Category Archives: How To

Radio Fun: Monitoring ISS Astronaut David Saint-Jacques as he answers student questions

My daughter hold the Kenwood TH-F6 HT while we listen to the ISS contact.

Many thanks to my good buddy Eric (WD8RIF) for reminding me about a scheduled ARISS (Amateur Radio on the International Space Station) contact between Canadian astronaut David Saint-Jacques and Faith Christian Academy in Orlando, FL, USA.

Astronaut David Saint-Jacques (Source: Canadian Space Agency)

Living in the mountains, I miss a lot of low angle ISS passes due to ridge lines blocking my line of sight. This time, though, the pass was high and mostly to my open south which meant it was one of the longest ARISS contacts I’m monitored.

My daughters drop everything to monitor radio or visual ISS passes–this February 14th pass was no exception.

In fact, I’m sure a lot of their enthusiasm about studying for their ham radio licenses stems from these ARISS events.

Of course, it doesn’t take an amateur radio license to monitor an ISS VHF transmission. I’ve used everything from handheld scanners to handheld ham radio transceivers. Click here to read a post with a short tutorial on monitoring ARISS contacts.

My daughters helped me make short videos of David Saint-Jacques’ replies (of course, we can’t hear the FL school’s transmissions). Below, I’ve matched the school’s questions with his answers:

Question regarding superstitions, traditions and rituals:

Click here to view on YouTube.

“Can you see any constellations while on the ISS and do you have a favorite one?”

Click here to view on YouTube.

“Have you ever experienced a major malfunction on the ISS?”

Click here to view on YouTube.

“Does everything in your body work the same in a microgravity environment, for instance, does your heart work harder to pump blood through the body?”

Click here to view on YouTube.

“Do your ears pop like they would when you fly in a plane?”

Click here to view on YouTube.

“Are you recognized as an astronaut on the streets?”

Click here to view on YouTube.

“Are you allowed to request certain things to be delivered by the cargo missions?”

Click here to view on YouTube.

“Describe the escape system on the ISS in case of an emergency.”

Click here to view on YouTube.

“How do you shave or cut your hair on the ISS without the hair floating away?”

Click here to view on YouTube.

“What experiment are you currently working on and is it going well?”

Click here to view on YouTube.

“What did you feel the first time you saw Earth from the ISS?”

Click here to view on YouTube.

Have you ever monitored an ARISS contact or grabbed one of the SSTV transmissions from the ISS? Please comment!

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Video: N1SPY brings a GE seven band radio back to life!

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Many thanks to SWLing Post contributor, Ivan Cholakov, who writes:

Thomas Cholakov (N1SPY) picked up an old General Electric radio from the 2019 Orlando Hamcation and brought it back to life. Unfortunately with all of the radio’s 7 bands, it did not have shortwave.

Click here to watch on YouTube.

Brilliant job resurrecting that GE portable, Tommy!!! Thank you for sharing.

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Ed restores a Hallicrafters S-72L cabinet

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Many thanks to SWLing Post contributor, Edward Ganshirt, who shares the following:

This is a Hallicrafters S-72L “barn find” I restored.

This turned out to be a furniture refinishing project and not a radio (electronics) restoration job.

It is a 1949/50 era portable with batteries and 1 volt tubes.

When I brought it home the cosmetic condition was such, I kept it away from the litter box out of an abundance of caution to prevent it from being buried by the cats.

This is a very early portable radio made out of plywood and coated with brown wall paper fabric imitating cheap portable record players and luggage of the era.

I decided to laminate it with cedar drawer liner to give it some class instead of vinyl wallpaper.

While learning to laminate wood is another skill outside the scope of this article, The trick when applying laminate is to prevent bubbles forming under the laminate.

Also all divits and dents should be filled in with Bondo or wood filler. The surface is lightly sanded with very fine sandpaper and at least 8 layers of gloss water based floor varnish applied and allowed to thoroughly dry before the next coat.

This radio has nice audio quality, It has a BFO and tunes the longwave band through 11MHz.

The only regrets is cleaning it aggressively which took away a lot of the “old radio smell”, but the cedar aroma will keep the moths out.

Fantastic, Ed! Thanks for sharing. I think you made a considerate upgrade to the S-72L. Great to hear this radio plays well and has excellent audio. I found one at a hamfest once in slightly better cosmetic condition, but much worse electrical condition than your pre-restoration unit. I’m sure I took a photo of it, but I can’t seem to find it in the archives.

Post readers: any other Hallicrafters S-72L owners out there? Have you ever installed wood laminate on a radio cabinet? Please comment!

Do you enjoy the SWLing Post?

Please consider supporting us via Patreon or our Coffee Fund!

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“Crystals Go To War”: A 1943 film about the production of Signal Corps radio crystals

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Many thanks to SWLing Post contributor, Charlie (W4MEC), who shares this fascinating film which documents the production and calibration of crystals in 1943. I had no idea of the amount of labor and attention to detail this process required–an absolutely fascinating process:

UPDATE (08/09/2022): the YouTube account associated with this film has been deleted by the owner.

Click here to view this same film now hosted by the Antique Wireless Association.

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An external battery pack for the Sony ICF-SW35?

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

Hi Thomas I enjoy reading your blog and often when I put a question in Google yours is the first on the list so I wonder if you’d mind if I ask you a question about the Sony SW35.

I’m interested to try powering it from a power bank but I have no idea what DC plug to buy for it as I bought it second-hand without an adaptor.

I thought about taking a couple of wires out of the battery compartment but it wouldn’t look as nice so any help you could give me would be much appreciated.

Great question, Adam!

You can certainly find a DC plug that will work with the ICF-SW35. I believe this same plug was used with a number of Sony Walkman type players back in the day. You might be able to find one at the local charity/thrift shop in their power cord jumble.

I do know that the coaxial type plug needs to have positive tip polarity (click here to read about this in the owner’s manual) and the radio requires 4.5 VDC . The OEM power adapter (Model AC-E45HG) provided 700 mAh, but I don’t know what the ‘SW35 actually requires (other than something equal to or less than 700 mAh).

One option would be to find a 12VDC to 4.5 VDC converter like the Sony DCC-E345 and plug it into a 12VDC source (there are a number of high capacity 12V battery packs on the market).

Of course, you could also build your own external source by purchasing an appropriately sized external battery holder. I would use a D cell holder (I assume one to hold 3 cells at 1.5VDC x 3 = 4.5 VDC) which would provide much better capacity than a AA cell holder. (Something like this.)

I haven’t been able to determine the +/- voltage tolerance of the ICF-SW35, so I would keep the supply voltage figure at or below 4.5 volts.

One crucial number I’m missing is the coaxial plug size. I can’t seem to find a spec for OEM Sony AC-E45HG. I hope a reader might be able to help us here.

Post readers: Can anyone confirm the DC plug size for the Sony ICF-SW35? If you have any other advice or tips for Adam, please comment!

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Robert talks uBITX and navigating the world of used radio gear

Stefano invites you to experiment with DRM (Digital Radio Mondiale) over IP

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Many thanks to SWLing Post contributor, Stefano Mollo (VK6WFM), who writes:

I have been lately experimenting with DRM 30, with the aim of coming up with a cheap solution to get on air for next to no $$$, for small, local broadcasters that would either go pirate on FM or would not go at all due to the impossibility here in Australia to get a proper FM license at a cost that does not involves selling a kidney (or two)!

I am a ham radio operator, so I turned my attention to DRM30; [the DRM application] DReaM has the capability of acting as a transmitter as well, so I started experimenting.

Click here to download DReaM via SourceForge.

I was very successful at transmitting a DRM30 / 10 kHz signal with a $ 0.50 TX module otherwise intended to transmit data with an Arduino. The signal was received with an SDR + HDSDR + Virtual Audio Cable + DReaM in reception mode.

So far, so good; with this experiment I realised that DRM 30 can, in fact, yield excellent quality at ANY frequency (as I used the 433Mhz LIPD range in my experiment) or better said, with any medium, as long as it is linear enough to transport the DRM signal.

I wanted to find a way to show the World – literally – what can be achieved with DReaM in TX mode…for free!!!

So, after some trial and error, I have set up the system below which allows anyone in the World to “tune in” my “DRM30 radio station” and listen to my DRM30/18 kHz signal, in full blown stereo. Quality is exceptional, and just imagine to send DReaM’s signal to a proper transmitter instead of streaming it over the internet ….

So…point your VLC Media Player (on Windows) to stream from:

…then pipe VLC’s output to DReaM’s input via Audio Cable (or any other Virtual Audio Cable you like).

In DReaM, select the audio cable output as the sound card’s signal input device:

Then select L+R as Channel:

Set the sample rate to the highest value:

One more thing you need to set is the “Channel Estimation: Time Interpolation” parameter to Linear; this is very important!

After few seconds you should be able my test signal, in full stereo, streamed from a PC running DReaM in TX mode, whose output is then captured by MB Recaster and streamed to an ICE Cast server I have in the Cloud. Note that no particular configuration was needed on the ICE Cast server, at all.

This is an example of what can be achieved on a solid transmission channel with DRM30 and only 18 kHz bandwidth (i.e. the normal bandwidth of an AM channel).

One can achieve the same exact audio quality using any channel linear enough to transport an 18 kHz wide DRM30 signal. It doesn’t matter the frequency, or the physical medium per se.

[…]My aim with this experiment is not to send DRM over IP; there are much simpler ways or streaming audio over IP.

Rather, my aim is to demonstrate what can be achieved with 18 kHz +DRM30 on any frequency and on any medium (which, could be for example the electrical distribution overhead lines …. just saying …. 🙂 ).

If only the local regulator would support this, instead of enforcing draconian regulations … such as the restriction of just 6 kHz on shortwave.

Please share your thoughts.

Fascinating experiment, Stefano! Thanks for sharing!

Post readers: If you’re in the mood to do a little experiment, let us know if you’re able to decode Stefano’s 18 kHz DRM30 broadcast over IP! Please comment!

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