Re: Tecsun PL-310 vs PL-380
When both the original PL-310 and PL-380 were introduced by Tecsun in 2009-2010 they were fully reviewed (at http://www.mediafire.com/file/w4yuzhj2kyz/Tecsun_PL-380_Review.pdf/file for the PL-380, and http://www.mediafire.com/file/q8pbn34i1nangl4/The_Tecsun_PL-310.pdf/file for the PL-310. Unfortunately, since that time Tecsun has followed the tendency of many Chinese companies to cut the quality of their products in order to increase profits, resulting in new digital quirks (and other issues) in these models.
In 2012 Tecsun removed the shielding around the Si4734 DSP chips in their PL-380 models (and probably in their PL-310's and PL-606 models as well), resulting in a digital whine whenever the display is grasped by the hand. The PL-310 was stripped down into a completely different model to make the lower quality PL-310ET, as described in the 2015 Ultralight Radio Shootout (posted at https://swling.com/blog/2015/03/gary-debocks-2015-ultralight-radio-shootout-review/
In my opinion neither the newer PL-380's nor the PL-310ET are really suitable for important overseas DXpeditions, which are much more demanding because of the rough environments, temperature extremes and travel bumps. The newer C.Crane Skywave and Skywave SSB models lack some of the digital search features of the Tecsun models but have much higher quality overall, including a new DSP chip which outperforms the Tecsun Ultralights in the most important categories (MW sensitivity, freedom from internally generated heterodynes and superior 1 kHz DSP audio). Whenever a friend goes with me on an important overseas DXpedition I always provide them with a "supercharged" CC Skywave model, which is fully capable of tracking down great DX all by itself (such as 1000-Radio Record in the Cook Islands, 1431-Djibouti in Hong Kong, etc.). Unfortunately the CC Skywave models do cost significantly more than the Tecsun Ultralights, but the increased cost is worth it, in my opinion. For someone who cannot afford US $90 for a new Ultralight, the newer PL-380 would be OK if you don't mind the significant digital quirks.
73, Gary DeBock (in Puyallup, WA, USA)