Posts tagged: Antennas

A miscellaneous post

By , April 3, 2013

ckThe team at VK9CZ spent the first few days on phone and then migrated to CW, becoming DXCC #302 (#299 with the dipole) for me soon thereafter.

Despite their posting about the lack of a reliable internet connection, I and many others had our LoTW confirmations only hours later.

That’s good because their signal was so strong that the thought crossed my mind that I’d worked a pirate although there was that tell-tale flutter.

It is currently 7:30 pm US East Coast local time and they are being received on the East Coast – on 80 meters! Normally those W4′s would be hearing Europe and Africa on 80m at that time…but VK9?! Strange propagation. Not a peep here on 80m…

.

If you’ve just started (or are thinking about) Continue reading 'A miscellaneous post'»

Photoshopping my models

By , February 25, 2013
80mdipole_20m

80m dipole on 20 meters – rotated appropriately. Click for larger.

No, it’s not what you think…

I’ve recently been manipulating a modeled version on my 80m dipole to see what type of radiation pattern it produces on other bands. Since it’s fed with 450-ohm ladder line, it is useful on all bands 10-80 meters and for several years it was my only antenna.

Its radiation pattern on 40 and 80 meters is the predictable figure 8 – but on higher bands, things get more complex with numerous lobes and nulls so I thought it might be useful to see how these characteristics were oriented in relation to the dipole’s physical orientation.

My dipole is 75ft/23m high and is oriented along an axis of 333-153 degrees. In other words, it’s 27 degrees counterclockwise from true North-South.

DX Atlas allows anyone to make an azimuthal map centered on their location. EZNEC displays a pattern of an antenna’s radiation with North at the top (or at the 3 o’clock position). Therefore, it’s a simple matter of using image editing software to rotate the EZNEC image to correspond to the real-world antenna’s orientation. Continue reading 'Photoshopping my models'»

ES5TV: 15 meter moonbounce successful!

By , February 5, 2013

erI think this a First… (see comment below)

Back in October I posted about a monster 15m antenna (read ES5TV’s description here) going up in Estonia. It is composed of eight 5-element monoband Yagis on a 230-foot (70m) tower.

Tonno ES5TV, the lucky owner, pondered at that time whether it might be possible to use such a high-gain antenna to work EME on 15 meters.

Mission Accomplished! Continue reading 'ES5TV: 15 meter moonbounce successful!'»

Force 12′s C3 vs C3E: Performance trade-offs

By , February 3, 2013

By chapter 5 of my recently-mentioned book on antenna modeling I had enough knowledge to modify an existing EZNEC model of my Yagi to include the additional 10m element I added to it shortly after installing the antenna.

Luckily for me the base Force 12 C3 has been modeled and that file is included in the software CD that comes with the ARRL Antenna Handbook. All I had to do was add the new 10m reflector that converts the C3 into a C3E and then compare the before & after to see what my trouble and $99 bought me.

The verdict: Continue reading 'Force 12′s C3 vs C3E: Performance trade-offs'»

Two very different prices for new ARRL book

By , January 31, 2013
arrl_book

From ARRL’s website – add 10.50 for shipping within CONUS

Unless you’re really in love with the ARRL and want to give your money to them, you may want to consider Amazon instead when it comes to ARRL-published books.

For many a moon now I’ve wanted to learn antenna modeling. I’ve tinkered with the programs and read about a million online guides and examples…

But for me to learn antenna modeling, someone’s going to have to take me by the hand and tip-toe me through it.

Gently. Slowly.

Ward Silver N0AX appears to have read my mind – is there anything he can’t do? I like Ward’s writing style and am confident that this is exactly the book I need.

The new book by Ward is Antenna Modeling For Beginners, published by the ARRL in October 2012.

I came within a hair’s breadth of clicking the “Order Now” button but thought I’d do a search for online reviews first. I didn’t find any reviews but the search took me to another source for the book – Amazon. Continue reading 'Two very different prices for new ARRL book'»

2012 at AE5X; and looking ahead

By , December 16, 2012

As the year draws to a close and plans are made for 2013, I like to look back and see what 2012 offered.

Thanks to the efforts of many people from many different countries I was able to add 11 entities to my “Worked” list, bringing my total to 299. Number 300 will most likely be Clipperton Island in late February 2013 although there are rumors that a very rare one will be activated perhaps before then.

These are the New Ones added to the log in 2012:

  • Malpelo – 289
  • Congo – 290
  • Wallis/Futuna – 291
  • Spratly – 292
  • Yemen – 293
  • Malta – 294
  • Afghanistan – 295
  • Christmas Island – 296
  • St. Peter & St. Paul – 297
  • Auckland/Campbell – 298
  • Monaco – 299

Misses: Swains Island (away on a biz trip) and Cambodia (can’t hear them).

After Malta, my tower and Yagi were installed but St. Peter & St. Paul were worked on 80 meters bringing my “dipole country” total to 295. Even though I now have a Yagi on 10-20 meters, I still have a goal of 300 countries with the dipole and will be chasing them not only on the low bands but also on 10-20 if I think I can get them there w/o the Yagi.

Band conditions were better on the high bands and noisier on the low bands in 2012 compared to previous years. Continue reading '2012 at AE5X; and looking ahead'»

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