Category Archives: Shortwave Radio

Dean spots a radio in Pulp Fiction and shares a little shortwave by train

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Many thanks to SWLing Post contributor, Dean Bonanno, who writes:

Hi Thomas –

I was re-watching one of my all time favorite movies yesterday, Pulp Fiction, and noticed a radio in a scene for a second or two [see image above]. It went by so fast I thought it might have been a Trans Oceanic 7000 at first but upon looking backing and stopping film, it is an Arvin Radio. I was wondering if anyone knew model/year.

I also included a video clip of Radio Tumbril Encore from aboard Amtrak’s Capitol Limited for exactly a week ago. I did some DXing while crossing the country by train. The video is near Pennsylvania/Maryland border (near you perhaps) on WRMI 15770 in 1300utc hour (enlarge video you can red it on PL 880 screen). I have another video while pulling into Cumberland, MD. Continue reading →

Grayhat’s NCPL (Noise-Cancelling Passive Loop) antenna “tweak”

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My NCPL antenna

Many thanks to SWLing Post contributor, Grayhat, who shares the following modification he made to a Noise-Cancelling Passive Loop antenna last year. He’s kindly allowed me to share his notes here, but apologized that at the time, he didn’t take photos of the project along the way and recycled many of the components into yet another antenna experiment.

Grayhat writes:

Here’s a simple tweak to the NCPL, made easy for anyone. Let’s start with the commercial NooElec 9:1 balun version 1 (not 2) … made in USA.

Look at the schematic of the balun:

Cut the R1 (0 Ohm resistor – jumper) so that the center tap of the transformer won’t be connected to ground, then solder a short piece of wire to the tap.

The first pic (top) shows the balun seen from top side, the arrow indicates the small hole going to the transformer tap.

This pic shows the bottom of the board with the trace to cut and the spot for soldering the tap wire (needs cleaning with a bit of sandpaper to remove the cover paint). The solder is as easy as 1-2-3 once the trace is cut and the spot cleaned just insert a wire from the top of the board and solder it to the bottom and there you go!

Build the NCPL using “fat” coax (RG8 will do) with the top cross connection.

NCPL modification schematic

Side note: the top “cross connection” is the weak point, so it would be a good idea putting a short piece of (say) PVC pipe over that point, the piece will also help suspending the loop or sticking its top to the support pole, as for the feedpoint, a small electrical junction box will fit and protect the tiny balun from bad weather

Now the difference: connect the two center conductors of the NCPL to the balun input and the braid to the wire going to the center tap (as above).

Such a configuration will give some advantages over the “standard” NCPL one. The loop will now be galvanically isolated from the feedline/receiver so it will have much less “static noise.” Due to the tap, the typical 8 pattern of the loop will be preserved, this means that the loop will now have much deeper nulls.

By the way, the balun could just be wound w/o buying it. I suggested the nooelec since that way anyone with little soldering ability will be able to put it together. Oh and by the way it’s then possible adding a small preamp at the balun output if one really wants, any preamp accepting a coax input will work. 🙂

Again, if you can/want, give it a try !

Many thanks for sharing this, Grayhat! We always welcome your inexpensive, innovative urban antenna projects!

Post readers: If you have question, feel free to comment and I’m sure Grayhat can help. 

Pedro’s PL-310ET Pro Tip: Controlling ETM scans by changing bandwidth

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Many thanks to SWLing Post contributor, Pedro Andrade, who writes:

Hi Thomas!

I’m a noob when it comes to DXing, I only got into the hobby late 2020, and I got to say: I’m hooked. So, sooner or later, I would hit your website/blog. For that, and the continued work in every aspect of the hobby (technical issues, tips, tricks, schedules, etc), I thank you from a noob perspective and from someone that believes the internet is beautiful when it comes to sharing and getting communities together.

That said […]the reason for writing this email, is that I found out that the ETM scan could be very much improved on the Tecsun PL-310et (and I think others).

You simply change the filter sensitivity prior to the scan: the higher the filter the lower the sensitivity. The lower the filter (1 kHz) the higher the sensitivity and thus more stations caught by the scan.

Here’s a video showing it in action:

I hope you find this useful and worth sharing for your readers.

Thanks again for the continued work on the radio side of things.

Regards, Pedro.

What a brilliant tip, Pedro! Thank you for sharing and also for demonstrating in your video! Also, thank you for the kind words about the SWLing Post–an amazing community of folks like you and a pure labor of love!

C.Crane CC Skywave SSB: Jock adds a correction/addendum to his guest post about ATS tuning

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Many thanks to SWLing Post contributor, Jock Elliott (KB2GOM), who shares the following guest post:

I made a mistake, but it’s good news for CCrane Skywave SSB owners.

Recently, I published a guest post for the SWLing Post in which I wrote enthusiastically about the ATS feature on the CCrane Skywave SSB. Everything I wrote was true, except for one small detail. And that, it turns out, is a nice bonus for Skywave SSB owners.

We’ll get to that in just a moment, but first, let’s take a look at what the Skywave SSB manual says about memory:

“Memory Preset Buttons 0-9. Save your favorite stations to memory buttons. To save a station, press and hold any memory button for 2 seconds while the station is playing. To play a saved station, press the same button once quickly. Note: The CC Skywave SSB is a ‘smart’ radio and will remember current settings when a station is preset into memory. The current settings that will be saved with your stations are: 1. Stereo or Mono selection on FM. 2. Bandwidth selection on AM, Shortwave, or Air Bands. 3. Tone settings.”

Further, the manual says this about the Page Button:

“Each memory page allows you to save 10 additional stations per band. To change to a different page, press the PAGE button once quickly, then press any memory button 0-9 to select the Page you desire.”

So, do the math: there are 10 pages. Each page can store 10 memories. 10 x 10 = 100, right?

So imagine my surprise when I visited the C.Crane website early this AM, and the first thing that pops up is the Skywave SSB, and, prominently displayed, it says: “400 memories.”

Whaaaat?!

I check; the manual says nothing about 400 memories, no hint that by pressing some secret combination of buttons you can access memories beyond the 100 obvious ones.

Then it begins to dawn on me: what if each band – SW, AM, FM, AIR – has its own bank of 100 memories? That would account for C.Crane’s claim of 400 memories. Hmmm. Further, what if the ATS (Automatic Tuning System) function – which “programs all receivable stations in the AM, FM, Air and Shortwave bands to memory buttons” – automatically stores the frequencies in the appropriate memory bank for that band? That would be pretty neat.

So I grab the Skywave SSB and run a quick ATS search on the SW band. Sure enough, it stores some SW stations, starting at Page 1, Memory 1, overwriting whatever had been stored there. Then I select the AIR band and access memories, starting at Page 1, Memory 1. There are only AIR frequencies stored there. I select the FM band and access the memories; nothing but FM stations stored there. Same thing with AM. Clearly, there are separate memory banks for each band.

So here’s the good news: the Skywave SSB does, indeed, have 400 memories, a 100-memory bank for each band: SW, AM, FM, AIR. Further, when you do an ATS search, the frequency “hits” are stored, starting at page 1 for that band. Therefore, if you do an ATS search on the SW band, the hits are stored in the memories for SW, and the memories that are stored for, say, AIR, are not overwritten. (And that is where I got it wrong.)

So, if you are traveling, you can do a search on local AM stations, local FM stations, SW stations, and local AIR stations, each will be stored in its own memory bank, starting at page 1, memory 1, for that band. Pretty neat.

In addition, I need to offer a clarification. I wrote:

“if you put the Skywave SSB in single sideband mode, it will scan the ham bands, automatically changing sidebands appropriately as it hops from ham band to ham band. Note: when you check the memories stored during an ATS ham band search, you may not find anything there, simply because ham transmissions come and go much more often than international broadcasters.”

All of that is true, but the Skywave does not store whether the frequency is USB or LSB. My bad; I should have noticed that.

Cheers, Jock

Fukkatsu no hi: Emilio believes this post-apocalyptic Japanese film has a message

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Many thanks to SWLing Post contributor, Emilio, who writes:

Hi Thomas

I hope you are healthy. A few weeks ago, I got COVID-19; fortunately, I got the vaccine a few weeks ago, so my symptoms were minimal. Today only a little cough remains.

In my isolation, I listened to a lot shortwave radio and watch many old movies, including this one:

Fukkatsu no Hi–literally Day of Resurrection, also known as “Virus”–is a 1980 post-apocalyptic science fiction film about an advanced virus wiping out all life on Earth except 863 people in Antarctica. “

Below I’ll share a scene from the film–some mixed emotions about this scene as Japanese actors react.

Video Player

So this is why need teach to young and kids the basic radio communication, and perhaps handle of armament. Ha ha! 😀

Wow! This is great–thank you for sharing this, Emilio! I do hope you’re feeling better. I’m glad shortwave radio and post-apocalyptic Japanese films have given you refuge as your recuperate! I’ve gotten a number of messages recently from SWLing Post contributors out there who recently contracted a variant of Covid-19.

Readers, take some practical measures to avoid getting and spreading the virus, and stay healthy out there! We don’t want to lose any more of our radio community to this nasty bug. 

Be well and happy DX!

The SI-307: Another Si473X portable receiver

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Many thanks to SWLing Post contributor, Konrad, who writes:

Hello Thomas,

I was checking AliExpress in search of Hanrongda HRD 747 (still nothing yet) and accidentally I’ve found something which might be interesting.

For now there’s not much information about this device, but it seems that somebody produced a handheld equivalent of well known Si473X receivers.

Name is SI-307

https://aliexpress.com/item/1005003010068279.html

https://www.ebay.com/itm/184956500398

Currently there are no details, but they’re mentioning SSB support, which might suggest, that they’re using a well known Si4735-D60 or Si4732-A10 chip. Also it is unknown if device might be programmable as original (non-handheld) version of this receiver. Speaker seems to be built in.

Might be interesting to know, if anybody from The SWLing Post has decided to risk ~100 USD to check this out 🙂

PS: Thanks for your outstanding work, I’m checking The SWLing Post daily 🙂

Thank you, Konrad! Yes, I think you’re right in that this is simply another Si473X-based receiver.

Interesting: the aluminum alloy chassis almost seems to be snap-together. The connection tabs remind me of radio kits that use circuit board material at the chassis.

Also, the buttons and labels on the front faceplate seem so “homebrew.”

Like Konrad, I would be interested if anyone has tried this radio. I’m not sure I’d be ready to fork out money on it quite yet, although it is certainly an interesting take on the Si473X.

Thank you, again, Konrad!