SDR TRX Set

The TRX SoftRock Ensemble is a small 1W SDR transceiver for the KV band group. It is based on the success of SoftRock v.6.3 TRX, also from Tony Parks' workshop, KB9YIG. In principle, it can work with any modulation (determined by the software).

Getting the SDR Ensemble kit requires patience and internet tracking. All kits are sold online http://kb9yig.com/ , however, their availability is limited. Cena SDR Set i 74USD, which is very acceptable. Last year I managed to purchase one kit, assemble and operate.

The kit is sent in two envelopes. The reason is probably the higher postage for a larger or heavier package. In my case, there was a delay of several days in delivery, so we had to wait until the second envelope arrived. They contain parts for all four groups of bands 160m, 80m/40m, 30m/20m/17m alebo 15m/12m/10m, so when you're done, you'll have a portion left unused. However, the builder has to make a decision, which bands he is interested in.

The SDR Ensemble wiring concept uses USB AVR frequency synthesis control Si570. I.e, that the oscillator is smoothly retunable from the computer. The input and output I and Q signals are routed to the sound card. Depending on the type of sound card, it is thus possible to process up to 192 kHz of the frequency spectrum at one time.

There are mixers in both the RX and TX sections FST3253, The PA is equipped with two transistors BS170. The advantage is, that the frequency synthesis and AVR are powered via USB and isolated from the rest of the SDR TRX. It reduces the penetration of interfering products into the device.

Detail SDR TRX Ensemble 

Overall design including additional relay on RX/TX PA and XVRTThere are no adjustment elements on the PCB, the entire setting is done by software. It will make commissioning easier, but limits the parameters achieved.

The deployment and recovery procedure is available on the website http://www.wb5rvz.com/sdr/ensemble/ . It is definitely necessary to follow it, because the simplicity of construction is only apparent. The installation of SMT components is more difficult (blocking capacitors and IOs) and coil winding, resp. transformers. In addition, the double-sided printed circuit board is designed with very small areas for components, which makes high-quality soldering difficult. It requires a suitable micro-solder, tin, a holder and a certain hand.

Installing the printed circuit board will take approx. 10 to 15 hours of pure time. To revive it is necessary to have JS voltmeter an ammeter, and an oscilloscope and a second radio station are very suitable.

SDR TRX Ensemble back panelThe resulting utility value of SDR devices is largely determined by the sound card, computer and software. SDR Ensemble is no exception. I recommend looking for answers on the Internet and ignoring their illogicality. Practically every software also contains some errors. So what to avoid?

1, connecting cables and connectors, audio aj USB, they must be top notch. T.j. cables with good shielding and connectors precisely, best gilded. Cables should not be longer than necessary.

2, the power supply for the SDR must be stabilized with good filtering

3, don't skimp on the sound card. Although the sound cards on the motherboard "play" well, but they are not very suitable for SDR processing. If you also plan to broadcast, cards are supported PowerSDR

4, The choice of computer depends on the requirements, which you will have. In the minimalist version, you can also try P-III/1GHz, but if you want to use filters with better steepness or reduce signal delay, you need a powerful PC. Well, at least dual-core, several GB of RAM, graphics card. The operating system depends on the hardware, Windows XP and Windows are mostly used 7. If you have newer hardware, give priority to Seven, it has better work with the audio device than the previous versions of the OS.

5, SDR software in delí PowerSDR (including clones) and others. Programs like Rocky, KGKSDR, WinRad are simple and certainly functional, but there are certain limitations associated with them. PowerSDR is needed for more solid work, which is more complex, but offers better options. I bring GSDR to attention http://genesisradio.com.au/GSDR/new/, which in the current version already allows control of the si570 and according to my experience is significantly faster and more stable than PowerSDR

So if you have interest in experimentation on the KV and skill in building blocks, try SDR TRX Ensemble. The disadvantage is the difficult construction and the impossibility of achieving an optimal setting, the advantage is the price. Unless you're really serious about SDR, pay extra directly for the new Genesis G11 http://www.genesisradio.com.au/G11/ .