Alinco DX-SR9 Hybrid SDR Transceiver Review
Ok, time for a little negativity here. There are some some idiosyncrasies with the IQ output that is worth mentioning here. These are some things just to note and do not hugely detract from using the DX-SR9 as an SDR radio. Frankly most beginners won’t even notice them that much. First of all, it was already mentioned that the DX-SR9 IQ output is inverted. This in no way is a problem but something to be aware of when using 3rd party SDR software. Just be sure that you check the swap IQ channels box in the software. The other issue, you will probably notice right away. Due to an imbalance in the IQ output allegedly caused by the filtering used in the DX-SR9, you will notice that the right side of the waterfall is weaker than the left. Not that you won’t see plenty of signals on that side of the display, they will just be displayed in a dimmer color. This doesn’t affect the signal and clicking on a signal on the right side of the display will allow the signal to be heard normally. More of a cosmetic issue really. This is not a fault of KGSDR, since all the 3rd party SDR programs showed similar behavior. KGTRX does offer a work around by allowing a you to not show the right side of the waterfall area in the IQ tuning settingd. Of course this only allows you to see 24KHz of the tuning area. Again this is not particularly a huge problem, so it’s really not necessary to use this setting. You can also adjust the waterfall gain settings and reduce this effect somewhat.
A possible side effect of this imbalance is that ghosts of very strong signals that show up in the left side of the waterfall will often be shown in the right side of the waterfall. This may also be exacerbated by your particular soundcard, so your mileage may vary on how much of this you will see. When in SSB mode if you click on one of these images, you will not be able decode the audio correctly so you know that the displayed signal is just an image of a stronger signal that is booming in on the left side of the display. They way to combat this is to reduce the DX-SR9’s gain to -20. You won’t really miss anything by reducing the gain and it will help getting rid of some of these false signals. However, even with the reduced gain, you may indeed still notice the occasional false signal in the far right one third section of the waterfall display. The good news that if you use HDSDR, you can pretty much eliminate this small annoyance by adjusting the raw and fine settings of the amplitude settings in the Options / Input Channel Calibration for RX. Just tune to area where you see a strong signal being duplicated on both the right and left sides of the waterfall and fool with the sliders until the right hand signal is significantly reduced or gone.
Using the DX-SR9 with 3rd Party SDR Software
Fortunately thanks to the development of an ExtIO.dll file for the Alinco DX-R8 and the fact that the DX-SR9’s serial port command structure is the same, you can very easily use HDSDR and Studio 1 SDR programs for receive. Just download the the ExtIO file for the DX-R8 and using a text editor configure the included ini file to match the com port setting for your EWR-7 cable. Drop the ExtIO and ini file into HDSDR’s or Studio 1’s main directory and you will be ready to go. Both programs will allow you to set the center frequency of the DX-SR9. All you need to do is set the IO settings for the soundcard.
Using 3rd Party Digital Mode Programs
Thanks to DVOX, you can to this fairly simply. However you may need to acquire some virtual cable software for audio routing. Since everyone’s needs and settings my be different here, this will just be a general discussion of how to achieve this. First grab some free virtual audio cable software if you need it. VB-Audio Cable is an excellent and easy to use virtual audio cable program. The first cable is free, but if you need a second cable then you will need to make a donation in the amount of your choice to the author. What you are going to need to do at minimum is use the virtual audio cable to route output audio of the SDR software to the audio input settings of your digital mode software. Now, this will mean you may not hear the audio from the radio, but if you want to you can. You will have to go into the input audio settings properties on your PC for the virtual cable and set the listen mode to on. Make sure you digital mode software is set to output to the appropriate soundcard input settings that will send audio to the DX-SR9’s Mod jack. Make sure the DX-SR9’s DVOX setting is one. Check your digital mode software and check if CAT controlled transmit is off. Some programs won’t go into transmit with the CAT control on. You should be able to use the digital mode’s transmit feature to key the radio, not the SDR software. KGTRX might be the easiest program to use this way, since it will automatically match the transmit frequency to the currently selected receive frequency as well as the proper transmit mode. HDSDR and Studio 1 cannot set the proper transmit mode on the DX-SR9. Remember, you had to set it to FM mode to get into the SDR Mode. Trying to transmit using these programs as the receiving front end will leave you transmitting in the wrong mode or frequency. Not good.