Hi everyone
I’m new to the whole SDR thing and have recently dipped a toe into the SDR water by using an RTL SDR dongle (2832/R820T) and a NooElec HF upconverter. I’ve tried a few software packages including the popular SDR#, but I very much prefer HDSDR, which is the reason for my post here.
I’ve been using HDSDR for a couple of weeks but something is really confusing me about it, and I’ve spent almost 2 weeks searching online for an answer which I haven’t been able to find.
So, can some of the experts here tell me how I actually (correctly) tune the receiver using the digital displays in HDSDR? Do I use the LO display for the actual tuning, or the Tune display?
I noticed after using the program for a few days that some of the frequencies were off. Here’s an example – it’s quite difficult to explain but I hope I can explain it clearly enough to make sense. Apologies in advance if it’s a little long-winded, but it’s a little complicated to explain.
If I use the Frequency Manager to go to, say, the 19m broadcast band it will set the LO frequency to 15430 kHz and the Tune frequency display to 15450 kHz. If I then look at the waterfall and spectrum displays I can see, for example, the Radio Kuwait signal on 15540 kHz, but the scale below the spectrum window (and the numbers which come up beside the pointer) show it as 15535 kHz, which is wrong (-5 kHz). When I click on it to tune it in, the Tune frequency display also shows it as 15535 kHz.
Now, if I start again and instead of clicking on the waterfall or spectrum display to tune in the signal I instead use the LO display and click up until the Tune frequency display shows 15540 (LO shows 15520), it seems ok. What happened next is that I accidentally clicked the LO frequency down by 100 kHz (from 15520 to 15420), and to compensate, I then increased the Tune frequency (which had also dropped by 100 kHz) by 100 kHz to take the Tune display back up to 15540. This didn’t work. There was no sound except for static, but the Tune display and spectrum display both showed that 15540 WAS tuned, however the signal was now showing as being on 15525 kHz!
Adjusting the LO frequency display only changed the frequency displays for both the LO and Tune frequency - the actual waterfall display didn’t change and the signals remained where they were – only the spectrum frequency display changed to match the LO and Tune frequency displays, but the actual tuning did NOT change, i.e. the station wasn’t received, only static.
Clicking on the signal in the waterfall or spectrum display retuned the station, but on 15525 kHz, which is 15 kHz below the correct frequency.
And now something else interesting – the station remained tuned in perfectly despite changing the LO frequency control. It remained tuned in from LO 15407 (Tune 15512) right up to LO 15462 (Tune 15567), some 55 kHz.
I hope that all made sense.
Is this a bug or am I doing something really stupid, as it’s REALLY confusing the heck out of me
I’ve already been through the initial calibration/setup stage before beginning to use HDSDR, and it seems accurate to within less than 100Hz on all the aeronautical SSB stations I use, so I don’t think it’s the calibration which is the problem. I have upgraded HDSDR to v2.62 and still get the same.
I’m using this on an old spare PC running Windows XP SP3, but spent some of the weekend installing it onto an old XP SP3 laptop too (with the XP version of Zadig) and also onto a Windows 7 laptop, and it’s the same on them both. I also swapped the dongle and upconverter with a friend’s and am still getting the same thing. He’s a newbie too so can’t help.
Am I missing something here or just using HDSDR wrongly? I’ve read a lot about HDSDR over the past couple of weeks and from what I’ve read I don’t think I’m doing anything wrong, but I’m unsure if I’m using the LO and Tune displays correctly as I haven’t been able to find out anything about their use. I’ve been using the LO as a rough tuner and fine-tuning with the Tune control, keeping a bit of distance between the two frequencies.
It seems that if I enter the frequency directly via the keypad on the keyboard that it’s ok, but only if I haven’t had the above problem. It seems to be a problem when using the mouse to change the LO or Tune display.
I would so much appreciate any advice from anyone who knows as it’s starting to put me off as I don’t know for sure what frequency I’m actually tuned to, and only stumbled upon this problem by accident.
Many thanks for any advice.
I’m new to the whole SDR thing and have recently dipped a toe into the SDR water by using an RTL SDR dongle (2832/R820T) and a NooElec HF upconverter. I’ve tried a few software packages including the popular SDR#, but I very much prefer HDSDR, which is the reason for my post here.
I’ve been using HDSDR for a couple of weeks but something is really confusing me about it, and I’ve spent almost 2 weeks searching online for an answer which I haven’t been able to find.
So, can some of the experts here tell me how I actually (correctly) tune the receiver using the digital displays in HDSDR? Do I use the LO display for the actual tuning, or the Tune display?
I noticed after using the program for a few days that some of the frequencies were off. Here’s an example – it’s quite difficult to explain but I hope I can explain it clearly enough to make sense. Apologies in advance if it’s a little long-winded, but it’s a little complicated to explain.
If I use the Frequency Manager to go to, say, the 19m broadcast band it will set the LO frequency to 15430 kHz and the Tune frequency display to 15450 kHz. If I then look at the waterfall and spectrum displays I can see, for example, the Radio Kuwait signal on 15540 kHz, but the scale below the spectrum window (and the numbers which come up beside the pointer) show it as 15535 kHz, which is wrong (-5 kHz). When I click on it to tune it in, the Tune frequency display also shows it as 15535 kHz.
Now, if I start again and instead of clicking on the waterfall or spectrum display to tune in the signal I instead use the LO display and click up until the Tune frequency display shows 15540 (LO shows 15520), it seems ok. What happened next is that I accidentally clicked the LO frequency down by 100 kHz (from 15520 to 15420), and to compensate, I then increased the Tune frequency (which had also dropped by 100 kHz) by 100 kHz to take the Tune display back up to 15540. This didn’t work. There was no sound except for static, but the Tune display and spectrum display both showed that 15540 WAS tuned, however the signal was now showing as being on 15525 kHz!
Adjusting the LO frequency display only changed the frequency displays for both the LO and Tune frequency - the actual waterfall display didn’t change and the signals remained where they were – only the spectrum frequency display changed to match the LO and Tune frequency displays, but the actual tuning did NOT change, i.e. the station wasn’t received, only static.
Clicking on the signal in the waterfall or spectrum display retuned the station, but on 15525 kHz, which is 15 kHz below the correct frequency.
And now something else interesting – the station remained tuned in perfectly despite changing the LO frequency control. It remained tuned in from LO 15407 (Tune 15512) right up to LO 15462 (Tune 15567), some 55 kHz.
I hope that all made sense.
Is this a bug or am I doing something really stupid, as it’s REALLY confusing the heck out of me
I’ve already been through the initial calibration/setup stage before beginning to use HDSDR, and it seems accurate to within less than 100Hz on all the aeronautical SSB stations I use, so I don’t think it’s the calibration which is the problem. I have upgraded HDSDR to v2.62 and still get the same.
I’m using this on an old spare PC running Windows XP SP3, but spent some of the weekend installing it onto an old XP SP3 laptop too (with the XP version of Zadig) and also onto a Windows 7 laptop, and it’s the same on them both. I also swapped the dongle and upconverter with a friend’s and am still getting the same thing. He’s a newbie too so can’t help.
Am I missing something here or just using HDSDR wrongly? I’ve read a lot about HDSDR over the past couple of weeks and from what I’ve read I don’t think I’m doing anything wrong, but I’m unsure if I’m using the LO and Tune displays correctly as I haven’t been able to find out anything about their use. I’ve been using the LO as a rough tuner and fine-tuning with the Tune control, keeping a bit of distance between the two frequencies.
It seems that if I enter the frequency directly via the keypad on the keyboard that it’s ok, but only if I haven’t had the above problem. It seems to be a problem when using the mouse to change the LO or Tune display.
I would so much appreciate any advice from anyone who knows
as it’s starting to put me off as I don’t know for sure what frequency I’m actually tuned to, and only stumbled upon this problem by accident.Many thanks for any advice.
