ETH042 – Propagation


Hello everybody and welcome back to the Everything Ham Radio Podcast! In this episode we are going to be talking about Propagation, in the Amateur Radio Club Spotlight we will be talking about the Valley Radio Club in Eugene, OR, We talk about some upcoming events/contests and Hamfests for the next two weeks and wrap it up with some news from around the hobby!

Tech Corner – Propagation

VHF/UHF signals are all line of sight. Meaning that if there is something between you and what you are talking to, your signal may or may not be received by the receiving station. This could be a building, mountain, or even the curvature of the Earth.

Radio Horizon - Propagation
The approximate distance (in miles) to the radio horizon can be calculated by multiplying the square root of the antenna height (in feet) by 1.415 times. For example, the distance to the radio horizon for an antenna 1,000 feet above the ground is just under 45 miles

Because of the way that radio waves travel through the air and get refracted more than light waves do, you will be able to talk on the radio for a little bit longer than you can see. Radio waves travel approximately 15% farther than light waves do. For example, if you and a friend start walking away from each other on a flat surface, you would lose sight of each other at about 5 miles apart but you will still be able to talk to each other for another 30% since both you and your friend have an extra 15% each.

Knife Edge Propagation

Much like signals being reflected off the ionosphere, sometimes a VHF signal can be heard in places that are not direct line of sight from each other. If two people live on opposites side of a ragged hill, they may still be able to talk to each other and here is why. VHF signals are transmitted in a vertical polarization, so when those vertical signal strike a sharp edge of a distant  object the bottom half of the way will drag along the ground and turn the wave downward. Once the wave gets a clear light it will again travel in a straight line and since it was turned downward, it will travel down the backside of the hill, allowing you to talk to your friend. This is called Knife-edge diffraction.  

Tropospheric Scatter

Tropospheric scatter, or Tropospheric ducting as it is more commonly called, allows your signal to be caught in that layer of warm air and travel many miles before coming out of that layer and return back to the surface for reception. This occurs quite frequently over water where there is a layer of cool air along the surface level, and cool air in the upper ionosphere, but a layer of warm, moist air is held in between the two in the troposphere.

Multi-path Propagation

This occurs when the receiving station receives a signal from the same transmitter at different times. The happens because when someone transmits a signal, the radio wave takes off at all different angles. Sometimes the signal can bounce off buildings, mountains, or other surfaces or even sometimes on HF, came in from the exact opposite from the direction that you would think it would, but we will talk about this in a minute.

When the same signal comes from different directions to the same receiver because of the signal bouncing off other surfaces, it could have taken that signal longer to get to the receiver and therefore cause distortions because the signals are not in phase with each other. It could also have the opposite effect and boost the signal strength if they are in phase. There are many things that can happen with radio frequencies to make them either constructive or destructive to the receiving station.

As I mentioned above, sometimes you can receive a HF signal from the opposite direction from where you might think it should come from. Let’s say that you are in Texas and you are talking to someone in Europe somewhere. The short path would be from the East and would typically be where you would think to point your beam antenna to receive that signal. However, if you get a bad signal when you beam is pointed East, sometimes you can turn your beam around 180 degrees or so and get the signal better, this is called the Long Path.

Amateur Radio Club Spotlight

Valley Radio Club - Propagation

Valley Radio Club


The Valley Radio Club of Oregon (formerly Valley Radio Club of Eugene), located in Eugene, Oregon, was chartered in 1932, and is one of the oldest, continuously operated club stations in the United States. It has been affiliated with the American Radio Relay League (ARRL) since 1932, and associated with the American Red Cross since 1951.


  • 1st Friday at 7pm in the Red Cross Building at 862 Bethel Dr., Eugene, OR


  • 146.720 – PL 100


  • HF Net: Peak Radio Association Mondays at 7:30pm Pacific Time on 7.250 Mhz
  • HF Net: Up the Crick Thursdays at 7:30pm Pacific Time on 25.450 Mhz


  • Saturdays – Noon – 2p – Science Factory 2300 Leo Harris Pkwy, Eugene, OR. Get on the Air, Open Ham Station.
  • DX Special Interest Group
  • Testing Sessions – 2nd Wednesday at 7pm
  • Technician Classes
  • General Classes
  • Assisting in Locating sources of RFI
  • Field Day
  • March of Dimes
  • Community Service

Upcoming Events

NRAU 10m Activity Contest 1800Z-1900Z, Nov 3 (CW) and

 1900Z-2000Z, Nov 3 (SSB) and

 2000Z-2100Z, Nov 3 (FM) and

 2100Z-2200Z, Nov 3 (Dig)

NCCC RTTY Sprint 0145Z-0215Z, Nov 4
NCCC Sprint 0230Z-0300Z, Nov 4
IPARC Contest, CW 0600Z-1000Z, Nov 5 and

 1400Z-1800Z, Nov 5

Ukrainian DX Contest 1200Z, Nov 5 to 1200Z, Nov 6
RSGB International Sprint Contest, SSB 1700Z-2100Z, Nov 5
ARRL Sweepstakes Contest, CW 2100Z, Nov 5 to 0300Z, Nov 7
IPARC Contest, SSB 0600Z-1000Z, Nov 6 and

 1400Z-1800Z, Nov 6

EANET Sprint 0800Z-1200Z, Nov 6
High Speed Club CW Contest 0900Z-1100Z, Nov 6 and

 1500Z-1700Z, Nov 6

DARC 10-Meter Digital Contest 1100Z-1700Z, Nov 6
ARS Spartan Sprint 0200Z-0400Z, Nov 8
Phone Fray 0230Z-0300Z, Nov 9
CWops Mini-CWT Test 1300Z-1400Z, Nov 9 and

 1900Z-2000Z, Nov 9 and

 0300Z-0400Z, Nov 10

RSGB 80m Club Sprint, SSB 2000Z-2100Z, Nov 9
NCCC RTTY Sprint 0145Z-0215Z, Nov 11
NCCC Sprint 0230Z-0300Z, Nov 11
WAE DX Contest, RTTY 0000Z, Nov 12 to 2359Z, Nov 13
10-10 Int. Fall Contest, Digital 0001Z, Nov 12 to 2359Z, Nov 13
JIDX Phone Contest 0700Z, Nov 12 to 1300Z, Nov 13
SKCC Weekend Sprintathon 1200Z, Nov 12 to 2400Z, Nov 13
OK/OM DX Contest, CW 1200Z, Nov 12 to 1200Z, Nov 13
Kentucky QSO Party 1400Z, Nov 12 to 0200Z, Nov 13
CQ-WE Contest 1900Z-2300Z, Nov 12 (CW/Digital) and

 0100Z-0500Z, Nov 13 (Phone) and

 1900Z-2300Z, Nov 13 (Phone) and

 0100Z-0500Z, Nov 14 (CW/Digital)

Phone Fray 0230Z-0300Z, Nov 16
CWops Mini-CWT Test 1300Z-1400Z, Nov 16 and

 1900Z-2000Z, Nov 16 and

 0300Z-0400Z, Nov 17

*Information taken from the WA7BNM Contest Calendar






*Information taken from the ARRL Hamfest Calendar


Rule Making Petition to FCC Calls for Vanity Call Sign Rule Changes

The FCC is inviting comments on a Petition for Rule Making (RM-11775) from a Nevada radio amateur that seeks changes to the rules governing the Amateur Radio Vanity Call Sign Program. Christopher LaRue, W4ADL, of North Las Vegas, is proposing that any licensee obtaining a vanity call sign be required to keep it for the full license term. LaRue contends in his petition that excessive and frequent vanity call sign filings are hampering the ability of other qualified licensees to obtain vanity call signs in one of the more desirable 1 × 2 or 2 × 1 formats. LaRue said that since the FCC dropped the fee to file for a vanity call sign, some applicants are taking advantage by regularly obtaining new call signs, thereby keeping them out of circulation.

“Some are changing call signs almost monthly, just to keep the newer code-free Extra class operators from obtaining a shorter call sign,” he said in his petition. “I even saw an older operator that said he does it all the time and has not even owned a radio in over 6 years. When I looked him up, he has had 16 different [call signs] in 18 months.”

LaRue said his proposed minor rule change would require any licensee applying for and obtaining an Amateur Radio vanity call sign “be required to keep it for the duration of the license, which is currently 10 years.”

He said this would “alleviate a lot of the stress on the ULS system and manpower requirements” at the FCC. “It will also keep inactive amateurs from changing call signs regularly, thereby tying up call signs for 2 years after dismissal of said call.”

Interested parties may comment using the FCC Electronic Comment Filing System (ECFS). Comments are due within 30 days of the October 26 posting date.

California Hams Looses the ability to go mobile thanks to a new law!

As of September 26, 2016, California Governor signed the bill no. 1785 which restricts the use of any mobile radio use that requires your hands to use in the state of California.  

This is a hard hit to all amateur radio operators in California. From what i am reading from the text of the new bill, pretty much any electronic communication device is out unless you are a first responder.

The only way that I can see to get around this would be to use a headset with a foot switch, or using your radio using VOX. If you would like to read the full bill, click on the link below.

ARES/RACES Supports Office of Emergency Management during Presidential Debate

ARES/RACES volunteers stepped up to support communication for the Clark County, Nevada, Office of Emergency Management (OEM), during the third US presidential debate in Las Vegas, Nevada, on October 19. Clark County OEM Chief John Steinbeck, asked ARES/RACES to activate and support the County’s Multi-Agency Coordination Center (MACC).

Seven Clark County ARES/RACES members operated UHF and VHF voice as well as VHF packet and mesh VoIP from the MACC as well as from the Clark County IT Department communications van throughout the event. In addition, ARES/RACES members provided back-up monitoring of all event communications.

Among the Amateur Radio volunteers supporting the effort were ARRL Nevada Section Traffic Manager Jim Bassett, W1RO; Nevada Southern District Emergency Coordinator Jay Peskin, KE7EGO; Jim Davis, KF7GCT; Steve Deveny, KF7WGL; Frank Kostelac, N7ZEV, and Jack Cook, N8RRL. Also providing support from the communications van was ARES/RACES member, Keith Aurich, KD7TOF, of the Clark County IT Department.

In addition, more than a dozen Clark County ARES/RACES members remained on standby, monitoring communications from home and mobile stations, in case a wider activation was required.

Clark County ARES/RACES Emergency Coordinator Bill Smith, W7HMV, praised the ARES/RACES members who volunteered their time, equipment, and skills to support the OEM for the event.

The activation marked the first time that ARES/RACES members operated from the MACC’s new location, which, as yet, has no radio equipment installed. They were able to test and verify the capability to utilize existing external communication resources, using their own equipment from a new and potentially challenging venue. — Thanks to Jim Davis, KF7GCT


KC0W Regroups in Wake of Pacific Island Theft

Tom Callas, KC0W, who was forced to abruptly cancel the rest of his “Cows Over the World” Pacific DXpeditions after his belongings were stolen in Kiribati, has been regrouping.

“I will be in the Philippines from October 26-November 25, and the call sign will be 4I7COW,” Callas said on his profile. “This unique prefix has never been issued before, so it should generate some good interest.” Callas said he’s canceled his planned TG/KC0W DXpedition to Guatemala in favor of pending DXpeditions to Equatorial Guinea and Annobon, following his Philippines activity.

He reports “fantastic progress” in acquiring the 3C and 3C0 licenses. Equatorial Guinea is number 43 on the ClubLog DXCC Most Wanted List. Annobon is number 35. He hopes to be on the air from Equatorial Guinea and Annobon for 50 or 60 days and said to stay tuned for more information.

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73 de Curtis, K5CLM

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