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Friday, July 31, 2009

Hustler 5BTV Performance Results

Here are the performance results from the Hustler 5BTV (4BTV with 80M add-on). Click on the image for a larger view. This is the data before I built the final transceiver end 1:1 balun, its the temporary balun (black coax). Also, 80M was not tuned and 40M was not quite finished being tuned but close. 10M is also almost a 1.1:1 SWR across 28-29MHz band From left to right is MHz, SWR, resistive impedance, reactive impedance, and overall impedance.

A word to the wise, DO NOT BE FOOLED BY SWR! A perfect 1:1 SWR does not mean that the antenna performs well or radiates efficiently. a 50 ohm resistor at the end of the coax with give a 1:1 SWR but I can guarantee that you will not contact anyone unless the sunspot cycle is incredibly active, there are stories of people making contacts on dummy loads... but you get my point!

The most important column is the reactive impedance (Xs) information. The Hustler 5BTV antenna is resonant when the reactive impedance is 0 ohms. The closer to 0 ohms the more efficient the antenna is at radiating the RF. Even if this value shows an SWR of >2:1. Yes, there will be loss in the coax due to the SWR mismatch but more of the RF getting to the antenna will be radiated.



A great explanation of this is on the ARRL TIS (Technical Information Service) article titled "Why an Antenna Radiates" written by By Kenneth Macleish, W7TX
in QST November 1992.

"Both kinds of resistance dissipate energy at a rate equal to the resistance times the square of the current. Of course, energy dissipated this way doesn't actually disappear. An alternating current, flowing against radiation resistance, turns electrical energy into radiant energy, which wings its way off into space. Current flowing against ohmic resistance transforms electrical energy into heat, which is mechanical vibration of the atoms of the conductor -- the atoms vibrate when they're hit by the moving free electrons"

I hope this post helps and provided a lot of information on the Hustler 5BTV antenna as well as a better understanding of antennas in general. While I haven't perfectly tuned the antenna yet its in "the ballpark"! Please let me know any comments or suggestions or if you have any questions!

Bryce
KB1LQC

Wednesday, July 29, 2009

CollegeARC.com

So what is my big project this summer? Is it all these antennas I am building? No. Is it the amplifiers I will be repairing? No. Actually, its a website! I am the Vice President of K2GXT the Rochester Institute of Technology Amateur Radio Club and have been a dedicated member since my first year at RIT. In high school I also founded the Chelmsford High School Amateur Radio Club KB1NAY which was awarded the ARRL Big Project grant. So I have been in several school clubs and have had a lot of experience not only being an active and productive member but also how one is formed and maintained.

My brother and I want to give back to the amateur radio community, we have been greatly appreciative of the support and generosity of the radio amateur. Our way of giving back has been to start a club and promote the hobby since we both got our licenses, but we want to give more. We are doing this by starting www.CollegeARC.com. This website is dedicated to providing a community to share the activities of college and university amateur radio clubs to the general public and radio amateurs. It even provides a way for prospective students or alumni to find out information regarding their universities club. It also serves as a way for clubs to interact, share ideas, and work together to build stronger member involvement and relations to the public.

We recognized that there are large swings of activity with college clubs, it happens. However, we feel that if there was a way to stirr excitement, share knowledge, and provide a community for clubs to grow a foundation on we can aleviate some of the problems. www.CollegeARC.com is a big step towards this and the more involvment we can get the better.

Both my brother and I have email over 40+ clubs but only 3 have responded and more than ten emails bounced back. We are feeling the effects of outdated contact information and old websites. So we have posted on the www.qrz.com news forum under the topic "CollegeARC.com Needs Your Help"about our goals for this project and asked for help just as I am doing here.

If anyone who reads this blog or stumbles upon it knows about amateur radio clubs at universities and colleges please comment or send and email! The website is not open to the public at this time, however it is planned to be launched in August just before the academic year. Thank you for reading this blog and post! I hope to hear from you!

Bryce
KB1LQC

Tuesday, July 28, 2009

Hustler 5BTV Antenna Completed

I finished my Hustler 5BTV (5 Band Trapped Vertical) antenna and here are some pictures to show it while testing and prior to burying the coaxial cable.

First off, here is the radial base which does not employ a radial base plate. I simply attached the radials to the base mount. The base of the antenna is 4" off the ground per the instructions from Newtronics/DX Engineering.


The radials fan out and fake the antenna into thinking the ground is more conductive than it really is. The more radials the better. I plan to eventually keep adding radials over time, some longer ones, maybe 1/4 wavelength at 80M over 180 degrees could happen, the other 180 is about 10 feet from my property line, so I'm not going to bother! Many small radials along the property line will do a lot better than the current zig-zag I have right now.

I wound a coaxial cable 1:1 choke balun with the RG-8 and a 6.5" paint can as a form (in the background). The manual asks for 6" but this is fine and its not critical to get exactly 6 inches. The balun simple stops any induced (from the energy being radiated by the antenna) RF traveling down the outside of the coaxial shield as there should be NONE, due to the skin effect it stays on the inside shield of the coaxial cable closest to the center. The balun DOES NOT inhibit the RF in the cable, only on the outside. I made sure it would keep its form, hence the duct tape, while the RG-8 provides enought stiffness with plenty of margine! I used wire ties going through a slit in the duct tape on the second, and second to last windings to provide strain relief for any tension on the coax.

Ok, the next picture is not really good I will appologize for the blurryness (I would love to own a Nikon D80 SLR after taking a non-photo major photo course at RIT... but my point and shoot has to do!). Using a borrowed MFJ-296 Antenna Analyzer I tested and tuned the antenna. The Hustler 5BTV requires that a choke balun be placed no more than 8 feet from the antenna AS WELL AS 8 feet from the transciever. If you do have one you MUST have both, they trap the RF on the outside shield to bounce between each balun, eventually attenuating (turning into heat). If the second is not used at the transmitter there will be a large SWR mismatch (>31:1 according to the MFJ-269). I wound a quick test balun with some spare coaxial cable. During this testing I identified the corroded adapter near the antenna feedpoint which was eventually replaced so that no adapter was needed. I also located myself as far as possible from the antenna while measuring to reduce any influence I may have on the antenna.

Lastly here is the final balun that is now used with the Yaesu FT-897 transciever on 80-10M in the radio room (shack!). I bought some high quality Belden RG-58 from my local independent electronics supplier, and its definitly nice stuff! It uses both a braid and foil for the outer shield and has a stranded center conductor (better flexing). Again, the paint can was used for a form and tape holds the windings together with wire ties at both ends for strain relief.


Results

No tuner is used ( I use mine in bypass mode) and the antenna is close to a 2:1 match on all bands! The bandwidth on 80M is only good for the phone band but its not the greatest resonater down that low either! I was up testing the transciever balun around 1 AM Sunday July 26, 2009 and heard several VK stations! That's Austrailia which I have rarely ever heard. What struck me as amazing was that I was on 20M (14 MHz) at 1:30AM listening to Austrailia. First off, most of the time 20 meters dies at night and while there was probably some great propagation that night as compared to normal, being able to clearly hear several station in VK land with such little background noise was amazing. The Hustler 5BTV definitly turned from a fancy aluminum rod shoved into the ground into a vertical antenna with a low takoff angle. The radial system is the difference between night and day!

I have linked to the audio recording of VK4MA that was heard on the Hustler 5BTV. Notice how little background noise there is considering my area of Massachusetts is relatively noisy. I switched to no antenna near the end but didn't edit it out of the recording.

Audio Recording at 1:30AM on the Hustler 5BTV hearing VK4MA on 14.260 MHZ

I hope this article provides enjoyment and some pointers. Feel free to contact me for any questions regarding this antenna or anything else on your mind! I have notice people tweeting some of my posts and really appreciate that others enjoy some of my projects and experiences! Thanks!

Bryce

Friday, July 24, 2009

40 Meter Pile-Up K2GXT

I operated K2GXT remotely through Ham Radio Deluxe to control the radio and Skype to pass the audio last night on July 23, 2009 starting around 7:30pm on 40 meters (7MHz). The station uses a Kenwood TS-2000 running about 100 watts into an off center fed dipole on top of the Student Alumni Union. More information about the club station and remote setup can be found at Brent's, KB1LQD, article Remote Controlled TS-2000.

I only planned on operating for 30 minutes or so but a huge pile-up formed on me while operating on 7.188 MHz. I ended up operating for about 2 hours and made 41 contacts as K2GXT the Rochester Institute of Technology Amateur Radio Club. I did not treat it as a contest and made a nice several minute conversation with each contact. The pile-up really tested the remote link and how it performed as well as my HF skills!

The log can be viewed online at this log analysis.

Monday, July 20, 2009

AO-51 Apollo 11 Special Event

So I stayed after work to catch the 6:20PM pass of AO-51 (Amateur OSCAR 51 "Echo") over Massachusetts on July 20, 2009. There is a really nice parking lot which is raised up a bit so with an Arrow satellite antenna I can hear AO-51 with ease from just under 10 degrees above the horizon. I was unaware that the control operator of AO-51 played a continuous recording through the satellite to celebrate the 40th anniversary of the Apollo 11 Mission.

The transmission starts with a clip from John F. Kennedy giving his famous speach of America's mission to go to the moon in 10 years "... not because it is easy, but because it is hard....". It then goes into 30 seconds or so of Niel Armstrong (I think...) stating that the engines of Eagle are off, a few seconds later "the Eagle has landed". Following this is mission control telling them that most of the people in mission controle are "blue" and can finally breath again! A Robot36 encoded SSTV transmission follows.

I tried to record it with my laptop microphone but something wasn't working and its a silent audio clip. Maybe some other bloggers heard these commemorative transmissions or even anyone who is interested please feel free to comment and let me know what you think or experienced!

Saturday, July 18, 2009

DX Engineering Hustler 5BTV Vertical Antenna


I have spent the last 3 weeks installing a ground radial system for my DX Engineering Hustler 5BTV 80M-10M (3.5MHz - 28MHz) vertical antenna. Opting for the marginal benefit of sixteen radials cut at the lowest frequency I plan to operate on. This means that each radial is thirty-three feet long! The picture to the left shows a view of the antenna and surrounding area. The two traffic cones are covering some horseshoe pit metal poles. They most likely affect the antenna but it's not the worst problem in the world!

Each radial is made of #14 wire I stripped out of three cable Romex house wire leftover from building our garage (yes we built it ourselves). I soldered ground lugs onto each end and attached them to the antenna base at the U-bolts since I do not have the radial plate.

Fanning each radial out about 22.5 degrees (just and estimate with the handy protractor), but I was not strict on the angles being exact or laying the radials exactly straight. Instead of digging trenches for each wire, simply taking a square shovel and making a long slit in the ground worked great and left minimal marks. I took a piece of scrap metal and shoved the cable down and followed with the shovel pressing the ground back into place.

It took me three weeks which consisted of about 20 hours in all of laying the wires. It could have gone much quicker but I had to get set up each time I went out to work on it because most of the time I would do this after work and only had a few hours of light. There is a compost pile right next to the antenna which I had to move for each radial, in the end the whole pile was turned over so I guess I "hit two birds with one stone". It hadn't been turn in a year or two so the tough and slow part was moving the wet flattened leaves.

Before I laid the radials for the Hustler 5BTV it performed like an aluminum rod stuck in the ground. It really didn't pick up signals well and was deaf by antenna standards. Any attempts to adjust the SWR were not easy, very touchy, and almost unable to be tuned below a 3:1 VSWR on the amateur bands. After putting these radials onto the antenna, I am able to adjust the elements as suggested by the manual with ease and so far have adjusted most bands to <1.9:1 VSWR. The picture to the right shows the base of the vertical a few days before I was finished installing the radials. The coax can also be seen which attaches under the antenna by simply splitting the sheath and center conductor appart. The Hustler 5BTV is mounted about 4 inches above the ground as suggested by the manual.

The Hustler 5BTV vertical antenna went from performing like a 21 foot aluminium rod stuck in the ground to a 80m-10m antenna! Using an MFJ 269 antenna analyser has been great and I hope to have SWR data and operating performance soon. The 4BTV is exactly the same except there is an extra trap and whip antenna attached to the top which makes the 5th band (80m).

Monday, July 13, 2009

I'm Back!

So its been almost a year since my last post, wow. To say the least, my second year at RIT a an Electrical Engineering major while also rowing for the crew team was INTENSE. I survived on about 3-4 hours of sleep 6 days a week September 2008 through May 2009 with the once or twice per week >2 hour nights (several times it was only 45 minutes). While not bad at once, do that for 9 months and yikes! I seriously thought I was going to have to quit the crew team but I somehow managed to stay on. I guess going through life with a positive attitude helps out! Well I guess its time to start documenting some more stuff on the blog and see if more traffic can come to it! Hopefully a bunch of projects will suffice, I have some good ones going on now and since I am currently on a 6 month Co-Op... I HAVE THE TIME TO DO PROJECTS!!!! Which also means no homework :).