On Wed, May 27, 2020 at 07:53 PM, Max Italy wrote:
Actually there have been quite a few FSL's hard wired into DSP-chip Ultralight radios, and some of them work quite well. Most of the attempts have been with the Tecsun PL-380, which seems to tolerate an FSL's powerful RF output as long as a small coil is used (3" or less diameter).
I've attached a construction file for the hard wired 3 inch FSL Tecsun PL-380, of which about 10 were made by me and other DXers back in 2016. A couple of 2 inch FSL Tecsun PL-380's were also made, one of which I sent to Hiroyuki Okamura in Japan. These hard wired FSL experiments were attempted with the CC Skywave Ultralight, but their Si4735 DSP chips were fried pretty quickly. A PL-380's Si4734 DSP chip was also fried when a larger (5 inch) FSL was hard wired in place of the loopstick.
The hard wired 3" and 2" FSL Tecsun PL-380's work quite well, but the main drawback is that they require the very rare Russian surplus 100mm x 20mm x 3mm ferrite bars, which haven't been available commercially since 2012. These are the same lightweight ferrite bars used in the 5 inch "Frequent Flyer" FSL antennas, so the demand for these rare ferrite bars is extreme.
73, Gary DeBock (in Puyallup, WA, USA)