Getting the SDR Ensemble kit requires patience and internet tracking. All kits are sold online http://kb9yig.com/ , but their availability is limited. The price of SDR Ensemble is 74 USD, which is very affordable. Last year I managed to purchase, assemble and operate one kit.
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 I had to wait until the second envelope arrived. They contain parts for all four groups of bands 160m, 80m/40m, 30m/20m/17m or 15m/12m/10m, so you will have a part left unused after completion. However, the builder must decide which bands he is interested in.
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Concept of SDR Ensemble
The SDR Ensemble wiring concept uses the si570 USB frequency synthesis AVR control. This means 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.
The mixers in the RX and TX parts are FST3253, the PA is fitted with two BS170 transistors. 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 of SDR TRX Ensemble
Overall design including additional relay on RX/TX PA and XVRT
Tips for a successful TRX recovery
The deployment and recovery procedure is available on the website http://www.wb5rvz.com/sdr/ensemble/ . Určite ho je potrebné dodržať, lebo jednoduchosť zhotovenia je len zdanlivá. More difficult is the installation of SMT components (blocking capacitors and IO) and coil winding, or transformers. In addition, the double-sided PCB 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 steady hand.
Installing the printed circuit board will take approx. 10 to 15 hours of clean time. To revive it is necessary to have JS voltmeter and an ammeter, and an oscilloscope and a second radio are very convenient.
SDR TRX Ensemble back panel
1, connecting cables and connectors, both audio and USB, must be top quality. I.e. cables with good shielding and precise connectors, preferably gold-plated. Cables should not be longer than necessary.
2, power supply for SDR it must be stabilized with good filtration
3, don't skimp on the sound card. Although the sound cards on the motherboard "play" well, they are not very suitable for SDR processing. If you also plan to broadcast, supported cards are suitable PowerSDR
4. The choice of computer depends on the requirements 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. So at least a dual core, a few GB of RAM, a graphics card. The operating system depends on the hardware, Windows XP and Windows 7 are mostly used. If you have newer hardware, give preference to Sedmička, it works better with the audio device than previous versions of the OS.
5, SDR software is divided into PowerSDR (including clones) and others. Programs like Rocky, KGKSDR, WinRad are simple and certainly functional, but there are certain limitations associated with them. For more solid work, you need PowerSDR, which is more complex, but offers better options. I bring to your attention GSDR 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
Summary
So, if you are interested in experimenting with KV and skill in assembling building blocks, try SDR TRX Ensemble. The disadvantage is the difficult production and the impossibility of achieving an optimal setting, the advantage is the price. If you are really serious about SDR, pay the extra for the new Genesis G11 http://www.genesisradio.com.au/G11/ .