Adobe Flash blocked in Chrome 76

When you now run version 76 of the Google Chrome browser you will see the message shown in the screen shot excerpt below.

Click above to enlarge image.

If you click on Learn more at the right-hand side, you will see a 2017 message about the termination of Adobe Flash late next year.



 As explained in this article, Chrome now blocks Adobe Flash by default.  Flash support has been built into Chrome for a long while, thereby not requiring the user to download it separately from Adobe each time an urgent security update was needed.

Mozilla's Firefox browser will disable Flash starting in version 69.  I already have it disabled in my current version (68.0.1) of Firefox.

Based on what I see on the Adobe Flash Player download page, Flash is still supported in all versions of Windows, along with macOS and Linux. Web browsers other than Chrome may still support Flash, but the number of websites that still require Flash is rapidly shrinking.

If you still use a particular website for a service that is important to you and it will not run unless Flash is enabled, I recommend that you enable Flash only for that particular website.

John

Propagation Maps for 7 MHz

Using the VOACAP online program, I collected color-coded maps representing the predicted signal power (dB relative to 1 watt) centered on a designated transmitter site.  In the program this map is obtained from the SDBW button at the lower right corner of the main page.

I used the grid square location for W4UOA as the transmitter site and specified SSB mode, 500 W power and antenna at 33 ft (one of the limited menu selections).

The results are shown below for 1200, 1300 and 1400 UTC, encompassing the period of the RV Service net.  Below is the standard output from the program, for 1200 UTC -- covering the entire world. On the right side is a scale showing the relationship of color to the predicted received dBw signal level.

Since our area of interest for the RV Net is just the USA, I made a cropped version of each map. The results are below this one.

Click on image above for a full size view.

1200 UTC

Above is the cropped copy of the 1200 UTC map. The predicted low signal level within a few hundred miles of W4UOA is clearly seen and is consistent with the observed signal levels during the early part of the first hour of the Net.

1300 UTC

Above is the cropped version of the 1300 UTC map. The low signal (skip zone or doughnut hole) area is shrinking in size at the beginning of the second hour of the Net.

1400 UTC

Here is the 1400 UTC map, showing that good signal levels are now predicted closer to the W4UOA transmitter. This represents the end of the Net's second hour.

On a typical Thursday morning I am not able to copy W4UOA at 1300 UTC, but usually around 1330 UTC the signal comes up to a solid Q5 level. The distance from my station to W4UOA is 430 miles.

Many interesting reports and graphics are available from VOACAP, and I'm still getting acquainted with them. An excellent user guide for the online program is available at this web site. Another option for use is to download and install the program on your own computer. I may try that.

73,
John WA5MLF

AM broadcast received audio -- local and remote

Audio quality testing this morning involved reception of WWL-AM (870 kHz) on my Flex-3000 transceiver. I recorded audio samples from two places:

1. Flex-3000 speaker output
2. RCForb client program output

Below is a drawing that shows the arrangement of radio and computer software, and the software components that are involved in the two audio paths that I used for recording. I also showed the Ethernet connection to the Internet that provides the path to remote users. The testing reported here used only the data path internal to the PC and the external audio cable.

Click above to enlarge.

Here are audio recordings (about 18 seconds each) for the two audio paths. Click on each to hear the audio recording.

1. Flex-3000 speaker output via audio cable
2. RCForb client program output

Screen shots of the audio spectrum of each recording are shown below. Click on either for an expanded view.

Flex-3000 speaker output via audio cable

RCForb client program output

The RCForb graph shows high frequency content above 5000 Hz that may be due to the wide bandwidth of the Virtual Audio Channel and other data paths internal to the PC. It was not noticeable to me when listening via speakers.

John WA5MLF
 

Graphs of Maximum Usable Frequency from Ionosonde Data

In support of a forthcoming article on 40 m propagation during the daily East Coast RV Service Net, data has been collected for two ionosonde sites: one at Eglin AFB in Florida and one at Wallops Island in Virginia. The locations of ionosondes around the world can be seen at this web page. 

Thanks to Dan KC4GO for collecting data on

• critical frequency (foF2)
• MD = MUF(3000) / foF2
• Maximum Usable Frequency (MUF) 

from both sites, spanning 16 months. Data are available in plain text format from the Digital Ionogram Data Base.

The Eglin ionosonde provided 96 data sets for each day, and the Wallops Island ionosonde provided even more. Data were collected for propagation distances of 300 and 500 miles, which were chosen to represent some common distances among regular RV Net participants. The longest distance among regular participants appears to be about 1200 miles.  A review of past ionogram data shows that the MUF at 900 miles or beyond is typically about 7 MHz at the start of the 2-hour net. Shorter distances are likely to have poor to marginal propagation that improves gradually during the Net time frame.

Eglin Graphs

Below are some graphs developed from the Eglin ionosonde data. Click on any graph for a full size view.

The above graph shows the variation of MUF(300) [MUF at 300 miles] over the past 5 months, using data from 1200 UTC each day.

The above graph shows the MUF(300) at 1300 UTC on each of the dates.

 The above graph shows the MUF(500) at 1200 UTC on each of the dates.

 The above graph shows the MUF(500) at 1300 UTC on each of the dates.

 The above graph presents the variation of MUF(500) values during the 2-hour time frame of the RV Service Net.  The data points are taken from the same calendar period as the previous four graphs: 9/1/2019 thru 1/15/2019. The bottom curve shows the minimum value of MUF(500) for each time-of-day point among the 137 days.  The middle curve shows the average or mean value (across the 137 days) of MUF(500) for each time-of-day point. The top curve shows the maximum value of MUF(500) for each time-of-day point among the 137 days.

I plan to produce the same type of graph for MUF(300) [MUF at 300 miles].


Wallops Island Graphs

The above graph shows the MUF(300) at 1200 UTC on each of the dates.

The above graph shows the MUF(300) at 1300 UTC on each of the dates.

The above graph shows the MUF(500) at 1200 UTC on each of the dates.

 
The above graph shows the MUF(500) at 1300 UTC on each of the dates.



John WA5MLF

Hidden Damage to 450-ohm Balanced Line

Recently I installed new coax cable from my rig to the outdoor surge protector on the back of my garage, where the balanced feed line terminates from my multi-band dipole. This is the latest evolution of the dipole from its initial design based on pages 7 - 10 of the article Choosing the Correct Balun.  The current configuration has adopted some characteristics of a G5RV design.

While handling the 450-ohm window line I noticed that a short (1.25") section of one side of the line was able to bend at a much sharper angle than other parts of the line. Since this was part of the length I cut off, I examined it more closely by slicing away some of the insulation. The photo below shows what I saw.

Click to enlarge

It appeared that one strand of the stranded wire was still connected. I can't tell if this localized damage relates to the lightning strike in 2016 or the recent lightning strike to a nearby tree or high-power operation on 40 m or a combination of these events.

I am continuing to use and modify this antenna.

73,
John

Lightning - Sunday night

Here's a screen shot of the real time display from LightningMaps.org during a 15-minute period last night. The yellow and orange dots are the lightning detections. The blue dot is my home location.

My rain gauge collected 1.3" last night.

John

Joining Google Hangout from shared link

Here are some notes from my recent testing of joining a group Hangout on an Apple iOS device via shared link.

First, install the Google Hangouts app. The screen photo below shows the correct app to use, from the Apple App Store. There are 3 other Hangouts apps published by Google.

In order to use the app you must log in with your Google account.

My ham radio friends who meet on 3740 kHz have often used a group Hangout to supplement voice communication with live video and sharing of photos or software demonstrations / assistance. One of the group members starts a Hangout from the app on a mobile device or from a desktop / laptop computer by directing the Google Chrome web browser to hangouts.google.com.  The person starting the Hangout then copies the link for sharing (see image below) with other group members via the chatroom.  The group members can then click on the shared link to launch their Hangout apps and join the Hangout in progress.

This process works smoothly on Windows PCs, using the Google Chrome browser.  Some iPad users are able to join a group Hangout by clicking the shared link in the chatroom, viewed from the Safari browser. I have tested this multiple times successfully with a model A1474 iPad running iOS 11.4.  It is not clear whether older iPad models are able to "join via link" easily or consistently.  I've seen some indication that cookies must be enabled for the Hangouts app to work properly.

A member of a group Hangout can also send a direct invitation to another person via email, using the window shown below. Also, the copied link can be emailed to another person.

Communication between two individuals via Hangout can be initiated from the app by one person simply inviting the other.

Send me a reply if you have questions or comments.

John WA5MLF

Email addressee "auto-complete" entries

I and several friends have noticed the annoying behavior of some email applications to pull up multiple email addresses for a friend when entering part of a name or partial email ID in the To: field of a new email. With a careful search I found the following two (of many articles) that address the issue:



How to Clean Up Your Gmail Autocomplete List
I searched through my Google contacts for certain friends and did indeed find a few automatic contact entries, along with multiple email addresses saved in some of the contacts that I built myself. I weeded out the older, unused email addresses and see great improvements in what appears when I start to compose a new email.

I also found some older email addresses associated with Google+ Circles that I had assigned in the past. I had to remove these entries from the affected Circles and, where desired, add the current, valid contacts to the Circles.  Call it Spring cleaning.

How to stop old email addresses appearing automatically in the ‘To’ field in mail app
This article is specific to the Apple mail program.

73,
John

Customizing arrangement of RCForb windows

Based on discussion and screen shots shared this morning on 75 m, I explored some additional options for arranging and customizing the contents of components displayed in the RemoteHams  RCForb client window.

Below is a screen shot of the arrangement (active portions) I normally use when connected to the w4uoa remote.  These screen shots where made while the station was powered off.
(Click on any image below for a larger view.)

This arrangement has the KPA and KAT windows pinned to remain visible alongside the K3 graphic, as shown in the close-up view below.

This arrangement can be tailored by adjusting the boundaries among the 3 tiled windows, as illustrated below.

It is possible to drag the KPA window or the KAT window (or both) away from the pinned position to any other place on the Windows desktop.


The next screen shot shows the KPA window overlapping the K3 and KAT windows -- not a useful arrangement.  The window can be dragged away from the RCForb window completely, if desired. The pinned arrangement is probably preferred by most users.











A floating window like the above can be returned to the RCForb main window by drag-and-drop as shown below.

Click and hold on the top of this floating KPA window and move the mouse pointer toward the top right. A blue shaded area shows the current position based on the mouse pointer. A cross icon appears indicating possible landing positions for the window when the mouse button is released.

This view shows the selected landing position of the window.
















Another display option is to auto-hide the KPA and/or KAT windows.

This view shows both windows auto-hiding. When the mouse pointer is moved onto one of these tabs, the window will open for viewing, until the mouse pointer is moved away.

This view shows the KPA window pinned, so it displays full-time, while the KAT window is auto-hiding.










Comments and questions are welcome.
WA5MLF

Cryptocurrency and Blockchain

Here are some informative links about cryptocurrency (Bitcoin is the first and best-known) and the enabling Blockchain technology.


Cryptocurrency
The introduction and Overview in this article provide a good quick view of the topic, including the concept of a production cap that limits the ultimate amount of the currency in circulation.


Cryptocurrency Mining
In the early years of Bitcoin, computer users were able to run software to "mine" new Bitcoins. Over time this has become much harder, requiring great amounts of electrical power and computer processing power. This article from 2015 describes the  futility for an average PC user.

Update - January 11:
The large-scale mining of Bitcoin was explored in a visit by CNBC to the Wenatchee, WA location of Salcido Enterprises. This facility takes advantage of cheap electrical power to operate 1800 servers that mine 5 to 7 Bitcoins per day. The current power consumption is 7.5 MW, costing $200,000 per month. The CEO hopes to mine 50 Bitcoins per day by July, consuming 40 MW. Salcido is one of 12 companies in the area who are mining Bitcoins. Four companies have requested 100 MW of electrical power from the local utility.

You can view one of the CNBC video segments at this link.


Coinbase
This is probably the best-known site for exchanging ordinary currency into Bitcoin and other popular cryptocurrency.

Special Report: Blockchain World
This series of articles from IEEE Spectrum has LOTS of detail on the subject and its application to transactions far beyond cryptocurrency. 

Test of blog post from outside email

Test of blog post from outside email. Sent by John on 10/31/17.

Test of email post to blog

Test of posting to blog via email. 10/31/17

 

 

WiFi Analyzer Apps

Here is a collection of some links to apps that enable you to analyze and troubleshoot your WiFi configuration and coverage at a given site.

iOS

Network Analyzer - wifi scanner, speed test, tools
For iOS devices, but does not have all the WiFi details that are available on other platforms

Mac OS
7 Best Wifi Analyzers for Mac OS

Windows and Mac
9 free Wi-Fi stumbling and surveying tools
Slides 3 and 9 are Mac apps

Android
8 Best WiFi Analyzer And WiFi Scanner Apps For Android

Linux

• Kismet Wireless
• LinSSD
• Wavemon
• Network manager command line interface: nmcli d wifi
• Wireless LAN Sniffer Applications and Scanners for Linux
  -- a long list that includes some of the above

Also see:
How to Find the Best Wi-Fi Channel for Your Router on Any Operating System

VOACAP 7191 kHz - Aug 24 at 0715

 

Best signal would be indicated by green and blue contour lines, but they are missing today. Not the best conditions.

HF Radio Propagation Modeling

Below is a series of cropped screen shots I collected at 0830 CDT today from the VOACAP map feature of the KE9NS PowerSDR software that I am currently using. My station location is marked with the red star. The predicted signal level scale ranges from blue (strongest) to green to yellow to orange to gray (weakest). Only the 30 m plot has gray contour lines. The 60 m plot has vertical lines that mark two of the defined frequency channels.

During earlier discussion of this topic, Tom KQ5S told us about the VOACAP propagation modeling presented on the K6TU web site. The link I provided here gives an overview of what's needed to run the model program on the web site.

A little web searching today about "do-it-yourself" VOACAP usage brought the following article from 2004:

An Introductory Tutorial to VOACAP

Two other search results raised my awareness of the VOACAP dependence on sunspot data and how it is defined and published:

• VOACAP Quick Guide  See the notes under the red text.
• The Sunspot Number

My searching today reminded me that the VOACAP capability is also a plug-in built into the 4nec2 antenna modeling software that I use. I've seen it in one of the program menus, but have not digested the documentation enough to use it.

John WA5MLF

BRARC-80th

160 m Dipole - Old and New

Here is a series of plots that compare the radiation patterns of two versions of multi-band dipole antennas at KB0BH:

• Old dipole: 240 ft end-to-end, 35 ft high, 450-ohm balanced line feed
• New dipole: 230 ft end-to-end, 60 ft high, 450-ohm balanced line feed

Modeling for the old dipole includes the fact that 20 ft on each end hangs down vertically.
The graphics below include horizontally polarized pattern in the horizontal plane and vertically polarized pattern in the vertical plane. Three frequencies were analyzed (1.9, 3.7, 7.2 MHz). The frequencies are identified near the upper left corner of each plot.

In all cases the antenna structure is oriented from left to right on the plots. 

Each plot shows the patterns for both antenna cases, for comparison. The color legend is shown at the lower left corner of each plot. Numerical markers for maximum gain and beam width are for the new dipole. Click on any image for a full size view.

The software can provide additional types of radiation patterns.

Map of QSO participants

I updated a pair of Google Earth map views to show the locations of participants in our morning round table QSOs on 75 m. These are extensions of the earlier maps I made a few years ago of participants in the Saturday Bell Ringers Net. Click on either graphic below for a full-size view. The place marker dot, not the call sign label, represents the location of each station.

The view above shows frequent and infrequent participants. Four range circles, centered on W4BXI, are labeled with each radius in miles.

This second view is zoomed in to better display the stations within 100 miles of W4BXI.

Baluns -- Under the Hood

Below are views of 3 baluns that I own, with their covers removed to see the internals. The first photo shows 2 LDG baluns that are rated for 200 W. The one on the left is a 1:1 current or choke-type balun. The one on the right is a 4:1 balun that appears to be a voltage-type balun.  For some in-depth discussion of balun types, see this article by W7EL.

LDG baluns

1:1 Current Balun

4:1 Voltage Balun

Above are schematics of the two LDG baluns, using graphics from the W7EL article.

The next 4 photos show the internals of a DX Engineering balun DXE-BAL050-H10-AT that is rated for 5 kW CW and 10 kW SSB.

-  John