Some time ago I purchased an RTL ‘TV’ USB tuner. I was immediately impressed by the way whole chunks of the RF spectrum are visualised; tuning as simple as clicking a signal of interest plus ‘brick wall’ filters by the drag of the mouse. However, the novelty did soon wear off due to the lack of HF coverage.
When a colleague (Graham G6IXM) offered me an SDR(X) I jumped at the chance to have a play. This interface is based on the RTL but contains an upconverter plus pre-filters, covering 0-1850MHz. Performance was really very good indeed and I had hours of fun playing with this under both GQRX and GnuRadio (Linux). However, is still lacked something: TX.
Spurred on by the incredible performance of the SDR(X) but not wanting to get too spendy, I researched a few of the lower end SDRs available. Whilst there’s been several recent developments, the SoftRock RXTX Ensemble seemed highly respected and has been available long enough to develop a good user base.
A few emails to Tony KB9YIG later and I had a built SoftRock RXTX crossing the pond to the UK. I did consider a kit but seeing the complexity (and size of the SMDs) I thought better of this. Attempting to keep costs down I purchased a cheap eBay USB soundcard (48KHz only) – figuring I can always upgrade later if I wish. In order to re-use my existing shack mic, I also ordered a £10 XLR-USB cable (a mic cable including pre-amp and sound card).
The $89 SoftRock and USB Soundacrd
I decided to go with Windows first as despite being a Linux person, there seemed to be a few potential ‘gotchas’ and I was keen to play, not fight configuration issues. On initial startup (HDSDR) I noticed I could only see the LO signal. A post to the SoftRock group later and I soon realised I’d connected the wrong SoftRock ‘out’ to the wrong soundcard connector. Feeling a complete numpty, swapping cables made 40m spring into life.
The bands the last two days have been appalling so I’ve not had a single QSO; although sending CQ in CW on 40m did net a couple of spots on the Reverse Beacon Network (Wales and Germany). It lives! What a fantastic bit of kit it is, too!
Spotted via the Reverse Beacon Network
(Click to Zoom)
The SoftRock RXTX Ensemble is available from Tony KB9YIG via http://fivedash.com/ in both kit ($89) and pre-built ($124) form. The device is supplied with an external LPF which must be built before using TX. Output power is stated as 1W but using my power meter and a dummy load, I measure 3W on CW keydown (40m). Build quality is absolutely superb and I found Tony incredibly helpful. As expected, I had VAT and a handling fee to pay before collection in the UK but this IMO is still tremendous value.
HDSDR (Windows)
When band conditions improve I can see the SoftRock RXTX Ensemble rapidly becoming my radio of choice. Whilst I love my FT847, this has opened my eyes to a whole new way of operating. I fear there’s no way back. I’m addicted.
Huge thanks to Tony KB9YIG for making this not only possible, but affordable.
Steve M0SPN
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