WA5MLF

Tuesday, May 3, 2016

Frequent Lightning Disrupting 75 m

Frequent lightning on the morning of 4/27/16 dominated my reception on 3740 kHz (and all of the 75 m band). The 24-hour map of lightning below shows where the activity was located. Yellow represents data that is up to 15 minutes old, relative to 0535 CDT. Orange is up to 2 hours old, and red through blue represent data that is 2 to 24 hours old.


From LightningMaps.org - Click to enlarge.

My SDR receiver display below shows that static crashes were very frequent and very broad-banded.The top part of the display is the panadapter format, with signal level represented on the vertical scale and frequency (kHz) on the horizontal scale. The bottom part of the display is the waterfall format, with time progressing vertically down the display, frequency on the horizontal scale, and average signal level represented by color.


Panafall display at 0623 CDT - click to enlarge

Compare this display with the one in my earlier post that showed less frequent lightning activity compared with a nice strong signal from W4PRE.

Wednesday, April 20, 2016

Static crashes vs W4PRE

W4PRE signal at 0614 CDT, interrupted by static crashes from storms in Texas. Phil was S9+18 when captured.

Below is a wider view showing static crashes.

Thursday, January 21, 2016

Weather Sites

The web offers us many richly-detailed web sites devoted to weather. Here is a list of many of the best known, and a few others, in no particular order:

National Weather Service

Storm Prediction Center

Lightning data maps:

Friday, January 15, 2016

Linux Distributions and Desktop Environments

We've had recurring discussions on HF radio about Linux, especially following the end of Microsoft support for Windows XP and the arrival of Windows 10. For some Windows users, Linux offers an effective alternative to upgrading or replacing older hardware. I've used Linux for many years on an alternating basis with Windows. Currently I use only two applications at home that do not have Linux versions or equivalents, and my understanding is that they do not run under the Wine software that enables many Windows programs to run on Linux. At my part-time job I am supporting Windows 7 computers, so it is helpful to maintain familiarity with that environment.

Linux provides many opportunities to learn more about computers and networking, and has many capabilities that are less common or are absent from Windows. Occasionally these have been helpful for me to troubleshoot computer hardware and network connections, and have helped to distinguish between hardware and operating system software troubles.

Most users of personal computers can accomplish the majority of their routine tasks with software applications on Linux. System maintenance does require some new learning, but all who use and maintain Windows today had to learn to use it, too.

For my friends who are curious about Linux and want to try it out or even use it part time or full time, I assembled this collection of web links that address the following topic areas:

Linux challenges & tips
Choosing a Linux distribution
Choosing a desktop environment
Trying Linux without installation

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Linux Challenges & Tips

Why it's not mainstream - This article explores some of the issues that inhibit greater adoption for desktop computers. As noted above, you need to be willing to learn if you want to install and use this operating system. Most Windows users are using computers with Windows pre-installed. There are a few computers available for purchase with Linux pre-installed.
Rules for a new Linux user - The author gives some tips for the new user. Her recommendation of carefully choosing your first distribution relates to my second topic area below. She includes a link to a separate article to cover the question "should I use Linux".
Helpful Communities - This lists some of the communities that are good resources for finding resolutions to problems encountered. There are general Linux communities as well as distro-specific communities.
Tips & how-to articles:

Linux collection from How to Geek
Tips & Tricks collection from Make Tech Easier

Choosing a Linux Distribution

Best Linux Distributions for Beginners
10 Linux Distributions Compared
The Best Linux Distributions
DistroWatch provides a comprehensive catalog of distributions (BSD and Solaris in addition to Linux) with details, applications, reviews and download links for each. You can browse, list the major distros or search based on your criteria, such as older hardware.
Windows 7 >> Elementary OS

Choosing a Desktop Environment (DE) (e.g. GUI)
You select a distribution and use its included default DE or change the DE after installation.

Environments for Ubuntu - Be sure to see the How To Get It section under each DE description.
5 Best Desktop Environments - with pros and cons of each
Another 5 Best Desktop Environments list
Top 10 Desktop Environments

Trying Linux Without Installation
Many computer hobbyists like to download a Linux distro and try it out before installing. There are two options for this

CD /DVD - After downloading the chosen Linux distro ISO (disk image) file you use a program that can burn a CD or DVD with the ISO file. You can then boot the computer from this disk, but the performance is limited by the slow speed of the optical drive.
USB Flash Drive - Better performance is obtained by running Linux from a USB flash drive, but not all computers can boot from USB. Here are some of the available programs for making a bootable USB flash drive with your chosen Linux distro:

A bootable Linux CD or DVD is a good tool to keep for troubleshooting on any computer.

Wednesday, December 16, 2015

G5RV vs Loop noise

G5RV on left, Loop on right, as seen in the Audacity audio editing program from Skype audio connected to W4UOA's transceiver. The recording was made at 9:10 am CST, when 75 m was no longer ideal for the 430-mile path between me and Carl.

Below are partial screen captures from the audio recording at three selected time segments.