Jon Harder
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ng0e.bsky.social
Jon Harder
@ng0e.bsky.social
58 followers 54 following 67 posts
Creator and maintainer of
• vhf.dxview.org
• hf.dxview.org
Posts Replies Media Videos
ng0e.bsky.social
There are now two ways to bookmark the HF+ propagation map:

By band: hf.dxview.org/band/14 — set the band to the given MHz. Valid band numbers are 1, 3, 5, 7, 10, 14, 18, 21, 24, 28, and 50.

By location (grid square):
hf.dxview.org/perspective/...

#hamradio
Browser address bar showing link to a particular perspective.
November 15, 2025 at 12:03 AM
ng0e.bsky.social
An update to the VHF propagation map has been uploaded. It has a number of fixes including better representation of activity that is adjacent to the international dateline, particularly for New Zealand.

vhf.dxview.org
#hamradio #newzealand
VHF propagation map show activity between Aukland and Wellington, New Zealand.
November 12, 2025 at 12:38 AM
ng0e.bsky.social
Happening now: I think this is legitimate propagation from Wichita to northern Mississippi. Can anyone on the ground confirm?

vhf.dxview.org
#hamradio
VHF propagation map showing activity from Wichita to northern Mississippi.
September 25, 2025 at 1:06 PM
ng0e.bsky.social
Enhancements for mobile devices have been completed for the HF propagation map.

Most visitors to the HF map are using a phone or tablet. The experience on phones and tablets is much improved now.

The changes will be activated the next time you open or refresh the site.

hf.dxview.org
#hamradio
A HF prediction for the 14 MHz band centered on Asia as captured by a phone screenshot.
September 25, 2025 at 12:11 AM
ng0e.bsky.social
ANNOUNCEMENT: the process of optimizing the HF+ propagation map for mobile devices has started. The app is working much better on small screens now. The band selection bar appears conveniently at the top of the screen.

hf.dxview.org
#hamradio
10 MHz propagation map showing western Europe on a phone screen.
September 18, 2025 at 1:03 AM
ng0e.bsky.social
The VHF propagation map is working much better for mobile devices now. A significant number of visitors use mobile or tablet devices and this will greatly improve their experience.

Let me know if something should be working better!

vhf.dxview.org
#HamRadio
VHF propagation map of central Europe.
September 12, 2025 at 1:27 AM
Reposted by Jon Harder
n4jaw.bsky.social
The Latest Ham On A Bike Blogpost is out. There's One Line I Don't Mind Waiting In. "THE GRAY-LINE or GREY-LINE". #AmateurRadio #HamRadio #grayline #greyline #DX #HFpropagation #GraylinePropagation
Jon @ng0e.bsky.social you were referenced in this blog.
hamonabike.blogspot.com/2025/09/ther...
There's One Line I Don't Mind Waiting In. "THE GRAY-LINE or GREY-LINE"
hamonabike.blogspot.com
September 6, 2025 at 5:57 PM
ng0e.bsky.social
ANNOUNCEMENT: the VHF propagation map is being optimized for tablets and mobile devices. It is working much better for the smaller screens.

There are a few differences between mouse- and touch-based interaction:

vhf.dxview.org
#hamradio
Screenshot from a phone showing VHF propagation centered on Germany.
September 4, 2025 at 11:38 PM
ng0e.bsky.social
The VHF propagation map will start showing more activity. A coding error when translating from Rails to Rust caused some activity to be filtered inappropriately.

vhf.dxview.org
#hamradio
VHF propagation map of the NE USA.
September 4, 2025 at 10:58 PM
Reposted by Jon Harder
garyhornseth.bsky.social
A website that lets you select a country or state and move it around a Mercator projection map to yield better size comparisons.

thetruesize.com, created by James Talmage and Damon Maneice
Five rescaled maps of Minnesota on a Mercator projection map, covering 1) a large part of northern Greenland, 2) a large part of northern Scandinavia, 3) a part of central Europe, 4) a region of southern India, 5) a region of southeastern Australia.
August 30, 2025 at 11:34 PM
ng0e.bsky.social
Today some corrections and enhancements were applied to the VHF propagation map.

The changes improve the interaction as the pointer is moved over active stations. A white outline adds contrast to the footprint and when selected the paths are clearly revealed.

vhf.dxview.org
#hamradio
A VHF propagation map highlighting a station in Turkey.
August 30, 2025 at 11:15 PM
ng0e.bsky.social
ANNOUNCEMENT: The HF propagation map now has an option to display the gray line. This feature is activated with a checkbox in the main menu.

hf.dxview.org
#HamRadio
HF propagation map showing the gray line feature and the associated menu option.
August 28, 2025 at 11:09 PM
ng0e.bsky.social
Of all the the lighthouses on the air this past weekend, 7S0SFJ in Sweden is one of the unique ones. The station is on the "Finngrundet," a lightship that was in service from 1903 to 1969.

www.sjohistoriska.se/en/visit/the...

#hamradio #lighthouse
"Lightship No. 25 Finngrundet" in port.
August 19, 2025 at 1:33 AM
ng0e.bsky.social
Here is an unexpected mid-ocean HF propagation data point. KQ6RS reports this WSPR equipped buoy drifting in the North Atlantic is a high school project. During your station's off time, set up WSPR on 20m to see if it picks up the 0.01W signal!

www.qrz.com/db/KQ6RS
hf.dxview.org
#hamradio
A yellow buoy with solar panels and antenna bobbing in the ocean. KQ6RS photo.
July 26, 2025 at 11:05 PM
ng0e.bsky.social
VY0ERC is another far-north amateur operation on the HF propagation map. The club station is at the Eureka Weather Station on Ellesmere Island in Nunavut (Canada). Listen for them on FT8.

FT8 activity: rbn.telegraphy.de/activity/VY0...
Ellesmere propagation: hf.dxview.org/perspective/...

#hamradio
Three musk oxen in a snowy landscape. VY0ERC photo
July 25, 2025 at 1:44 AM
ng0e.bsky.social
Have you ever wondered why the HF map has propagation from the far north? Polarstern is a German polar research vessel. It is active as DP0POL using WSPR on 7, 10, 14, and 18 MHz. Today it is above 84º N latitude.

Follow DP0POL on WSPR: www.wsprnet.org/olddb?mode=h...

hf.dxview.org
#hamradio
The German polar research vessel Polarstern as it navigates sea ice.
July 24, 2025 at 1:06 AM
ng0e.bsky.social
The HF propagation predictions charts are working better after correcting errors introduced in the conversion to Rust.

The chart shows hours of the day going from left to right, starting at 0000Z (UTC). The red vertical bar is the current time.

Color coding shows SSB, CW, FT8 or WSPR.

#HamRadio
HF propagation chart between grid squares EN23 and EM71, showing hours 0000Z to 2400Z on the 18Mhz band. The chart is color coded showing SSB, CW and FT8 levels.
July 18, 2025 at 12:58 AM
ng0e.bsky.social
Drawing areas of propagation that cross the 180th meridian (International Date Line) on the HF map have always been a mathematical challenge. A bit ago an update was uploaded that finally gets it right (I think). Errors had been showing up particularly on 20 meters.

hf.dxview.org
#hamradio
A man stands on the International Dateline in Fiji with the left side labeled "Today" and the right side "Yesterday."
July 13, 2025 at 1:45 AM
ng0e.bsky.social
The HF propagation map is now running on all Rust code.

An error in the activity view resulted in missing data, including a blank map for 10 Mhz. That and some other minor things have been fixed.

hf.dxview.org
#hamradio
A map of activity on the 20m amateur radio band showing station C94RRC in Mozambique.
July 8, 2025 at 11:18 PM
ng0e.bsky.social
Ever since switching the VHF (APRS) data gathering app to Rust there has been a persistent memory leak.

I finally had time to dig in and resolve the problem. Now it stays around the 150-160M range. In contrast the HF data gathering app, sits around 100M.

vhf.dxview.org
#hamradio
View of aprs app status showing 158.6M memory in use.
July 2, 2025 at 9:23 PM
ng0e.bsky.social
The VHF site was having problems related to file compression on some older Safari browsers. I believe that is all sorted out. Compression is fairly easy to implement with the Rust system being used, but leave it to me to overthink things.

vhf.dxview.org

#hamradio
Rust line of code: .wrap(Compress::default())
June 30, 2025 at 11:22 PM
ng0e.bsky.social
The HF+ propagation map ( hf.dxview.org ) is most useful when you select your location by clicking on the map (or entering your grid square, if you know it). This allows you to see where in the world you are likely to make contacts on any band.

#hamradio
Map showing HF propagation on the 20m band.
June 27, 2025 at 8:09 PM
ng0e.bsky.social
The VHF propagation map ( vhf.dxview.org ) has recently completed conversion to the Rust language, away from Ruby on Rails. It is very fast and is improving as performance updates are applied.

#hamradio
Map of VHF propagation for the upper midwest of the US.
June 27, 2025 at 8:00 PM
ng0e.bsky.social
I am an amateur radio operator who maintains the real-time HF+ and VHF propagation sites.

The HF map has two modes: global activity per band and propagation unique to the user's location.

The VHF map is useful for showing areas of enhanced propagation, typically tropospheric ducting.

#hamradio
Map showing current propagation on the 20 meter band Map showing current VHF propagation.
June 27, 2025 at 7:53 PM