Category Archives: Featured
Ham Radio Science occasionally get emails from our readers on suggestions for a good reasonably priced HF SDR radio that won’t break the bank. So, we spent a little time investigating what was available in the under $300 price range. Frankly, there is not much to be found with the exception of a few kits. The kits are great learning tools, but some of our readers may not prefer trying to build a kit that includes tiny sma parts. Also the kits and some of the less expensive SDR radios are still sound card based and we were really looking for a direct sampling receiver. The $249 Afedri SDR-Net HF SDR met our requirements and more. The Afedri Net-SDR allows for connection to your pc via an USB interface and what truly puts the Afedri SDR-Net in a class of its own is the ability to connect via TCP (Lan connection). After looking into the very positive comments on the internet regarding the Afedri SDR-Net, we thought it would be well worth investigating this amazing little budget HF SDR receiver. The Afedri SDR-Net is made by Alexander Trushkin 4Z5LV and is available in a case for $249 or as a board for $199 from Alexs’ website. We highly recommend the version with case, since the case is very well constructed. We contacted Alex and he sent us out a sample Afedri SDR-Net Vers. 2.3a to take a look at. We have been using the Afedri daily for HF monitoring for about a month and have been very impressed with what you get for the price.
Editors Note – Apparently SDR Touch is temporarily off the Google Play Store. Martin hopes to have it back soon. You can still get SDR Touch directly from Martin, until the issue has been resolved. (See Martins comment below). In the meantime, you can download SDR Touch from Martin’s Website.
Ok, this was bound to happen sooner later. With the introduction of some very powerful Android tablets last year in the $199 price range like the Nexus7, Kindle Fire, and the Samsung Galaxy Tab, combined with the availability of the inexpensive RTL2832U SDR dongles, it was inevitable that some would do a “mashup” of the two sooner or later. The result is an application called SDR Touch by Martin Marinov. At this time the application is still in the development phase, but is now available from the Martin’s Website. For that reason, any thing we say here may change in the next 5 minutes. We contacted Martin and he kindly sent us out the current fully functional version of SDR Touch to take a look at. We were impressed with Martins’ work.
Recently, the good folks at Per Vices sent us out a Noctar SDR radio card to take a look at. The Noctar card began shipping earlier this month. Normally we discuss cheap SDR radio gear at HRS, but we felt that the Noctar is a break through SDR product that would be worth investigating further. In some respects the Noctar does qualify as cheap SDR when compared to its competition in the wide coverage SDR radio category. The Noctar card has a receiver range of 100KHz through 4GHz, with the a bandwidth up 250MHz. The Noctar card alone is sold for $749 or as a kit for $849 which includes two circuit board type log periodic antennas that cover 650MHz to 6500MHz and SMA cables. The other very interesting fact about the Noctar is that it can also transmit from 100KHz to 4GHz up to a bandwidth of 250MHz. The nearest competition in this category of SDR radios can cost easily two to three times more than the Noctar.
As you know, SDR radio basically consists of two components, the radio hardware and the software used to process the signal. As SDR radio hobbyists we typically spend a lot of time looking into the specs of the hardware, but we don’t but as much consideration into the software side of things. The software can be just as important as the hardware we choose to get good performance from a SDR radio system. We often turn to some of the free software offerings to get started in SDR hobby. While there is absolutely nothing wrong with that and we greatly appreciate the work these authors has put into their efforts. However, you have to keep in mind that some of these programs use DSP (Digital Signal Processing) engines developed for SDR use that have been handed down for many years and have only been improved slightly over their original incarnations. With that in mind, the developers at SDR Applications set out to create a new high performance DSP engine for better SDR performance from your SDR hardware. That product is now called Studio1 and is distributed by Woodbox Radio. Studio1 is not a free application. However, this is a good thing because unlike the free offerings, this means that for this to be a viable product the developer will have to be committed to it’s continual improvement and provide support for its customers. In a nutshell Studio1 has gotten a good start on meeting those goals.