New functionality of the radio receiver Arinst SDR Dreamkit V1D
1. Recently a new version of SDR Console has been released, which adds support for our receiver. Thanks to Simon Brown. To work under the control of this program, you need to turn on the receiver. Go to the Device tab and click on the PC SDR button. If you do not have a driver for the receiver installed, then you need to download and install it from arinst.net. Launch SDR Console. We select Select radio - our receiver. The required bandwidth and press start. In the HOME tab, you can select the span and the IF gain.
2. For the convenience of controlling the device, we decided to add the ability to connect an external mouse - both wired and wireless. The instructions for revision are posted on the arinst.net website. To connect a mouse, you need to purchase a mini USB OTG adapter, its cost is about 2 dollars. The next update will add this USB HOST HID mode to support the mouse.
3. To support the external preselector, an instruction will be posted, which describes the creation of a preselector based on Arduino. To switch the ranges, code manipulation is used with the key of the external power supply 12 V. In the receiver menu, it will be possible to set the frequencies of the preselector section and the attenuation. The preselector is not planned to produce, but you can make your own based on the arduino board.
4. In the event of failure of the input RF amplifier due to electrostatics or other reasons.
Its replacement is required. Replacement instructions are also available on the arinst.net website.
5. IF gain: When changing gain, the signal scale is tied to the input level. Consider this on a generator:
With a high level of external noise, the noise shelf will also rise. On-screen display enhancement level.
6. The minimum display frequency is now 0 Hz. Due to LPF of quadrature channels with a cutoff frequency of 2.5 MHz, the minimum receiving frequency is about 300 kHz.
Let's show this on a generator.
7. Explanation of the screens and the accuracy of the frequency adjustment viewfinder. Due to the high sampling rate, the maximum display bandwidth reaches 6 MHz, which is especially useful when searching for radio signals of interest. The 6 MHz band is called the baseband. But for the simultaneous demodulation of such a wide bandwidth, the performance of the microcontroller is not enough; for this, two-stage signal decimation is used. When demodulating WFM - decimation is applied to 12. In this case, the maximum displayed bandwidth 500 kHz is called the IF1 bandwidth. If the modulation is narrower, then decimation by 16 still occurs, the display bandwidth of IF2 is 31250 Hz. You can select the bandwidth to be displayed on the screen for both BB and IF1. The display accuracy of the viewfinder is tied to the screen resolution and for narrow bands is about 100 Hz. If you need to view narrow bandwidths less than 1MHz (BB) then you should turn off the BB spectrum display on the screen and select the IF1 display. With IF1, you can choose the bands even narrower - 450-50 kHz. If you need to fine-tune the signal spectrum for narrow bands, you should also display IF2 on the screen by the location of the signal it will be clear how accurately you have tuned.
8. Graph display settings - the display has many settings that can be selected in the Display tab. Due to the limited size of the screen, for the most accurate display of the signal - in the settings you can select the display range - 20-90 dB - in fact, this is the display scale. And the middle level can be changed with the stylus by moving the scale. For a smoother display of the spectrum, in the Display tab there are adjustments to the attack and fall times for each graph, that is, they are configured individually.
9. Setting the frequency - when setting the frequency through the menu, to erase the previous value, hold down the erase button - after 1 second the frequency entry field will be automatically cleared.
10. Turn on / adjust the threshold squelch. Squelch - enabled in the Audio tab, displayed as a red bar on the S meter. By dragging the strip, you can adjust the level of unlocking / locking of the audio path.
11. Noise reduction on the Audio tab - you can also get into it by holding down the NR button on the main screen. The main setting - noise reduction level - Threshold - determines the relative level of spectral components, which will be suppressed to the depth Depth. The rest of the settings allow you to reduce the distortion introduced by the noise suppressor, are selected individually.
12. When you select narrowband demodulations (all except WFM) in the BAND tab, the Noise Blanker menu opens. Operates on IF1, and cuts signal spikes that lead to severe distortion during demodulation.
13. Setting the AGC for narrowband demodulation.
In the Audio AGC tab - the level of the AGC activation threshold, the AGC slope and the settling time. All adjustments are individually configurable.