Many thanks to SWLing Post contributor, Jesse (W9JES) who writes:
I’ve been busy enhancing my Radio Shack DX-390. I added an IF-Out jack for my SDR, changed out the light for a LED, added a latch circuit for the light switch, added static protection, and disabled auto-mute. My blog with full instructions is at www.w9jes.com
Thank you, Jesse! Here are links to the various modifications Jesse has documented:
Many thanks to SWLing Post contributor, Jiri Kaplan, who writes:
Is it possible to modify the new (DSP) DEGEN DE1103 for VLF reception?
Like before, the old Degen version (without DSP), see these videos:
I wonder if instead of the DE1103 I should buy the PL-660 or PL-680?
I think DSP is worse and the old version can no longer unfortunately be purchased.
My main concern is good selectivity and sensitivity, I live in the city, there are many strong signals.
Thank you for your question, Jiri.
I’m certain you can’t use the same modification of the original DE1103 on the DSP version to achieve VLF reception. In fact, unless the DSP chip itself can be hacked, I imagine modding the DSP DE1103 for VLF would be quite difficult.
I hope more knowledgeable SWLing Post readers can comment with a definitive answer.
Regarding the choice between the DE1103 DSP and the PL–660 or PL-680? I wouldn’t hesitate to grab either Tecsun receiver over the DE1103 DSP. Check out my short review of the DE1103 DSP for more info about this particular model’s shortcomings.
You’re right about finding the original DE1103. I did create this eBay link that should help filter out the DSP models from the search results. At time of posting, there were no listings.
Many thanks to SWLing Post contributor, Troy Riedel, who shares the following tip. Troy writes:
While surfing the Net I found the following procedure that is said to “disable soft muting in Tecsun 300-series radios”.
I have a PL-390 and this has indeed seemed to work on it but I didn’t notice a difference with my PL-365.
Since I just found & tried this, I don’t know if this procedure must be repeated each time you use the radio? Maybe [Post readers] have heard of this before and/or have experience with it?
Here is the “reported” [supposed?] procedure that worked for the PL-390:
To disabling “Soft Mute” on Tecsun 300-series radios:
1. Select a shortwave frequency, preferably where there is no stations transmitting.
2. Tune down the frequency range with the dial, don’t tune up or it won’t work
3. Press the VF Scan button to let it automatically tune down
4. Tune down with the dial to stop the automatic scan. If the background noise is higher, then the “soft mute” / “dynamic squelch” has been disabled.
Thank you, Troy! I was unaware of this modification, but it seems easy enough to implement.
Post readers: Anyone have experience using this mod across the Tecsun 300-series receivers? Please comment!