a chance.
73 de Marty, KN0CK
Marty, you have USB3.0 dont ya ā¦
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Mike,
Sure doā¦All my PCās have USB 3.0 on them and Iām running at full throughput.
73 de Marty, KN0CK
Hello Marty,
latest version is 3.5.3. I see you run 3.4.5 which was released in May. A lot has changed since in particular with 3.5.1 that brought improvements for LimeSDR including individual gain settings.
This is how I get transmit working fine with voice on 40m. I had to push the gain to 10dB because it seems to have a lower gain in lower bands. On higher bands (VHF, UHF) I have to use a gain lower than ~3dB else it would saturate:
And the settngs on the SSB plugin (note the filter inversion: -2.7 and -0.3 kHz to get LSB):
I found not so easy to get the correct mic input level since each time I start transmit it seems it takes it to full power. I have used the āpavucontrolā (Pulse Audio Volume Control) utility to lower the mic gain. It also helps unmuting the input since it can also mute it occasionally.
My mic is a cheap headset + mic combo.
Best regards, Edouard.
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@F4EXB Edouard,
This evening I downloaded 3.5.3 and now have the same settings as you do for receive and transmit on 40m and was tuned to 7.200 kHz (per your GUI). When I set up my transmit to the same settings like you do, Iām seeing perfect SSB audio in the SDRAngel waveform monitor, but Iām not hearing any transmit from the LimeSDR to another receiver (Yaesu 857) tuned to the same frequency - - Yet, I see energy (the actual modulating waveform) on my digital oscilloscope (Siglent SDS 1072) - so I know the LimeSDR is outputting RF and itās SSB modulated. I just donāt hear anything in another receiver when itās tuned to the same frequency.
I have an HP 8593 spectrum analyzer that Iāll dig out tomorrow (right now itās midnight and I need to hit the rack for work tomorrow) and actually see what the output frequency is and if it seems to be modulated correctly according to that analyzer. But in the meantime, if you can tell me why I wouldnāt hear the LimeSDR transmitting in HF on the same frequency let me know. I have a notion that thereās going to be a coil issue like there was in receive for the transmit, too, to have the transmitter work more efficiently in the HF bands than where it is now. Iāll look into that tomorrow, too.
Keep me advised if you have any suggestions - This is the best audio waveform Iāve seen from SDRAngel in transmit yetā¦Just need to figure out why Iām not seeing the Lowband port (attached to an perfectly tuned antenna for 40m) get to another receiver in my shack.
73 de Marty, KN0CK
@F4EXB - Edourard,
Also, are these same settings that you use in HF (sampling rate and decimation) held to the same values? My guess is probably not because of the higher frequency and some interaction with the transmit settings but let me know. I have to think that the Low Pass filter setting is contingent on the band of operation and where it needs to fall. I would think that one would use the same FIR settings and that NCO is turned off above 30 MHz. Please let me know (or if itās easier send screenshots) what you use for V/UHF settings in transmit, too.
This and the earlier inquiry would be great to know. Iāll send pics of the spectrum analyzer display later when I get home from work - - there has to be something going on with the Lime in HF for transmit that hasnāt been cracked yet because Iām not hearing the faintest signal even when I run CW continuously and search for the Lime transmitting using my Tulip SDR or Yaesu 857 spinning the dial on either radio.
Keep me advised, Edouard, 73 -
de Marty, KN0CK
After reading Edouardās latest comment I think my last Tx check was saturated. I was experimenting with every setting besides gain.
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@Axeman - Lance,
Have you checked the RF output level on HF yetā¦? Iām going to this evening and wondering if youāve noticed anything about it. I had a heck of a time trying to hear what I was transmitting on HF but the audio looked GREAT in the waveform monitor. Iām going to make some measurements this evening to see what the RF output level is on TX1L (Lowband Port) and see if I can also see what the TX1H (Highband Port) level is, too.
More to follow - stay tunedā¦
73 de Marty, KN0CK
@Axeman - Lance & @F4EXB - Edouard,
Just so weāre not chasing down wrong rabbit holes, I did a calculation of the capacitive reactance of MN7 that is shunted across the primary of the output transformer for TX1L (and TX2L). According to my calculations at 40m (7.0 MHz) here is the reactance of that 2 pF capacitor MN7:
XC = 1/(2piFC) = 1 / (2 x 3.141592653 x 7 MHz x 2 pF)
= 1.14E+04 ohms (to 3 significant digits)
= 11,368 ohms
At 3 MHz this value is about 27K, and at 30 MHz the value drops to 2.6K. At itās design limit (1.9 GHz) the value drops to 41 Ohms.
So in view of that, I donāt think that the capacitance thatās there is going to cause any issues with the transmit channel and whatās there in inductance is just the transformer and itās designed to function at least to 4 MHz without any difficulties. So there will be NO need to modify the transmit strip hardware for the Lowband Port. The Highband Port is unusable for HF (and whoād want it anyway?) since it is strictly operational from 2 GHz to 2.6 GHz.
So that matter is cleared from my mind - - Now itās up to me to check this out on the spectrum analyzer this evening and see how it looks from 75m to 10mā¦Stay tunedā¦
73 de Marty, KN0CK