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Hobby Public Radio

Your ideas, projects, opinions - podcasted.

New episodes Monday through Friday.

Welcome to HPR the Community Podcast

We started producing shows as Today with a Techie on 2005-09-19, 16 years, 4 months, 8 days ago. Our shows are produced by listeners like you and can be on any topic that "are of interest to hobbyists". If you listen to HPR then please consider contributing one show a year. If you record your show now it could be released in 12 days.

Meet the team

Please help out tagging older shows !

Latest Shows

hpr3515 :: ADB and scrcpy

Some useful tools for working with Android Devices

Hosted by Ken Fallon on 2022-01-21 is flagged as Clean and released under a CC-BY-SA license.
Tags: adb,scrcpy,android Debug Bridge.
Listen in ogg, spx, or mp3 format. Comments (0)

Android Debugging

Install ADB Tools

There are multiple guides online as to how to install, but I found dnf install android-tools.x86_64 adb-enhanced.noarch the easiest. Similar commands are available for the other distros. Use your package manager to search for adb.

Enable Developer options

Go to Settings. Usually via the pulldown menu from the top twice, and click the cog icon. Search for 'Build Number', it's usually in Click on 'About Phone' Click on 'Build Number' seven times.

Go back and then search for 'Developer options' it's usually in the System section

You'll need to turn on two features 'Android Debugging' and 'ADB over network'

While we are at it, go back and then search for 'IP Address' it's usually in the About phone section. You should see a IPv4 address eg: Make note of the IP address as we'll use it later.

Using ADB

To get help use the command adb help

  • global options: Tell you how to connect to the phone
  • general commands: Shows your devices, and gives help
  • networking: Allows you to connect over the network but also to port forward and reverse traffic
  • file transfer: The only reliable way to get files to and from your device.
  • internal debugging: Shows how to control the server


Plug your phone using a usb cable. There will be a notification and a popup to allow the connection.

Run adb shell and all going well you should see your phone. Commands like ls, cd, and find work well. For example find /storage/self/primary/.


Unfortunately if you unplug your phone you no longer have a connection to it, but you can enable network access via tcp. Leave your phone connected to USB and then tell it to use a TCP/IP connection with the command adb tcpip 5555.

Then connect to the phone using the phones IP address and port 5555, adb connect It should reply with a connected to message

$ adb connect
connected to

Now commands like adb shell should allow you to access the phone even if it's not physically connected via usb.

Multiple devices

Got multiple devices then you can connect them all in the same way as shown above. The only issue is you need to tell adb which one you want to address.

The first thing you need to do is list the devices

$ adb devices -l
List of devices attached   device product:XXXX model:XXXX device:XXXX transport_id:9   device product:YYYY:ZZZZ device:ZZZZ transport_id:14

The important bit is the transport_id at the end. You can then use the adb command as normal but specifying the -t option

-t: allocate a pty if on a tty (-tt: force pty allocation)

So for example adb -t 14 shell would connect to phone YYYY

So that's it for remote control from the shell, but what if you want to see and interact with the screen itself ?

Remote screen sharing with scrcpy

From Wikipedia

scrcpy is a free and open-source screen mirroring application that allows control of an Android device from a Windows, macOS, or Linux desktop computer. The software is currently developed by Genymobile, which also developed Genymotion, an Android emulator.

The source code is available on github. It's available via apt install scrcpy on Ubuntu. In Fedora you'll need to enable it from the copr repo.

dnf copr enable zeno/scrcpy
dnf install scrcpy

With only one phone connected you can just type scrcpy and the screen will appear. Remember right click is power, and the mouse is your finger ;-).

If you have multiple devices connected you can connect using scrcpy --tcpip=

scrcpy is a wonderful tool that deserves a show in itself, but in short it lets you interact with your phone as if it was a VNC/Remote Desktop session. You can copy text from the phone as well.

It allows for control of the screen, as well as screen recording.

hpr3513 :: HB9HNT and PA7KEN on SOTA, Summits on the Air

Summits on the Air is the combination of mountain climbing and amateur radio

Hosted by beni on 2022-01-19 is flagged as Explicit and released under a CC-BY-SA license.
Tags: ham, ham radio, hamradio, sota.
Listen in ogg, spx, or mp3 format. Comments (0)

You'll find further information under the following links:

hpr3512 :: Auld Acquaintance

flappin gums aboot auld hardware and how I use it.

Hosted by Jezra on 2022-01-18 is flagged as Clean and released under a CC-BY-SA license.
Tags: auld hardware, photography.
Listen in ogg, spx, or mp3 format. Comments (0)

Toshiba Satellite L455-S5000

The script!


# target dir is ~/Photos/YYYY-MM-DD_Hm
targetDir="/home/$USER/Photos/$(date +"%F_%H%M")"

# create the dir
mkdir $targetDir

# cd to dir
cd $targetDir

# kill all gphoto stuff
pkill -f gphoto2

# get the files
gphoto2 --get-all-files

# delete all files on camera recursively
gphoto2 -DR

hpr3511 :: Podman like Vagrant

This is how I use Podman on the desktop

Hosted by klaatu on 2022-01-17 is flagged as Clean and released under a CC-BY-SA license.
Tags: containers, podman, docker, vagrant.
Listen in ogg, spx, or mp3 format. Series: Virtualization | Comments (0)

I used to use Vagrant to spin up minimal virtual machines when I needed to test code on a different distro than what I ran. Lately I've switched to Podman.

Install Podman with your distribution's package manager.

Configure it:

$ sudo --add-subuids 200000-265536 \
--add-subgids 200000-265536 \

Create a directory to share data between your container and your localhost:

$ mkdir data

Run a container, with your ./data directory mapped to /storage in the container:

$ podman run -it --volume ./data:/storage:Z busybox

hpr3510 :: Syntax, Switches, and Help

We continue our look the old warhorse, DOS. This time it is Syntax, Switches, and Help.

Hosted by Ahuka on 2022-01-14 is flagged as Clean and released under a CC-BY-SA license.
Tags: DOS, early PC computing, syntax, switches, help.
Listen in ogg, spx, or mp3 format. Series: DOS | Comments (1)

Since DOS is a command line type of operating system, it is really important that you understand the syntax of commands. The good news is that the system will do what you tell it to do. But the bad news is that it will do what you tell it to do. You have to tell it in the precisely correct way, and that means Syntax. And with a number of commands you can modify them using Switches. And where do you learn all about Syntax and Switches? Why, in the HELP system, of course!

hpr3509 :: Linux Inlaws S01E46: The Matrix Project (Without Neo)

The Matrix Project Without Neo

Hosted by monochromec on 2022-01-13 is flagged as Explicit and released under a CC-BY-SA license.
Tags: Matrix, Element, federated social network, peer-to-peer communication.
Listen in ogg, spx, or mp3 format. Series: Linux Inlaws | Comments (0)

In this episode, the Inlaws are hosting Neil Johnson, VP of Engineering at Element. But this is not just about this popular Matrix graphical user interface but rather about this federated communication network dubbed as the next big thing after Mastodon and Discord, soon to take over the world (pretty much like the Inlaws themselves - it's gonna get crowded... :-).


hpr3508 :: Differences between C# and Haskell

tuturto talks about some of the differences between C# and Haskell

Hosted by tuturto on 2022-01-12 is flagged as Clean and released under a CC-BY-SA license.
Tags: haskell, c#, programming.
Listen in ogg, spx, or mp3 format. Series: Haskell | Comments (0)

This episode covers some of the differences between C# and Haskell. I'm probably going to omit lot of things accidentally.

  • Origin: practical language for solving real world problems vs. programming language research
  • Main paradigm: object oriented vs purely functional
  • Changing data: mutability vs. immutability
  • Data structures: inheritance vs. composition
  • Execution model: strict vs. nonstrict
  • Side effects: anywhere vs. specifically marked areas in the code

Thanks for listening, if you have any questions or comments, you can reach me via email or in fediverse, where I'm Or even better, you could record your own hobby public radio episode.

hpr3507 :: USB Turntable fix and sound journey

USB Turntable fix and sound journey with arecord, asound and ffmpeg

Hosted by Archer72 on 2022-01-11 is flagged as Clean and released under a CC-BY-SA license.
Tags: Vinyl, album, Vinyl album, record album, aplay, arecord, alsaloop, ffmpeg,retro, USB turntable.
Listen in ogg, spx, or mp3 format. Comments (0)

Partial list of albums

  • Journey - Frontiers
  • Journey - Evolution
  • Journey - Greatest Hits
  • Journey - Departure
  • Chicago - 2 albums - unknown titles
  • John Denver - Rocky Mountain Christmas
  • Inside Star Trek (1976)
    • SIDE I Inside Star Trek Star Trek Theme William Shatner Meets Captain Kirk The Origin of Spock Sarek's Son Spock The Questor Affair
    • SIDE II The Enterprise Runs Aground McCoy's Rx for Life The Star Trek Philosophy Asimov's World of Science Fiction A Letter From a Network Censor The Star Trek Dream Ballad I/Ballad II)*

Inside Star Trek album: Cover
Inside Star Trek album: Cover
Click the thumbnail to see the full-sized image - -

Inside Star Trek album: Contents
Inside Star Trek album: Contents
Click the thumbnail to see the full-sized image - -

I found a turntable at the thrift store, and the spindle ran, but the platter did not. The belt had slipped off, and here is the fix.

How to remove platter
How to remove platter
Click the thumbnail to see the full-sized image - -

Belt placement
Belt placement
Click the thumbnail to see the full-sized image - -

Routing Audio from a USB Turntable to HDMI using a Raspberry Pi

Send input to output

alsaloop -t 500000 -C hw:CARD=CODEC,DEV=0 -P default:CARD=b1

alsaloop man page

Parameter b1 is found by

pi@retropie:~ $ aplay -l
**** List of PLAYBACK Hardware Devices ****
card 0: b1 [bcm2835 HDMI 1], device 0: bcm2835 HDMI 1 [bcm2835 HDMI 1]

Raspberry Pi as a USB audio capture device

Used hw:CARD=CODEC,DEV=0 derived from 'arecord -L'

USB Audio CODEC, USB Audio
Direct hardware device without any conversions

arecord man page

   -D, --device=NAME
    Select PCM by name
    -V, --vumeter=TYPE
    Specifies the VU-meter type, either stereo or mono. The stereo VU-meter is available only for 2-channel stereo samples with interleaved format.
    -c, --channels=#
    The number of channels. The default is one channel. Valid values are 1 through 32.
    -f --format=FORMAT
    Sample format
    Recognized sample formats are: S8 U8 S16_LE S16_BE U16_LE U16_BE S24_LE S24_BE U24_LE U24_BE S32_LE S32_BE U32_LE U32_BE FLOAT_LE FLOAT_BE FLOAT64_LE FLOAT64_BE IEC958_SUBFRAME_LE IEC958_SUBFRAME_BE MU_LAW A_LAW IMA_ADPCM MPEG GSM SPECIAL S24_3LE S24_3BE U24_3LE U24_3BE S20_3LE S20_3BE U20_3LE U20_3BE S18_3LE S18_3BE U18_3LE
    Some of these may not be available on selected hardware
    The available format shortcuts are:

    -f cd (16 bit little endian, 44100, stereo) [-f S16_LE -c2 -r44100]
    -f cdr (16 bit big endian, 44100, stereo) [-f S16_BE -c2 -f44100]
    -f dat (16 bit little endian, 48000, stereo) [-f S16_LE -c2 -r48000]

Recording to FLAC

How can one record mic audio straight to a FLAC file?

ffmpeg -f alsa -ar 48000 -ac 1 -i hw:0 testfile.flac

Took out the "-ac 1", which downmixed the input to mono

Change hw:0 to hw:2 based on

pi@retropie:~/vinyl $ arecord -l
**** List of CAPTURE Hardware Devices ****
card 2: USB20 [AV TO USB2.0], device 0: USB Audio [USB Audio]
Subdevices: 1/1
Subdevice #0: subdevice #0

ffmpeg -f alsa -ar 48000 -i hw:2 testfile_stereo.flac

FFmpeg Audio Channel Manipulation

Previous five weeks

hpr3505 :: A DX with Hotel Bravo 9 Hotel November Tango hosted by beni

Released: 2022-01-07. Duration: 00:48:10. Flag: Clean. Series: HAM radio.
Tags: Swiss,BAKOM,HamRadioTrainer,HB9.
Ken (PA7KEN) and Beni (HB9HNT) talk about getting your HAM ticket in Switzerland

hpr3504 :: James Webb Space Telescope hosted by Dave Morriss

Released: 2022-01-06. Duration: 00:45:18. Flag: Explicit.
Tags: astronomy,telescope,rocket launch,JWST,NASA,ESA,CSA.
Andrew and Dave watch the launch of the JWST

hpr3503 :: Configuring Mumble hosted by Ken Fallon

Released: 2022-01-05. Duration: 00:15:06. Flag: Clean.
Tags: mumble,hpr mumble, new year show.
In this episode we will show you how to connect to the HPR Community Room on Mumble.

hpr3502 :: New year Greetings and a short review of my new Juno PC hosted by Tony Hughes AKA TonyH1212

Released: 2022-01-04. Duration: 00:04:51. Flag: Clean.
Tags: Ubuntu, Linux Mint, Juno computers, Ryzen 5900, New Year Greetings.
I just ramble for a few minutes about my new Juno PC

hpr3501 :: HPR Community News for December 2021 hosted by HPR Volunteers

Released: 2022-01-03. Duration: 01:12:04. Flag: Explicit. Series: HPR Community News.
Tags: Community News.
HPR Volunteers talk about shows released and comments posted in December 2021

hpr3500 :: Contrast Layer Modes hosted by Ahuka

Released: 2021-12-31. Duration: 00:16:59. Flag: Clean. Series: GIMP.
Tags: GIMP, Layer Modes, Blending Modes, Contrast Modes.
More on Layer Modes in GIMP with the Contrast Modes

hpr3499 :: Fixing a noisy blower motor hosted by Archer72

Released: 2021-12-30. Duration: 00:04:24. Flag: Clean.
Tags: car,repair,maintenance,bearing.
I fix a noisy blower motor that I put off since last winter.

hpr3498 :: Linux Inlaws S01E45: The Big Xmas New Year bash with the Grumpies hosted by monochromec

Released: 2021-12-29. Duration: 02:14:36. Flag: Explicit.
Tags: Mainframes, IBM, Hyperscaler secrets, Rust, old men, programming languages.
the same as the title so I'm not going to repeat it

hpr3497 :: Jankilators. hosted by one_of_spoons

Released: 2021-12-28. Duration: 00:21:15. Flag: Explicit.
Tags: oscillators,complexity,flux,alternator,3phase,field,trees,sky.
Follow the wail of the janky scissor monster into the muddy flux of headtorch borderlands.

hpr3496 :: How I record HPR Episodes hosted by norrist

Released: 2021-12-27. Duration: 00:28:27. Flag: Clean.
Tags: python,sox.
Some python to record short segments of audio.

hpr3495 :: Podcast Recommendation: The Retroist hosted by Archer72

Released: 2021-12-24. Duration: 00:01:32. Flag: Clean. Series: Podcast recommendations.
Tags: retro,retroist,nostalgia,1988,die hard,bruce willis,podcast.
Podcast Recommendation: The Retroist number 243 - Die Hard

hpr3494 :: Recent Generator Repairs and Maintenance hosted by Jon Kulp

Released: 2021-12-23. Duration: 00:18:00. Flag: Clean.
Tags: Engine repair, generators, electricity, emergency preparedness.
I talk about my Generac 4000XL gasoline-powered generator and what I've done to get it running right

hpr3493 :: My First Spanish HPR Episode hosted by Claudio Miranda

Released: 2021-12-22. Duration: 00:05:02. Flag: Clean.
Tags: spanish,languages,castellano,espanol,pubnix,textoplano,podcast.
A short Spanish episode inspired by discussions about non-English episodes on the HPR mailing list.

hpr3492 :: Linux Inlaws S01E44: Pipewire Just another audio server Think again hosted by monochromec

Released: 2021-12-21. Duration: 00:52:50. Flag: Explicit. Series: Linux Inlaws.
Tags: Linux audio, Pipewire, PulseAudio, Jack, gstreamer, Rubik's Cube, Kefir.
Pipewire - Just another audio server? - Think again!

hpr3491 :: My Github and flickmetrix hosted by operat0r

Released: 2021-12-20. Duration: 00:25:53. Flag: Explicit.
Tags: scripts,hacking,github,windows,linux.
Bear with me as I go though my github over the past year some real gems in here

hpr3490 :: The Path hosted by Ahuka

Released: 2021-12-17. Duration: 00:15:06. Flag: Clean. Series: DOS.
Tags: DOS, early PC computing, The Path.
More on DOS. This time it is the Path.

hpr3489 :: Equality of structured errors hosted by tuturto

Released: 2021-12-16. Duration: 00:12:56. Flag: Explicit. Series: Haskell.
Tags: haskell, eq.
tuturto talks about equality in Haskell

hpr3488 :: Binaural 3d audio recording, please listen at normal speed with good head phones. hosted by Quvmoh

Released: 2021-12-15. Duration: 00:05:02. Flag: Clean. Series: Sound Scapes.
Tags: Binaural, storm, thunder.
recorded November 19 2021 quick storm.

hpr3487 :: Installing a cat door hosted by Rho`n

Released: 2021-12-14. Duration: 00:24:06. Flag: Clean.
Tags: Install, cat door.
Rho`n installs a cat door in his interior basement door

hpr3486 :: Unleash the true potential of GNU nano text editor hosted by hakerdefo

Released: 2021-12-13. Duration: 00:08:36. Flag: Explicit. Series: Lightweight Apps.
Tags: text-editor, terminal, linux, nano, pico, pine, nanorc.
Turn GNU nano text editor into a fancy, good looking & powerful editor

hpr3485 :: 50 years since the 1st Edition of Unix was published hosted by Ken Fallon

Released: 2021-12-10. Duration: 00:12:27. Flag: Explicit.
Tags: unix, unix commands.
Ken (Fallon not Thompson) checks his unix like computer to see how many commands still exist.

hpr3484 :: My vim setup with GnuPG hosted by Archer72

Released: 2021-12-09. Duration: 00:08:21. Flag: Clean. Series: Lightweight Apps.
Tags: vim, plugin, lightweight.
My vim setup with the GnuPG vim plugin

hpr3483 :: Pinephone64 review hosted by sigflup

Released: 2021-12-08. Duration: 00:09:23. Flag: Clean.
Tags: linux,cellphone,pinephone,mobie phone.
Sigflup got a pinephone and wants to talk about it.

hpr3482 :: Introduction to Post Apocalyptic Robotics Meta Technology hosted by Mechatroniac

Released: 2021-12-07. Duration: 00:13:30. Flag: Explicit.
Tags: beam,righttorepair,robots,mechatronics.
Building robots from junk parts and tech prepping

hpr3481 :: HPR Community News for November 2021 hosted by HPR Volunteers

Released: 2021-12-06. Duration: 01:33:58. Flag: Explicit. Series: HPR Community News.
Tags: Community News.
HPR Volunteers talk about shows released and comments posted in November 2021

hpr3480 :: Darken Layer Modes hosted by Ahuka

Released: 2021-12-03. Duration: 00:14:43. Flag: Clean. Series: GIMP.
Tags: GIMP, Layer Modes, Blending Modes, Darken Modes.
More on Layer Modes in GIMP with the Darken Modes

hpr3479 :: Linux Inlaws S01E49: Version Control Systems and why bother hosted by monochromec

Released: 2021-12-02. Duration: 00:56:54. Flag: Explicit. Series: Linux Inlaws.
Tags: Version control systems, git, subversion, mercurial, bazaar, how to buy guns as a minor in NL.
Version Control Systems and why bother

hpr3478 :: Audio Wiring Hack on a Classroom Podium hosted by Jon Kulp

Released: 2021-12-01. Duration: 00:18:13. Flag: Clean.
Tags: audio, wiring, higher education.
Listen in while I hack the wiring on our classroom podium for custom audio routing.

hpr3477 :: Picking a Forth hosted by Brian in Ohio

Released: 2021-11-30. Duration: 00:21:53. Flag: Clean.
Tags: forth, arduino, history.
Available forths, old and new

hpr3476 :: My mutt email setup hosted by Archer72

Released: 2021-11-29. Duration: 00:12:45. Flag: Clean. Series: Lightweight Apps.
Tags: mutt,email, gpg,accessibility .
My humble mutt email setup

hpr3475 :: How I Watch Everything Using Open Source Software hosted by minnix

Released: 2021-11-26. Duration: 00:14:38. Flag: Clean.
Tags: libreelec,kodi,raspberry pi,tvheadend.
Using Libreelec, Kodi, a tuner, and a Raspberry Pi to create a great media center

hpr3474 :: H P R and Audio Fun hosted by operat0r

Released: 2021-11-25. Duration: 00:11:11. Flag: Explicit.
Tags: audio.
Comments on show and audio processing

hpr3473 :: My journey into Amateur Radio hosted by thelovebug

Released: 2021-11-24. Duration: 00:10:16. Flag: Clean. Series: HAM radio.
Tags: amateur radio, baofeng, rsgb, qso, cq, ham, ham radio, hf.
Dave explains his journey into Amateur Radio, initial setup and successes.

hpr3472 :: consuming an AQI API hosted by Jezra

Released: 2021-11-23. Duration: 00:06:26. Flag: Clean. Series: Programming 101.
Tags: ruby, api, programming.
just because the sky is clear, doesn't mean the air is safe to breathe

hpr3471 :: The Sony Walkman WM-F41 hosted by Jon Kulp

Released: 2021-11-22. Duration: 00:08:51. Flag: Clean.
Tags: audio, vintage audio, cassette tapes, tape players, portable stereos, audio repair.
A quick talk about one of my favorite Legacy Audio devices, a genuine Sony FM/AM cassette Walkman.

hpr3470 :: External Commands and Emergency Boot Disk hosted by Ahuka

Released: 2021-11-19. Duration: 00:16:48. Flag: Clean. Series: DOS.
Tags: DOS, early PC computing, External Commands, Emergency Boot Disk.
More on DOS. This time it is External Commands and Emergency Boot Disk

hpr3469 :: Linux Inlaws S01E43: The Great Battle or not hosted by monochromec

Released: 2021-11-18. Duration: 01:08:58. Flag: Explicit. Series: Linux Inlaws.
Tags: SQL, NoSQL, Grumpy Old Coders, Hipster databases, mainframes, Execution planners.
The Great Battle nor Not

hpr3468 :: Distro upgrade intervals on my Raspberry Pi hosted by MrX

Released: 2021-11-17. Duration: 00:13:06. Flag: Explicit.
Tags: Linux, Distros, Raspberry Pi, Debian.
In this episode I discuss Debian distro upgrade intervals for my raspberry Pi

hpr3467 :: Protonmail in the terminal hosted by dnt

Released: 2021-11-16. Duration: 00:37:42. Flag: Explicit.
Tags: email,protonmail,alot,afew,notmuch,mbsync.
One way of doing Protonmail in the terminal.

hpr3466 :: Why HPR has less downloads hosted by JWP

Released: 2021-11-15. Duration: 00:09:11. Flag: Clean.
Tags: podcasts, dowloads.
A short summary on why podcast listening might be on decline.

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