Thank you to Mitsonobu Saitou for writing in and sharing with us a product that he has created which improves reception on of the Malachite DSP software defined radio and other shortwave radios by up to 20dB by improving the grounding. It appears to work by using the negative USB line as a ground via a modified USB cable with grounding clip on the other end. The product is available via Amazon Japan with international shipping.
The Malachite DSP is a portable battery powered software defined radio with built in screen. It is popular amongst shortwave listeners.
Saitou writes the following summary, and full details about the product are available on his blog (link uses Google Translate to translate from Japanese to English):
Today's item is "Dokodemo Earth KUN". This is an item to pull the ground wire from the charging connector of DCL radios and Mlachite DSPs.
The sensitivity of the receiver will be improved by strengthening the grounding. This is how I applied it.
It is easy to connect by pulling out the ground wire from the charging connector instead of the antenna jack.
It can also be used as a loop antenna by connecting the ground to the antenna.
We have confirmed the effectiveness of this product outdoors. Users who have used this item have experienced a significant increase in sensitivity.
Thanks to Thomas' SWLing Blog for bringing to attention the Silphase R1 SDR receiver. This is an upcoming high performance HF SDR receiver being manufactured in the EU by a Polish company called Silphase. The R1 appears to be targeting premium SWLer customers with a price of US$1199. However, they note that by the end of 2020 they will have a 25W transceiver option, and later a 100W transceiver option. The SDR is currently available for preorder only and the sign up form can be found at the bottom of their website.
The Silphase R1 comes with a 5" touch screen that shows a spectrum display, has dual VFO's, four speakers and a metal alloy enclosure. It also comes with a built in telescopic antenna, but external antennas can be connected with the F connector. The tuning range is just the HF bands from 0.1 - 30 MHz and the ADC resolution is 16 bits.
Over on the swling.com blog, Thomas has uploaded a review of the TitanSDR Pro that was published in the May 2015 version of The Spectrum Monitor online magazine. Although the TitanSDR pro software defined radio is an expensive (1,380 EUR for the basic / 1,970 EUR for the PRO), it may be of interest to those looking to go further into the short wave listening hobby. The TitanSDR is a high performance 9 kHz to 32 MHz receiver with 16 built in preselectors and a bandwidth up to 2.1875 MHz. It’s main markets appear to be government intelligence and military, but it also finds good use in general short wave listening.
Thomas reviews the TitanSDR positively, liking its easy to use software and its superb sensitivity, but noting that it’s high price may be a bit off putting.
Also, in the current June version of The Spectrum Monitor magazine Thomas also reviews the SDRPlay, a $149 USD HF capable radio, also giving it a favourable review.