added new blog post

content/about.md

@@ -55,7 +55,7 @@ showthedate: false
 
 Hi, I'm Michael Clemens. I'm a senior information security engineer with many years of experience in information technology. My first computer was a Commodore C64 (1989), followed by an Amiga (1992) and finally, in 1995, I got my first PC. In 1998 I installed my first Linux distribution (S.u.S.E. Linux 5.3), moved to Debian in 2002, tried a lot of BSDs and Linux distributions but always came back to Debian.
 
-I support the [Free Software Foundation Europe (fsfe.org)](https://wiki.fsfe.org/Fellows/clemens). Everything I code in my freetime is therefore published as open source software. If you are interested, you can have a look at my [projects](/projects/). I also try to document interesting stuff on my [blog](/post/).
+Everything I code in my freetime is published as open source software. If you are interested, you can have a look at my [projects](/projects/). I also try to document interesting stuff on my [blog](/post/).
 
 Besides that, I enjoy gaming on everything 8-bit (C64, Atari 2600, NES etc.) or fantasy consoles (PICO-8, TIC-80). 
 
@@ -64,3 +64,5 @@ Apart from computer related hobbies, I love analog photography, bicycles, readin
 I am a licensed ham radio operator and member of the [DARC](https://www.darc.de). My callsign is DK1MI. You can find some information about my station on my [QRZ.com page](https://qrz.com/DB/DK1MI).
 
 If you'd like to contact me, please send me a mail to [contact_0x7E5@qrz.is](mailto:contact_0x7E5@qrz.is) or send me a toot on the [Fediverse](https://social.fedihams.net/@DK1MI).
+
+This website runs on OpenBSD.

content/post/battery-benchmark.md

@@ -0,0 +1,55 @@
+---
+title: "How long can I POTA with 6200 mAh?"
+type: post
+author: micha
+date: 2023-01-02T16:00:00+02:00
+tags:
+ - Ham Radio
+ - battery
+ - POTA
+url: /battery-benchmark/
+---
+
+I've recently built two battery packs, one with six 26650 cells (14.V, 6200mAh) and one with 24 26650 cells (14.4V, 12500mAh). You can read more about them here: [DK1MI.radio: Battery Pack Building](/battery-pack-building/).
+
+Please note that the battery cells are at least 5 years old.
+
+## Setup 
+
+To find out how long the smaller pack with 6200mAh would last during portable operations such as POTA activations, I've set up the following experiment:
+
+ * Transceiver: Xiegu X5105 (set to 20m, SSB and 3W output power, using internal battery)
+ * Antenna: Dummy load
+ * Amplifier: [MX-P50M](/mx-p50m-mod/)
+ * [Microphone with built-in voice keyer](/interfacing-the-bx-184-microphone-with-the-xiegu-x5105/)
+
+![image](/img/batt_benchmark.jpg)
+
+The voice keyer was configured to play a recorded "CQ CQ etc." message that is excatly 10s long followed by a pause of 10s. The idea was to simulate SSB communication with alternating 10 seconds of transmitting and receiving. It would run forever without any timeout in this configuration.
+
+## Results
+
+I've taken measurements every 30 minutes that can be taken from the following table:
+
+| Minutes      | Voltage RX | Voltage TX  | consumed charge | PA output | TRX battery |
+| ----------- | ----------- | ----------- | ----------- | ----------- |----------- |
+| 30  | 13.3V | 13.0V | 360 mAh  | 42W | 97% |
+| 60  | 13.2V | 12.9V | 724 mAh  | 42W | 94% |
+| 90  | 13.1V | 12.8V | 1084 mAh  | 42W | 91% |
+| 120  | 13.0V | 12.8V | 1446 mAh  | 42W | 90% |
+| 150  | 12.9V | 12.8V | 1774 mAh  | 42W | 89% |
+| 180  | 12.9V | 12.8V | 2142 mAh  | 42W | 88% |
+| 210  | 12.9V | 12.8V | 2580 mAh  | 42W | 88% |
+| 240  | 12.9V | 12.8V | 2800 mAh  | 42W | 88% |
+| 270  | 12.8V | 12.7V | 3223 mAh  | 40W | 86% |
+| 300  | 12.7V | 12.5V | 3564 mAh  | 39W | 86% |
+| 330  | 12.6V | 12.5V | 3815 mAh  | 39W | 0% |
+| 360  | 11.8V | 11.5V | 4161 mAh  | 35W | 0% |
+
+The internal battery of the Xiegu dropped below 10V after 320 minutes which led to an automatic shutdown. If you take the reported percentage into account, there seems to be something wrong with either the battery or the measurement.
+
+I've stopped the experiment after 330 minutes when both the output power of the amplifier and the battery voltage has dropped significantly.
+
+## Verdict
+
+The battery seems to be a good fit for portable operations for to 5.5 hours. I was honestly surprised how stable the battery voltage is and I also assumed that more current would have drawn. The internal battery of the Xiegu also has a sufficient reserve for around 5 hours. I am not sure how much I can trust the measurements of the el cheapo battery power meter.

content/post/review-pac-12-antenna.md

@@ -10,7 +10,7 @@ tags:
  - review
 ---
 
-Since my old and proven antenna is only resonant on 20m and I did not like the fact, that the mast does not fit into any backpack, I decided to give the PAC-12 antenna system a go. I've ordered the following from Aliexpress:
+Since my old and proven antenna is only resonant on 20m and I did not like the fact that the mast does not fit into any backpack, I decided to give the PAC-12 antenna system a go. I've ordered the following from Aliexpress:
 
  * [5,6m long stainless steel whip](https://www.aliexpress.com/item/1005004662439855.html)
  * earth spike with feed point (part of the set linked above)