Many thanks to SWLing Post contributor, Julien, who writes with the following question:
First, thanks for your site !
I have a question about PL-365. It seems auto-scan works only in the range of 2,245-21,950 kHz. The ranges from 1,711-2,245 and 21,950-29,999 can only be scan manually.
Do you know the reason for this? Or a trick to auto-scan the other two ranges?
I do not know the reason for the auto scan limits, but imagine it could be a limitation of the SiLabs DSP chip inside–although this is merely a guess. My hope is that someone in our community can verify or perhaps help if they know of a work-around. Please comment!
Do people really find value in scanning on SW bands anyway? I’ve got a few radios that have the capability, and have even experimented with various ways of doing it (e.g. SNR, RSSI, etc) when retrofitting old radios with computer control, but never found it worthwhile – too many missed stations due to fading, noise bursts, being slightly off frequency, etc; too many false positives due to weird signals, harmonics/intermod, birdies, etc.
I’ve always seen it as more a marketing feature than something actually useful…
(That said, scanning stored memories is kind of useful – but that’s not what we’re talking about.)
I’ve made the exact same question to Anon-co since I’ve bought the radio there. The answer was that tuning above 21.950 should be done manually which does not work for me. I cannot go above 21.950MHz with the 365!
Synthesized receivers designed for broadcast should scan for these frequencies with options for regions 1, 2 and 3. https://www.itu.int/en/ITU-R/terrestrial/broadcast/Pages/Bands.aspx Restricting the tuning range speeds up the scanning. On this table broadcasting includes radio and TV.
CountyComm GP-5 SSB ( GEN 3 ) is same problem?
https://countycomm.com/collections/radio
I am thinking along the same lines as K.U. stated. No use scanning SWL spectrum where little to no broadcast activity exists.
https://en.wikipedia.org/wiki/Shortwave_bands#International_broadcast_bands
Looks like your scanning omits 120m and 11m. I rarely hear anything on 120m despite my QTH being near the tropics, and I am not sure any broadcasters even are on the 11m band anymore except maybe some localized daytime transmissions.
Don’t know why it omits the 120M band, but the 11M band is outside the scanning range of the Si4735 chip used in the PL-365. From the programming guide:
* Valid range: 149-23000kHz
* Recommended ranges: LW 153-279kHz; AM 520/522-1710kHz, SW 2300-23000kHz
edit: from what Julien says, it _doesn’t_ omit the 120M broadcast band – he says it starts from 2245kHz, which covers 2300-2495kHz.
Looks like the only SW broadcast band it omits is 11M, which is outside of the chip’s scanning range.
Appears I misread. Thanks for the FYI. 🙂
I don’t have the PL-365, but I have Tecsun PL-606. It scans only broadcast bands with some extension. All the rest is skipped. I Guess, the reason is faster scanning when sections with no or few broadcast stations are skipped.
Bandscan with Tecsun PL-365:
https://www.youtube.com/watch?v=U2wAD3UgvFs
The scan skips many more frequency ranges then the two mentioned in the article. For example, there is a long skip between 41 an 31 m bands. However, this scan covers 120 m and 11 m. Probably the scanned ranges depend on the firmware version.