Category Archives: Propagation

Make your own Dipole Antenna

Randy does such a good job of explaining how to make your own 10 Meter Dipole.  Get on the air… 10 meters is a fun band when the sun cooperates!

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Magnetic Loop Antenna

I always wondered if this type of magnetic loop antenna would “get out” to the world and how it worked.  This video shows both!

APRS… from the inventor, Bob Bruninga WB4APR

I would venture to say you can’t do better than hearing it from the inventor himself!

Published on Oct 19, 2015

Automatic Packet Reporting System overview by its inventor, Bob WB4APR given at the HACDC Amateur Radio Club. For more information about APRS, go to http://www.aprs.org For more information about HACDC Amateur Radio Club go to http://www.w3hac.org

Complete Overview of MESH for Amateur Radio (2014) by VA3BCO

MESH communications in Ham Radio is another area where Amateur Radio pushes the edge of the envelope and  has put a tremendous amount of work into this slideshare that goes from A to Z on how to run a MESH!  (Click on his website for more!)

Originally published on Nov 6, 2014

This is a comprehensive introduction to MESH for amateur radio enthusiasts. It is particularly useful for anyone new to MESH but will also include some nuggets sure to be helpful to the experienced operator. Topics include:

1. HSMM MESH vs. traditional digital modes
2. Router review & comparison
3. Firmware selection & configuration
4. Antenna considerations
5. Application scenarios for ARES and experimentation
6. Updates on local efforts & recent software announcements

Visit VA3BCO.COM for more details.

How Does a Crystal Radio Set Actually Work?

Here is an excellent YouTube video from RimstarOrg that breaks down the concept of how crystal radios actually DO their magic!  Yes, MAGIC.  Radio signals are all around us 24 hours a day.  Invisible!  You can’t really touch them.  You can’t smell them.  You can’t hear them without assistance.  We don’t really feel them bombarding us.  We don’t sense those signals without some mechanical help… but they strike us with many different frequencies constantly… so let’s explore the range of frequencies we can decipher with a homemade crystal radio set!

Crystal Radios. A blast from the past!

Many of us have looked at, or even built a crystal radio set at some point in our lives. Maybe it was in our Scouting days, youth group, science class, science fair… or just to DO IT!  The circuit itself is relatively simple to wire-up.  A long piece of wire acts like an antenna.  Some configuration of earphones or speaker will let you listen to signals.  And believe it or not, the signals are all around you!  The local AM radio station should be easy to hear.  You can even build a simple pre-amp (pre-amplifier) circuit to boost the incoming signal to add extra volume and signal strength to the fun.

Let’s understand WHY a crystal radio set is sooooooo cool!  SIMPLE CIRCUIT DESIGN.  EVEN KIDS CAN DO IT!  EASY TO GET PARTS.  NO EXTERNAL POWER REQUIRED.  INTERCEPTING INVISIBLE RADIO WAVES THAT ARE ALL AROUND US.  Plus, it’s just a pile of fun!

Here is a YouTube video from WonderstruckHow who teaches us to build a very rudimentary crystal radio set with parts that are easy enough to scrounge up.

After you watch the video check out the picture gallery of all sorts of crystal radio sets that can be built in just a short time.  They are great for kids working on a science fair project (and sure beats out a terrarium!)  Some of us “Seasoned Citizens” might actually remember the paper towel tubes or Quaker Oat cardboard cans we wound the magnet wire around and even some of the commercial kits sitting under our Christmas tree!

Near Vertical Incidence Skywave (NVIS)

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I love DX.  I love chatting to interesting people all over the world and making new friends.  For short range chatting I use our Monongalia Wireless Association W8MWA Repeater on the 144/440 frequencies.  Sometimes it’s more difficult to talk short distances than it is to talk half way around the world.  Let’s consider Near Vertical Incidence Skywave  (NVIS) antennas with our HF radios.

NVIS is something every Ham needs to learn about.  The antenna system is not difficult to construct and can serve an important function for shorter range communications, especially in time of an emergency when normal local / regional communication systems are down for some reason.  (i.e. cell towers, cellphones, landlines, etc.)  Hams may be called into service quickly.

Here is what Wikipedia says about NVIS communications…

Near vertical incidence skywave, or NVIS, is a skywave radio-wave propagation path that provides usable signals in the range between groundwave and conventional skywave distances—usually 30–400 miles (50–650 km). It is used for military and paramilitarycommunications, broadcasting,[1] especially in the tropics, and by radio amateurs. The radio waves travel near-vertically upwards into the ionosphere, where they are refracted back down and can be received within a circular region up to 650 km from the transmitter.[2] If the frequency is too high (that is, above the critical frequency of the ionospheric F layer), refraction fails to occur and if it is too low, absorption in the ionospheric D layer may reduce the signal strength.

The most reliable frequencies for NVIS communications are between 1.8 MHz and 8 MHz. Above 8 MHz, the probability of success begins to decrease, dropping to near zero at 30 MHz. Usable frequencies are dictated by local ionospheric conditions, which have a strong systematic dependence on geographical location. Common bands used in amateur radio at mid-latitudes are 3.5 MHz at night and 7 MHz during daylight, with experimental use of 5 MHz (60-meter) frequencies. Broadcasting uses the tropical broadcast bands between 2.3 and 5.06 MHz, and the international broadcast bands between 3.9 and 6.2 MHz, Military NVIS communications mostly take place on 2-4 MHz at night and on 5-7 MHz during daylight.

Optimum NVIS frequencies tend to be higher towards the tropics and lower towards the arctic regions. They are also higher during high sunspot activity years. The usable frequencies change from day to night, because sunlight causes the lowest layer of the ionosphere, called the D layer, to increase, causing attenuation of low frequencies during the day [3] while the maximum usable frequency (MUF) which is the critical frequency of the F layer rises with greater sunlight.

NVIS is most useful in mountainous areas where line-of-sight propagation at VHF or UHF frequencies is ineffective or when the communication distance is beyond the 50-mile (80 km) range of groundwave, and less than the 300–1500-mile (500–2500 km) range of lower angle sky-wave. Another interesting aspect of NVIS communication is, that direction finding of the sender is more difficult than for ground-wave communication (i.e. VHF or UHF). For broadcasters, NVIS allows coverage of an entire medium-sized country at much lower cost than with VHF (FM), and daytime coverage similar to MW (AM) nighttime coverage at lower cost and often with less interference.  https://en.wikipedia.org/wiki/Near_vertical_incidence_skywave

Below are a few very good links to articles for the nuts & bolts of putting together a simple and good NVIS antenna.

http://www.tactical-link.com/field_deployed_nvis.htm

http://www.qsl.net/wb5ude/nvis/index.html

http://www.w0ipl.net/ECom/NVIS/K2GW-NVIS.htm

http://www.w0ipl.net/ECom/NVIS/cbp-nvis.htm

Here is a sample video by NG9D with an 80 Meter End Fed NVIS Field Antenna.

2015 ARRL Field Day

Tom and Bill work on configuring Ham Radio Deluxe DM780.

Tom (KD8DQK) and Bill (WR8S) work on configuring Ham Radio Deluxe DM780 for our ARRL Field Day stations high atop the mountain.

Well… the 2015 ARRL Field Day adventure is in the books… the logbooks, that is. Having experienced decades of Field Day excursions, this one takes the cake!  What started out as a hot, sunny, humid Friday afternoon setting up our station high atop Chestnut Ridge, ended on Sunday afternoon having operated under conditions of torrential rains, a downward shift of 40 degrees in temperature, one antenna failure, one operator unable to man a station due to illness, a generator choked-out by all the moisture in the air and eventually walking around in a literal cloud!  We had three layers of clothes on and could see our breath on Sunday morning!  To say the least, it was a unique set of challenges to overcome.

Plan A was to slingshot and hang 3 doublet antennas, run 2 KX3’s for CW and PSK31, and run an Icom 7200 with a new Heil Pro 7 headset on voice.  We had a 5500 watt generator and 25 gallons of fuel to keep us purring along.  With 4 operators we had a good chance to keep all rigs racking up points for the duration.  Laptops were ready to log and the plan sounded solid.  The goal was to beat our score from Field Day 2014 and thought a good mix of voice and data would do the trick.

Our usual set-up has us mooching off of WR8S’s generosity when he goes to the trouble of of hauling his camper to the top of the mountain.  We extend the awning and set up a table or two to operate from.  Field Day 2014 was done via battery power and QRP mode.

WR8S and WD8DQK bundled up... oh wait...WR8S only brought shorts!  Wins endurance award!

WR8S and KD8DQK bundled up… oh wait…WR8S only brought shorts! Wins endurance award!

Sunday morning in a cloud!

Sunday morning in a cloud!

3 layers of clothes with hands so cold it was difficult to run DigiPan for PSK31 contacts.

WT8WV with 3 layers of clothes and hands so cold it was difficult to run DigiPan for PSK31 contacts.

The video below is a typical contest exchange using CW (Morse Code) and in the ARRL Field Day Contest an exchange of information would be the call sign of the other station, your operating mode (how many radios are you running and what sort of power and station are you running), followed by your section of the country.  Then you return your own exchange to the other station and move on the to next contact by calling “CQ FD CQ FD de WT8WV WT8WV” and hope for a return of your call sign for a confirmed contact to log.  CQ means “calling anyone”… FD means your are calling for the “Field Day” contest… de is French and means “from”… and WT8WV is our station’s “identifying call sign”.  (You will see Bill (WR8S) make a contact and then write down the exchange from the other station on the log paper… then he begins calling CQ FD CQ FD de WT8WV using a memory keyer that he can program with the CQ message, our contact information and a thank you good bye message.  He just needs to use the keyer paddles to send the other stations call sign during a contest.)  Our return message to the other station to enter into their own log was, “WT8WV 2A WV”.

The pictures below tell the story of our challenges and our solutions.  I have to admit I thought we were DOA when the generator croaked at 4:30 am on Sunaday… but we quickly came up with Plan X and realized WR8S had a converter in his truck!  Back to battery power to finish of a good run of PSK31 and CW for 2 points each!

The original team plan was to use my new call sign WT8WV and be “3 Alpha West Virginia” but Jay got sick on Friday so we were now down 1 team member and 1 radio.  Then we had a balun issue with 1 doublet antenna.  So now we are WT8WV 2A WV with 2 Elecraft K3’s and 1 antenna.  We decided to salvage our potential scores by focusing on PSK31 and WR8S’s speedy left hand on CW… and forgo voice comms.

Friday night

Friday night with Jay and Bill

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Bill’s new eBay score! SWEEEEEET!

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Tom working on busted antenna while Bill tries to thaw out from a cold night.

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Bill loading software and setting features.

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Added a 24 X 12 tarp for 3 total sides to block prevailing weather and winds.

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Generator exiled away for less QRN.

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Tom runs PSK31 as Bill logs.

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Spence working PSK31 and Bill keeps him straight.

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Bill cranking out CW contacts as Spence logs.

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Used a nice Android App to log with a bluetooth keyboard.

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Tom and Bill hook-up inverter to salvage our weekend.

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Tom saves the day! Good Boy Scout… WAS prepared.

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Tom fixed us a wonderfully WARM Sunday breakfast and we continued to grab a last string of PSK31 on 20 meters.

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A nice last hour run of CW on Sunday morning by Bill.

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PSK31 logs of confirmed QSO’s

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Bill brought a 16 foot long string of BRIGHT LED’s to light up our lives! Best gizmo of the weekend!

Radio Propagation 101 (N9LVS)

Excellent tutorial by Dan Vanevenhoven (N9LVS) on what all the numbers in a propagation report mean to amateur radio operators and their ability to broadcast every day.

20 Meters Ham Radio Band… HF… What can ya hear?

20 Meters Ham Radio Band is one of the most popular bands for long range (DX) communications.  It holds up in most conditions and is were a lot of exciting DX contacts OfficialSWLChannel tells us all about finding signals on the 14 MHz part of the band.

10 Meter Ham Radio Beacons… HF… What can ya hear?

10 Meter Ham Radio Beacons (28 MHz) help us know where propagation is working in our favor for communicating around the world.  OfficialSWLChannel provides another excellent video on how to take advantage of these beacons!

40 Meters Ham Radio Band… HF… What can ya hear?

OfficialSWLChannel tells us what we can expect on the exciting 40 Meters amateur radio frequencies.

80 Meters Ham Radio Band… HF… What can ya hear?

OfficialSWLChannel video about the activity on 80 Meters.

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160 Meters Ham Radio Band… HF… What can ya hear?

160 Meters is another challenging ham radio band to work.  This video tells you what listen for and what to expect.  This is another OfficialSWLChannel video.

6 Meters Ham Band… VHF… What can ya hear?

This is an interesting but challenging ham radio frequency band.  Sporadic E propagation is pretty cool but takes some effort.  Aurora activity in the upper atmosphere helps.  The Officialvhfuhfchannel does a good job on this video.

2 Meters Ham Band… VHF… What can ya hear?

K7AGE has a superb series of ham radio videos and I have learned a lot from them.  Subscribe to his YouTube Channel for information on TONS of topics about amateur radio!

10 Meters Ham Band… what can ya hear?

GPS and APRS… A Marriage Made In The Heavens

24satellite

How GPS Works

Basic APRS – An Introduction

Automatic Packet Reporting System (APRS)

(Click link above for the ARRL APRS webpage explaining APRS)

 The Global Positioning System, or GPS, is pretty amazing and chances are, it’s playing a much greater role in your life than you realize. Anthony explains how GPS works and tells you about some pretty cool upgrades coming soon.

GPS
http://www.gps.gov/
“Official U.S. Government information about the Global Positioning System (GPS) and related topics”

GPS Modernization Video
http://www.youtube.com/watch?v=chNQW2…

GPS is getting an $8-billion upgrade
http://articles.latimes.com/2010/may/…
“Without it, ATMs would stop spitting out cash, Wall Street could blunder billions of dollars in stock trades and clueless drivers would get lost.”

New Satellites Could Make GPS Harder to Jam
http://www.wired.com/dangerroom/2012/…
“Without GPS, drones can’t fly, communications networks can’t function, and you don’t have a chance of figuring out how to get to your Aunt Sadie’s place in New Jersey. And right now, GPS is highly vulnerable because its weak signals are coming from an aging constellation of satellites.”

How GPS Receivers Work
http://electronics.howstuffworks.com/…
“Our ancestors had to go to pretty extreme measures to keep from getting lost. They erected monumental landmarks, laboriously drafted detailed maps and learned to read the stars in the night sky.”

Check out the Air Force Collaboratory:
https://collaboratory.airforce.com/

Watch More:

How Collaboration Leads To Great Ideas
http://www.youtube.com/watch?v=ga1_a4…

How Robots Help Search And Rescue Teams
http://www.youtube.com/watch?v=i1Jztu…

Voyager 1: Where To Next?
http://www.youtube.com/watch?v=RRbG3y…

Space Weather Impacts Everyone… including amateur radio!

space weather

From the U.S. National Weather Service YouTube page… click video links below…

We rely on advanced technology for almost everything we do today. Satellite communications, GPS applications, and the electric power grid provide the backbone to our Nation’s economic vitality and national security. This technology however, is vulnerable to a threat from space — our Sun. Eruptions from the Sun can have a profound impact on society. In Boulder, Colorado NOAA space weather forecasters maintain a constant vigil on the Sun, alerting a diverse customer base when storms are imminent. Operators from many sectors will take mitigating actions to protect the critical infrastructure that we have come to depend on.

An Introduction to Space Weather and the Space Weather Prediction Center

Space Weather Impacts: Communications

Space Weather Impacts: GPS

Space Weather Impacts: Power

Radio Signal Identification (Sample Audio and Waterfall Images)

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Did you ever wonder what some of those strange radio signal beeps, boops, squeals and braps are when you tune across the radio frequencies?  Click the link below for a neat wiki page, off one of The DXZone and Sigidwiki.com website pages, that not only allows you to listen to short audio segments of them but also shows what the signal looks like in a waterfall image.

Signal Identification Guide

 

Feed Lines… A Basic Understanding

The ARRL Website has excellent information on their website about all things amateur radio.  This article explains the basics about some of the more common feed lines in use for antenna construction and the termination to your ham radio equipment.  Check the link below…

Feed Lines… ARRL.Org

The Doublet Antenna

I have helped build and used two of these Doublet Antennas during the 2014 Field Day Contest and they worked great!  Worked many stations on CW, Phone, and PSK31.  Works great across many HF bands.  A little over 120 feet long.  WR8S (Bill Shultz), WD8WQK (Tom Graf) and I are going to make one for my ham shack as soon as I order the parts. Take a look at Ray Heffer’s explanation of the Doublet Antenna and a diagram by N4UJW below.

8010doublet

Solar Super Storm of 2012 Near Miss… Ham’s Better Be Prepared

This is why ham radio operators need to be prepared for such a massive solar event.  If the rest of the grid (power and internet) were to go down, it could take a long time for it to be repaired.  Ham radio communications might become critical in every community.  Are we prepared and proficient to aid our communities?

Link to full article… Near Miss: The Solar Superstorm of July 2012

playwithlifeorg

4 out of 5 dentists recommend this WordPress.com site

BG5TLA's Blog

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Tinkertoytech's Blog

Just another WordPress.com weblog

KC4LMD

Chronicling my pursuit of amateur radio’s "Worked All Neighbors" award

Casey's Place

"When we try to pick out anything by itself, we find it hitched to everything else in the universe." -- John Muir

Hackaday

Fresh hacks every day

VK4JAZ

Writings about Amateur Radio

Tactical HF

I love the smell of ozone in the morning...smells like...radio.

WB5RMG : RadioActive Blog

slightly sub-orbital testing facility

73, de N2HTT

A blog about ham radio, Linux and more...

Ham Radio Blog PD0AC

Thoughts of a Dutch radio amateur

Silver Bells Blog

Truth Appealing...

CQ de WT8WV... GraHAM's Dits & Dah's

My journey in amateur radio intrigues and hobby interests

K5UNX Ham Radio Blog

A blog dedicated to things Ham Radio related

Mountain Mists...

A pleasant journey into how I see things... big and small

myrandomrealities

Changing my life, by changing my mind...about everything.

playwithlifeorg

4 out of 5 dentists recommend this WordPress.com site

BG5TLA's Blog

Just another WordPress.com site

Tinkertoytech's Blog

Just another WordPress.com weblog

KC4LMD

Chronicling my pursuit of amateur radio’s "Worked All Neighbors" award

Casey's Place

"When we try to pick out anything by itself, we find it hitched to everything else in the universe." -- John Muir

Hackaday

Fresh hacks every day

VK4JAZ

Writings about Amateur Radio

Tactical HF

I love the smell of ozone in the morning...smells like...radio.

WB5RMG : RadioActive Blog

slightly sub-orbital testing facility

73, de N2HTT

A blog about ham radio, Linux and more...

Ham Radio Blog PD0AC

Thoughts of a Dutch radio amateur

Silver Bells Blog

Truth Appealing...

CQ de WT8WV... GraHAM's Dits & Dah's

My journey in amateur radio intrigues and hobby interests

K5UNX Ham Radio Blog

A blog dedicated to things Ham Radio related

Mountain Mists...

A pleasant journey into how I see things... big and small

myrandomrealities

Changing my life, by changing my mind...about everything.

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