Daily Archives: 16. October 2010

KA4UDX Amateur Radio Contact: PJ7E St-Maarten 15M (21 Mhz)

PJ7E-QRZ.COM-St.Maarten

pj7e-Google-Earth



And the video of KA4UDX’s contact with PJ7E – Sint Maarten on 15 Meters Band

* A special note: Normally on SSB/HF radio we operate simplex – transmitting and receiving on the same exact frequency. In this case PJ7E was transmitting on one frequency and listening on another frequency slightly higher up the band. An operator that’s paying attention would hear that he was saying “350″ – pay close attention when you listen to the video and you will hear him saying that. So I used my dual A/B VFO capability and dialed in that frequency and went into “Split” mode to listen on his TX and transmit on his RX frequency. This is kind of like Half-Duplex. You can’t really listen while you are transmitting but you are in a duplex mode with split (2 independent) frequencies. You can do other things as well such as use independant RIT and XIT – Receiver Incremental Tuning and Transmitter Incremental Tuning to do similar things. U.S. Stations will often use XIT to go slightly “off frequency” to catch the attention of the DX station. You can also use a sort of “Social Engineering” by timing your transmit to “miss” the pack of all the other stations calling – or say something special that might be heard in his or her headphones to set you apart from the MANY other stations that are calling them.

It’s a game. It’s a sport. And you are there to win. Be polite but win. You want them to hear you … you want to get the contact in your log. (As a valid contact.)

—
73 de KA4UDX,
Alan Spicer

From http://www.qrz.com/db/pj7e (see my radio contact in my next post):

Joe, W8GEX and Craig, K9CT, are the co-leaders for the upcoming St. Maarten DXpedition. Joe and Craig are pleased to announce that they have been granted permission to use PJ7E for their 10 day operation scheduled to begin on October 10th. All indications are that St. Maarten will become a “New One.”

Check out our website at www.stmaarten2010.com

QSL to Sint Maarten 2010, Box 333, Bethleham, GA 30620-9989  with a SASE please.

Sorry, no EQSL’s

source

October 10, 2010 is a special day for Sint Maarten, as they gain their independence from Dutch rule.

To celebrate this historic event, a group of experienced DXers have teamed together to put this new country on the air.

* Alan’s Note: I think other islands in the Caribbean are also becoming DXCC entities for contesting / awards recognition for Amateur Radio Operators. I’m not sure what the politics is in all of this. But it’s great to get additional chances to contact these islands / island countries – via Amateur Radio!

* Additional Information:

12-October:  From the DailyDX:

The United States Department of State has added Curacao and Sint Maarten to the “Dependencies and Areas of Special Sovereignty” list.  This now clears the way for PJ2 and PJ7 to be added to the ARRL DXCC List.  Hopefully theARRL DXCC Desk will now have everything they need in order to make the official announcement as to the new DXCC Entities from the Caribbean.  Most likely it will be four new ones, as you editor has been predicting since this past summer.

http://www.state.gov/s/inr/rls/10543.htm#note11

—

73 de KA4UDX,

Alan Spicer

KA4UDX Amateur Radio Contact: KP2/N1WON – 15 Meters (21 Mhz) US Virgin Islands

* http://www.qrz.com/db/n1won

* http://dxing.at-communication.com/en/kp2-n1won_us-virgin-islands/

* KP2/N1WON US Virgin Islands:

N1WON will be active from US Virgin Islands 12-19 October 2010 as KP2/N1WON
He will be active on HF Bands
QSL via home call

US-Virgin-Islands_KP2-N1WON

US-Virgin-Islands_St-Croix_KP2-N1WON

KP2-N1WON-Google-Earth




And the video of KA4UDX’s contact with KP2/N1WON on 15M to St. Croix – U.S. V.I.

—
73 de KA4UDX,
Alan Spicer

You can make your Ham Radio go 4000 miles why not more miles on WiFi or Cellular?

* Well because those other things just don’t work that way.

Things that travel (communicate) by radio waves are on different frequencies – usually for a reason. The Amateur Radio Bands that I am using are for the most part of what is called “Shortwave”:

http://en.wikipedia.org/wiki/Short_wave

Shortwave radio refers to the HF (high frequency) portion of the radio spectrum, between 3,000–30,000 kHz.[1] Shortwave radio received its name because the wavelengths in this band are shorter than those used for medium and low frequency bands first used for radio communications.

Initially thought to be useless, shortwave radio now has many applications where the behavior of radio waves in the Earth’s atmosphere make long-range communication possible. Shortwave radio is used for broadcasting of voice and music, and long-distance communication to ships and aircraft, or to remote areas out of reach of wired communication or other radio services. Amateur radio on these frequencies can provide hobby, educational, and emergency communication.

* A radio waves “wavelength” can be expressed as: 300 / Frequency in Mhz = Wavelength in Meters.

* Or 984 / F Mhz and 468 / F Mhz for Wavelength in Feet (984 for full sized antenna, and 468 for a 1/2 wave sized antenna).

* You can use: http://www.onlineconversion.com/frequency_wavelength.htm this online site to calculate different Mhz and Ghz frequencies into Wavelengths and get an idea of the size of full and half size antennas (and such) at certain frequencies.

You will notice that the shortwave we are talking about isn’t really short by todays standards. A full wave WiFi antenna is just under 5 inches tall. A full wave antenna in the 10 meter Ham Band can be just under 35 feet tall. 417 inches.

* The lower frequencies used in Marine, Aircraft, Amateur Radio, and such bands for distance communications are bounced back by the ionosphere often at fairly great distances. In fact I have trouble talking on some of these HF bands to friends 60, 80, 100 miles away … when I can talk to someone 800 or 1000+ miles away just fine. That would the “Skip Zone” I guess.

http://www.comportco.com/~w5alt/antennas/notes/ant-notes.php?pg=2

Ionospheric Propagation. In this mode radio waves travel in a more or less straight line until they reach the ionosphere above the earth. Due to the ionization, the waves are refracted and when the ionization is sufficient, they will bounce back toward earth. When conditions are right, there can be multiple reflections with the signal bouncing between the ionosphere and the earth several times. That is how it’s possible to propagate signals over the entire world. This mode is mainly responsible for most DX contacts on the HF amateur bands.

As a result of the geometry, it is easy to see that to communicate at large distances, the radio wave needs to leave the antenna at a relatively low angle. That allows it to move the farthest distance before bouncing off the ionosphere. Obviously, if the signal goes straight up, then it will bounce straight down and not go anywhere. As a consequence, we generally want low angle radiation for DX, but somewhat higher angles for closer communications. This will be important when we evaluate antenna designs. Unfortunately it’s much easier to install an antenna that propagates straight up due to reflections from the earth.

* * * * Anyway most higher frequency radio transmissions – such as WiFi and Cellular only travel line-of-sight and due to lower power and dissipating signals (absorbtion by materials in the path) they don’t go very far. And that is for the most part by design. WiF wasn’t meant to go TOO far. Pushing it outdoors to a couple miles is stretching its range. But it can be done with the proper equipment. WiFi wasn’t meant to go TOO far because many people use it and they could interfere with each other if the signals went too far. Something called Frequency Re-use is done everday by people without really realizing it. They are shared WiFi Channels. Everyone has them.

The same thing happens with Cellular phones and Cellular Data / Internet Cards and devices. They weren’t intended to go 50 miles much less 4000. The cell towers are designed to cover a specific area. And the next area down the road could be re-using the very same channels. Antennas are down-tilted to keep the coverage within a certain range or area and to avoid interfering with other areas, and as before to allow re-use of those same channels or frequencies.

* * * * Satellite Communications – doesn’t use short range terrestrial like WiFi or Cellular or Skywave / Ionospheric propogation like SSB/Marine/Ham Radio … the antennas are specially designed (in higher Ghz frequencies) to cover from space (either low earth orbit or geosynchronous orbit) a certain “footprint” or area. There is no (intended) reflection or skipping of the satellite signals. But they are much weaker than WiFi, Cellular, and most other radio and television (terrestrial) signals that we would be familiar with. Because of this special low noise high-gain amplifiers and specially designed (often parabolic – dish) antennas are used to transmit and receive from satellites.

Radio Amateurs can also use Amateur-made (though quite professional) satellites – even at VHF and UHF frequencies. This can even be done by small Yagi (directional) beam antennas, some even hand holdable – such as the “Arrow Antenna”.

* * * * So there you have it. It is what it is. The services and what band they are on are what they are. And this was just a little attempt to explain the why of it all. If anything it might make you seek out more information than was presented here. And that’s a good thing.

—

73 de KA4UDX,

Alan Spicer

Alan Spicer Marine Telecom and WiFiYacht.net

communications @ marinetelecom.net

+1 954-683-3426