Ten-Tec RX-350

The Rx-350 is relatively rare in Europe. The radio comes from the USA and has not been in production since ca. 2004. The big black box is a so called SDR-receiver. That means that some functions are software-based, e.g.,  the band width filters. If you open the radio, you wonder how it all works. There is only a motherboard with some parts on it.  Well, let's close the box again and let's see what the radio is capable of. Reception is from 100 KHz - 30 MHz in the modes AM, AMS, LSB, USB, CW, RTTY and FM. It has 34 DSP band width filters, 1024 alphanumeric  memories,  a spectrum display up to 2.4. MHz ( not in real time, though), auto notch, BPT (band pass tuning) etc…. so it's well-equipped. It even has a 12 KHz IF-output and so you can decode DRM with your PC.  But there is no keyboard for entering the frequencies. Instead, there is a keyboard/VFO control unit available which can be attached at the rear panel.

In view of the scant interior of the radio, I was eager to test the receiver. I compared it to the Drake R8B and the Reuter RDR50B. This receiver is very similar to the RX-350 because it is completely digital. For an antenna I used a tried and tested 35m- long wire. I was surprised to find out that the RX-350 is a very low-noise radio on AM and has a pleasant audio.  Thinking of the JRC NRD545DSP, the RX-350 is a real treat for your ears.  But there is more to come! Seldom have I heard such a clean SSB signal from a shortwave receiver. It is practically noise-free.  Sensitivity on shortwave is very good as well. On the other hand, the RX-350 has shortcomings on long wave and medium wave. It is rather insensitive and AM synchronous is not very stable, it loses the synchronisation  relatively fast.  Large signal immunity was mostly good,  except a few overloads above 10 MHz.

A rather strange thing is the display of the band width filters. If you select 6 KHz in AM, you end up at ca. 12 KHz. In order to use 6 KHz, you have to select 3 KHz.  That is very unique! It seems as if the band width of a sideband is shown. This strange feature was kept in several firmware updates. In SSB, the display of the band width is normal.

The quality of the case is typically American: inexpensive! If you knock on the case, there is a clattering noise and it sounds hollow.

But apart from that, the Ten Tec RXC-350 is a good shortwave receiver with an impressive SSB audio. Many thanks to an anonymous hobbyist  for putting this radio at my disposal.

posted 03.09.2012

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