KPH Article on TechCrunch and Bay Area Backroads

Cypress tree avenue towards KPH. Photo by Frank Schulenburg via Wikimedia Commons

Many thanks to SWLing Post contributor, Dan Van Hoy, who writes:

“The Last Radio Station,” an article about maritime radio station, KPH, is up on TechCrunch ( https://techcrunch.com/2020/01/18/the-last-radio-station/ ).

KPH is silent on maritime frequencies, but through the hard work of volunteers continues operation 24/7 with a 3-30MHz KiwiSDR receiver (http://198.40.45.23:8073/) and various activities throughout the year. Full information on all things KPH can be found the excellent Maritime Radio Historical Society Website (http://www.radiomarine.org/).

Finally an excellent “Bay Area Backroads” episode about KPH is available on Youtube:

Can you copy the CW message at the end of the show?

Please comment if you can copy the CW message!

Thanks to much for sharing this, Dan!

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MULTIPSK Update

Patrick Lindecker, author of MULTIPSK, has announced an update to the software with the addition of DMR decoding (not to be confused with DRM, the subject of several recent posts – alphabet soup!!).

Here is a portion of the announcement:

New release of MULTIPSK (4.42)

The new release of MultiPSK (4.42) is on my Web site (http://f6cte.free.fr/index_anglais.htm).
The mirror site is Earl’s, N8KBR: https://www.paazig.net/f6cte/MULTIPSK_setup.exe

The main improvement of MULTIPSK 4.42 is the following:
Ham DMR decoding (but not the voice)

“DMR” is the acronym for “Digital Mobile Radio”. The basic specifications of this mode are public (ETSI TS 102 361-1 to 3 for the “Tier II” protocol used by Hams), but any supplier can add supplementary functions. It is used in VHF and in UHF, mainly for voice communication but also for data communication. It is a mode for professionals but also used by amateurs (according to a precise organization). For Hams, it is spread in a world net by using, among other means, repeaters and Internet.

The amateur DMR communications are the sole object of the Multipsk decoding (professional communications are decoded but ignored). The DMR is considered as a “professional” mode by Multipsk (but the Ham decoding is not limited in time).

It is here only considered the data communication which summarizes to identifiers (callsigns+first names) and possible text messages (with some rare positions).

Example:

F9XYZ Michel (2088006 – France), via TG 20800 (YSF France) – Slot 1

F0ZZZ Yves (2083004 – France), via TG 20800 (YSF France) – Slot 1

Note: the voice communication decoding is excluded because it needs an AMBE+2 Codec (under a proprietary licence).

For Hams and SWL, the DMR signal can be received:

· either from the discriminator output of a classical VHF/UHF FM receiver via a direct connection to the PC sound card. However, the receiver must have a large reception bandwidth due to the high modulation speed,

· or with a SdR receiver (FunCube Dongle, RTL SDR,…) and directly demodulated by Multipsk. It is the simplest solution.

Here is the WEB address where you can know where all DMR repeaters are located, with their frequencies, for each country: https://www.repeaterbook.com/repeaters/niche/index.php?mode=DMR

This mode is in freeware, so without time limitation.

MULTIPSK comes in two versions – a freeware version and a one-time paid version. It’s the same download, but buying a serial number unlocks many additional features. Note however, the DMR function is part of the free program.

While there have been many additional updates to the software from the time I wrote a review of the program, if interested you can access my review (published in The Spectrum Monitor) here:

MULTIPSK Review

Cheers! Robert K4PKM

Robert Gulley, K4PKM (formerly AK3Q), is the author of this post and a regular contributor to the SWLing Post.       Robert also blogs at All Things Radio.

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DRM30 on a Smartphone: KTWR Shows Us The Way

Image via the KTWR Blog

Many thanks to SWLing Post contributor, Dan Van Hoy, who writes:

[Regarding the reception of DRM via smart phone,] I happened to find this KTWR Guam post about decoding DRM30 with a smart phone, app, and an RTL-SDR:

Convert Smart Phone to DRM 30 HF receiver!

We are pleased to report successful use of an SDR Dongle used to directly receive and Decode DRM 30 over HF today.

The SDR Dongle is an RTLSDR v3 type connected to an android smartphone using an OTG cable (phone or tablet must be OTG capable).

The Software used:
1. Android driver (free)
2. DRM+SDR Android App ($4.99)

The Frequency of the HF broadcast is directly assigned within the DRM+ SDR app with two settings
1. Frequency in Hertz
2. RF Gain (0-512)

Demonstration video showing Clean DRM decode of AAC Audio and Journaline data along with live metadata.  (our signal was very strong, so only a short wire used for Antenna, DX’rs will need an appropriate Antenna)

Now anyone with a smartphone and a $20 SDR can receive DRM 30 HF broadcasts…

Click here to read this post on the KTWR blog.

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2020 Radio Prague QSL Cards

Many thanks to SWLing Post contributor, David Iurescia (LW4DAF), who writes:

“These are the new 2020 QSL Cards from Radio Prague International.
The theme of this year is “Transmitters” (Antennas):”

(Source: Radio Prague)

The three letters – QSL – constitute one of the codes originally developed in the days of the telegraph. All codes consisted of three letters beginning with “Q”. Later some of these “Q” codes were adopted by radio-telegraphists and radio listeners. QSL means “contact confirmed” or “reception confirmed”.

The expression “QSL card” or just “QSL” gradually came to be used among radio-amateurs and then more broadly as radio began to develop as a mass medium. Radio stations were keen to know how well and how far away their programmes could be heard and began to send their listeners “QSL cards” in return for reception reports. The card would include letters making up the “call sign” of the station – the system still used in the United States – or the broadcasting company’s logo or some other illustration. The card would also include a text stating the frequency and the transmitter output power, and a confirmation of when the listener heard the station.

Domestic broadcasters do not tend to use QSL cards these days, but their popularity remains among radio stations broadcasting internationally. They are still keen to know how well they can be heard in the parts of the world to which they broadcast. In the era of shortwave broadcasts Radio Prague sent out QSL cards for reception reports received. After curtailing our shortwave transmissions as of February 1, 2011 we will continue issuing QSL cards for reception via the Internet.

Here you can look through our current and past series of QSL cards:

Click here to view all of the new QSL cards from Radio Prague.

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External FM antenna for Android phones/tablets

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

Check this little gadget for android phones or tablets

https://www.aliexpress.com/item/32976847250.html

If they have the FM app installed than this will come handy.

One needs to select speaker and not earphone as expected.

It works fine here. (I don’t know if Apple phones have an FM module)

Thank you, Adid! Very cool! This little antenna costs $0.90 USD–an insanely low price.

If you have an old set of earphones lying around the house (I probably have two dozen that ship with various radios) you could also snip off the earpieces and use the pigtail as a wire FM antenna.

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Ham CAP and VOA Prop: Fixing SSN look-up files

VOA Prop

Many thanks to SWLing Post contributor, Paul Evans, who notes:

Users of these two propagation prediction programs will find that they don’t work beyond Dec 2019 because the SSN look-up files didn’t go any further.

I noticed this 2-3 years ago and added to the end of the files required. I entered guesses for solar activity values, but with auto mode turned on they will fetch current values. At least this will get you started again. Or my guesses might be right!! 🙂

For Ham CAP use: http://w4.vp9kf.com/SSN.dat

For VOAProp use: http://w4.vp9kf.com/ssndata.txt

Download them and swap them into the directory where the application is located.

Thanks or the help, Paul!

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An app to decode DRM?

DRM broadcast (left) as seen via a KiwiSDR spectrum display.

Many thanks to SWLing Post contributor, Richard Langley, who shares this story by Hans Johnson at Radio World:

Can an App Solve the DRM Receiver Problem? (Radio World)

The Digital Radio Mondiale standard for digital broadcasting in long, medium, and shortwave bands offers the possibility to transmit audio, text and pictures.

A few broadcasters use DRM for both domestic and international transmissions. DRM’s largest problem is lack of receivers, especially affordable standalone ones.

Some listeners use an SDR, computer and free Dream software to receive the DRM signals, but this audience doesn’t make up the mass audience that broadcasters are looking for.

[…]AlgorKorea didn’t develop the apps with the intention of solving the DRM receiver issue. They developed them to resolve a problem with FM hearing aids used in classrooms.

So how do they work? The DRM+SDR version couples the popular and inexpensive RTL-SDR to an Android device with a USB OTG adapter.[…]

Click here to read the full article at Radio World.

 

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