I had a heavy case of 'Oh Shiny!' this weekend. Recently I've been viewing
and listening some DJ mixes on YouTube, most of them with music from the 1980s
which I appreciate a lot.
Seeing those DJs mix live in those videos made me wonder 'how do they do it'.
In one or more of these mixes I really noticed that a transition seemed to have
happened between one well-known song and another, but I wasn't aware of how and
when the transition happened. The DJ was so good in mixing the two records
together I couldn't hear the point where it happened. In seeking the video I
saw that other people viewing the video had been wondering the same, there was
clearly a peak in viewing time on the transitions. It was also clear from the
look on the face of the DJ he was happy with what he accomplished with that
transition!
In the 1980s the DJ had an audio mixer and two turntables, almost always the
Technics SL1200 with pitch control and fast start/stop. Nowadays this can
be done in software. From a music collection on harddisk with controls to
mix 2 or 4 tracks, with effects, equalizer and speed control. The modern
DJ has a laptop!
I soon found out there is open source DJ mixing software that supports Linux!
Mixxx - Free DJ Mixing Software App
is open source and multiplatform. And it is available as an Ubuntu package so I
gave it a spin (pun intended). Only having one audio device is 'supported' but
it took me some trying to find a setup where I could work 'split' with a master
mix in one ear and a headphone mix in the other. So I loaded some music and
tried to make it into a bit of a DJ mix. I'm not very good at it, but I
enjoyed trying.
Mixxx really prefers Jack audio since it likes having a lot of audio channels.
I tried installing Jack audio in linux but couldn't get it to do what I want
fast. Mixxx also supports the Alsa drivers and I managed to also set it up to
route the main audio to a USB audio device and the headphone audio to the
internal headphone jack. But I had nothing connected to the USB audio device
and I didn't want to annoy my family with the noises of trying to make a good
cutover from one song to the next. Mixxx has an option 'Split' to play the
master output to one ear of the headphones and the headphone output to
another, this is good for practicing.
Control of all the mixing functions in Mixxx can be done with mouse and
keyboard, but the good part is it also supports all kinds of hardware DJ
controllers. And some of them aren't too expensive... and available on the
second hand market for an even better price.
As I am working towards getting 100 countries confirmed in morse I do keep
an overview of countries I have at least one contact with which isn't
confirmed yet on Logbook of The World (LoTW). On LoTW a contact is only
confirmed when both sides upload a signed log with the same contact.
Yes, LoTW uses X509 certificates and signing, they just hide it mostly from
the user.
So when I have a country in the log where I'd like to get digital confirmation
I follow a few steps:
I first check the page for the callsign on qrz.com. Most radio amateurs
maintain a presence on that site and may mention their policy for confirming
contacts. Especially for rare entities where other radio amateurs will be
interested in getting those entities confirmed.
If that page doesn't answer this question the next step is to check the call
(or calls) with the 'find call' option in LoTW. Here it is possible to see what
the last time is a log was uploaded and processed for that call. Or it shows
that the call isn't active on LoTW at all. In that case I stop searching.
Using LoTW is somewhat complicated and I don't feel the need to convince
someone to start using it.
If the amateur is active on LoTW I try to guess whether regular uploads can be
expected. Some have not uploaded anything in years, others seem to upload once
a year in the month of January. Or the amateur uploads somewhat irregularly.
Now I am nearing 100 countries confirmed in morse I do sometimes write an
e-mail to the amateur asking to confirm the contact if I haven't seen
confirmation after a few months. With all the details needed to find the
contact in the log so they only have to do minimal work to look up the contact.
Getting Nothern-Ireland confirmed
In amateur radio Northern-Ireland is a separate entity and I had a few morse
contacts with stations in Northern-Ireland in the log but none confirmed, not
even after 3 months. So I mailed two of them which are regularly active on
LoTW. The first one responded after a few days with a screenshot of the
confirmed contact.
So now I have 91 countries confirmed in morse on LoTW. The certificate for
100 countries in morse is getting closer!
In preparation for a migration at work I wanted to do actual benchmarking of
Linux filesystem performance. I think I used bonnie in the last century, so
I gave bonnie++ a spin for this.
I have little idea of what 'good' or 'bad' numbers are from bonnie++. I could
only compare a "local" filesystem with an NFS filesystem. I use local in quotes
because this was in a virtual machine, so it's SSD storage in raid-1, with LVM
on top of it, with a logical volume assigned to a KVM-based virtual machine,
which uses the virtio disk driver for an ext4 filesystem.
The numbers for the "local" filesystem:
Now I am somewhat confused. Sequential write to NFS is slightly faster.
Update 2023-08-08
At work I got different but comparable numbers for iscsi attached storage
versus vmware storage (and the layers in between). Those numbers helped make
decisions about the storage.
Thanks to my participation in the IARU HF Contest 2023
and my participation in the preparation period just before the
CQ WPX CW Contest
I now have two new countries confirmed in morse: San Marino and Argentina.
This brings me to 90 countries confirmed in morse.
This proves again that contests are a way to get more countries in morse in
the log and confirmed.
This weekend was the IARU HF World Championship
contest and I was planning to participate. This is one of my favourite
contests. I made sure the software was all set up correctly before the weekend.
This year the IARU-HF contest is also the World Radiosport Team Championship,
this edition in Bologna, Italy. I see 58 stations active in the WRTC, I have
41 in my log.
I participated on the 10, 20 and 40 meter bands, I had no access to 15 meter
this time. In total I made 212 contacts, all in Morse. The results according
to my contestlogger:
Only a few contacts were outside Europe, not a lot of DX this time. Local
interference on 20 and 40 meters limited me to stronger stations. I called
CQ on the 10 meter band for a while since I was able to hear returning signals
in the noise, that only gave me one contact, but with a station at the World
Radiosport Team Championship, so that was cool.
The log submission website gives the calculated score as Raw Score: 566 Qpts x 56 Mults = 31,696 (212 QSOs)
so just like last year I still have to look at the calculations.
This weekend is the IARU HF contest and I will participate. This year it
is extra special because the IARU HF contest is also the World Radiosport Team Championship
which is in Italy this year.
I will try to get the WRTC calls in the log, but I'm also looking forward to
getting contacts all over the world. I will concentrate on morse and maybe
get some phone contacts too.
My earlier failure with an RFID T5577 tag that came with the proxmark3
made me order a bunch of new ones via 10 Pcs T5577 writable RFID tag and while I was
browsing that store I found 100 pcs ntag213 NFC sticker and I had some ideas for Mifare
Ultralight tags, starting with
failing to convert used public transport tickets to NDEF tags.
Today the package came in and the first thing I wanted to do was set up an
Mifare Ultralight as NDEF tag. The fun part is the tag was already set up
that way, so with NXP tagwriter for Android it was really easy to put a
data set with an URL on a tag. Full log below.
The downside is that the tag can't be reset to use for other things than NDEF
tag, since the NDEF identifier is in the one-time-programmable bits. An attempt
to zero out these bits on a tag indeed failed. Reading the NT2H1311G0DU
datasheet makes me realize this is as intended and matches the 'ntag213' in
the description.
The fun part is that scanning the tag with my samsung phone opens the url,
no questions asked. This behavior inspired me to set up a tag to link to the
2023 version of the Rickroll. I see security implications from just opening
a URL without letting the user decide whether this is a good idea.
I'm always looking for new entities in amateur radio to contact. Sometimes they
happen because I knew amateur radio activity was going to happen from that
location, and sometimes it's just because I notice a new country when looking
for contacts on the radio.
The recent contacts to Vietnam and Cayman Islands were of the latter category,
just checking for available contacts in FT8 and noticing a callsign from a
rare (for me) entity.
Ducie Island was clearly of the former category and I checked for a time when
I could get them in the log. When I got the contact, it went easier than I
expected!
Ducie Island is of the very rare category, and a special kind of activation
as described in VP6A – Ducie Island - DX-World.
The minimal amount of equipment was set up on the island in waterproof boxes
with radio's and connected antennas. It was powered with a generator and a few
operators retreated to a boat nearby so they did not have to camp on the island
or clean up. The other operators weren't even nearby but operated the equipment
remotely via satellite Internet. This may seem 'cheating' but the radio and
antenna making the contact are in the DX location, the person operating it
is just somewhere else, limiting impact on the location.
Especially with islands that are nature reserves and have really strict rules
about people visiting the island can benefit from this approach.
While working with the other NFC tags I had a crazy idea: what if I can
'recycle' used one-time public transport tickets as NDEF tags. The one-time
public transport tickets are mifare ultralight tags just like the
touchatag tag.
I had a heavy case of 'Oh Shiny!' this weekend. Recently I've been viewing and listening some DJ mixes on YouTube, most of them with music from the 1980s which I appreciate a lot. Seeing those DJs mix live in those videos made me wonder 'how do they do it'. In one or more of these mixes I really noticed that a transition seemed to have happened between one well-known song and another, but I wasn't aware of how and when the transition happened. The DJ was so good in mixing the two records together I couldn't hear the point where it happened. In seeking the video I saw that other people viewing the video had been wondering the same, there was clearly a peak in viewing time on the transitions. It was also clear from the look on the face of the DJ he was happy with what he accomplished with that transition! In the 1980s the DJ had an audio mixer and two turntables, almost always the Technics SL1200 with pitch control and fast start/stop. Nowadays this can be done in software. From a music collection on harddisk with controls to mix 2 or 4 tracks, with effects, equalizer and speed control. The modern DJ has a laptop! I soon found out there is open source DJ mixing software that supports Linux! Mixxx - Free DJ Mixing Software App is open source and multiplatform. And it is available as an Ubuntu package so I gave it a spin (pun intended). Only having one audio device is 'supported' but it took me some trying to find a setup where I could work 'split' with a master mix in one ear and a headphone mix in the other. So I loaded some music and tried to make it into a bit of a DJ mix. I'm not very good at it, but I enjoyed trying. Mixxx really prefers Jack audio since it likes having a lot of audio channels. I tried installing Jack audio in linux but couldn't get it to do what I want fast. Mixxx also supports the Alsa drivers and I managed to also set it up to route the main audio to a USB audio device and the headphone audio to the internal headphone jack. But I had nothing connected to the USB audio device and I didn't want to annoy my family with the noises of trying to make a good cutover from one song to the next. Mixxx has an option 'Split' to play the master output to one ear of the headphones and the headphone output to another, this is good for practicing. Control of all the mixing functions in Mixxx can be done with mouse and keyboard, but the good part is it also supports all kinds of hardware DJ controllers. And some of them aren't too expensive... and available on the second hand market for an even better price.
I had a heavy case of 'Oh Shiny!' this weekend. Recently I've been viewing
and listening some DJ mixes on YouTube, most of them with music from the 1980s
which I appreciate a lot.
Seeing those DJs mix live in those videos made me wonder 'how do they do it'.
In one or more of these mixes I really noticed that a transition seemed to have
happened between one well-known song and another, but I wasn't aware of how and
when the transition happened. The DJ was so good in mixing the two records
together I couldn't hear the point where it happened. In seeking the video I
saw that other people viewing the video had been wondering the same, there was
clearly a peak in viewing time on the transitions. It was also clear from the
look on the face of the DJ he was happy with what he accomplished with that
transition!
In the 1980s the DJ had an audio mixer and two turntables, almost always the
Technics SL1200 with pitch control and fast start/stop. Nowadays this can
be done in software. From a music collection on harddisk with controls to
mix 2 or 4 tracks, with effects, equalizer and speed control. The modern
DJ has a laptop!
I soon found out there is open source DJ mixing software that supports Linux!
