This page contains images of signals heard on the HF bands on my Tentec Orion II. Some of these images were taken from the display produced by SpectraVue software, which displays the IF signal from the Orion II via an SDR-IQ receiver. The PSK images were captured from the WinWarbler program. If you received an OO report from me regarding a problem with your signal, check the signal images at the bottom of this page and match the number with that on your OO report.
On the following SSB images, the horizontal grid lines are spaced at 1 KHz and the filter outline is set to 2.8 KHz in the SDR-IQ. The first two images illustrate very good signals with proper bandwidth.
This image is of a strong (S9) LSB signal heard on 40M. Note the signal bandwidth in relation to the 2.8 KHz filter outline.
And here's what over-modulated SSB signals look like. Distortion products make the bandwidth of the signal greater than necessary, interfering with adjacent frequencies and resulting in splatter above and below the frequency, sometimes several KHz away.
Following are examples of good and bad PSK31 signals. In the bad images, note the presence of multiple sidebands on each side of the carrier. You should be aware that not all PC soundcards are equal in terms of IMD and your PSK IMD level could be high even though you may not be overdriving your transmitter. Here I use an E-MU 0202 USB soundcard (external box actually) that has low distortion ratings and this card is often used in receive panadaptor setups, such as with LP-Pan. If you're using a laptop internal sound chip for PSK, consider moving to a USB attached card of higher quality. PSK signals with a high distortion level WILL interfere with adjacent frequencies.
This is a good PSK31 signal heard on 20M. Note the lack of sidebands. This is most clear in the beginning of the signal where just the two unmodulated tones are present.
Another example of a good LSB signal.
And here's a bad PSK31 signal. Note the multiple sidebands and how the sidebands to the right of the signal are overlaying someone else's signal.
This one isn't quite as bad, but there's significant energy in one pair of sidebands.
Here's a random sample of 20M PSK31 signals this afternoon. #1 earns a "terrible" ranking with it's multiple sidebands, one undoubtedly causing interference with the weaker signal just to the right. #3 is a close second, as is #4. Note #2, which is about the same signal strength as the other three, but with barely detectable sidebands.
Here's a rather wide signal on 20M USB. The tick marks on the horizontal axis are 1 KHz apart. This guy was about 8 KHz wide.
This is one of the worse SSB signals I've seen lately - 10 KHz wide, and the splatter heard a considerable distance up the band.
The following images recently received Official Observer reports for poor signal quality. They're identified by a three digit number which was included on the OO report card. If your image is here, please take some time to figure out why your signal looks as it does - maybe it's as simple as having your audio gain too high, or perhaps you have compression turned on (not a good idea).
#332 - Lower signal is N6****, upper is K0****
A superb signal from KJ6MQE. Note the complete lack of extraneous sidebands.
A word about signal quality from K8AC
#335 - N2**** In this image, all the vertical bands covering the middle of the image are from the signal on 14.072. There were no spurious signals on the high frequency side. The spurious sidebands pretty much obliterated almost 2 KHz of the band. The station originating this signal is encouraged to stay off of PSK31 until the problem is resolved.
#336 - WA1**** Filter outline is 2.8 KHz wide - signal observed was 6-7 KHz wide.
#337 - N9**** Multiple sidebands - probably audio gain too high or compression on.
#338 - WA4**** Exceptional number of sidebands, extending out around 250 Hz above and below the signal.
#339 - KR4**** The offending signal is the PSK63 signal near the right side of the image. All the sidebands to the left, stretching over 1 KHz, are from that signal.
#340 - N8**** below, WA1*** above. Offending signal is about 400 Hz wide.
#342 - N2*** Many strong sidebands - very wide.
#343 - NS4*** - Very broad signal - note the 2.8 KHz filter bandpass outline and signal with good bandwidth at the right.
#344 - K9*** - Very high IMD, lots of sidebands
#345 - KA2**** Very high IMD
#346 - AJ8**** - High IMD - wide signal
#347 - KA1** - Extremely high IMD, spreading over more than 1 KHz. The offending signal on the left side is generating all of the sidebands seen across the image.
#348 - KX1** - Very high IMD
#349 - KD9** high IMD, wide signal
#350 - K1***
Very high IMD - extremely wide signal
#351 - K0**/W0***
High IMD - broad signal
#352 - KB1***
Very high IMD, broad
#353 - KA3*** (CW mode)
I heard the key clicks from this station while tuned a couple of KHz down the band. The signal in question is the one just to the right of center, just above 7.029. The signal peak is just above S9 and the peaks to either side of the carrier (just over 200 Hz away) are the click sidebands, which are between S3 and S4. In addition, the signal is broader than others, with a "rushing" sound observed above and below the carrier. Note how the bandwidth of this signal compares with that of another strong, but clean signal on the left side of the screen.
#354 - KX2*** (USB mode)
Total bandwidth of this signal was 10 kHz. The shaded filter bandwidth shown represents 2.6 kHz. The station was observed on this frequency and on 14.199 shortly thereafter and the same bandwidth was noted. When I tuned above or below the frequency, the extraneous sidebands sounded like splatter from over-driven audio.
#355 - N2** The signal in question is directly below the yellow triangle near the bottom of the screen. The wide band of distortion on the low frequency side of the signal extended over 1 KHz, causing extreme interference to other stations. This is clearly not a simple case of IMD caused by overdriving the audio.