Category Archives: B’s Blog

6M Yagi Match

Taken with SmugShot on my iPhone

Last year for Field Day I built a 6 meter, 4-element Yagi-Uda antenna for the W5YA team.  I never tried to match the antenna for 50Ω, and it compared poorly to Doc’s Hex Beam antenna.  This weekend, in anticipation of FD 2014, I decided to finally try and match the antenna.  I tried several designs.  My initial try was a hairpin match, which brought the 100Ω impedance up to 200Ω.  Then, I tried a 75Ω, 1/2 wavelength coax transformer as a 4:1 Balun.  I played with this a lot, but could not get it to match well enough.

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Today I tried a parallel 75Ω match based on this page.  Based on my Yagi dimensions, this showed a resonant frequency around 48 MHz.  I shortened my driven element whips about 2″ and brought the antenna to a perfect (enough) match!



KD1JV MTR v2 Part 1

I’ve been slowly building up my Steve Weber Mountain Top Radio version 2 kit over the past week. For the SMT parts I chose to try reflow soldering in a toaster oven, and I’m glad I did it that way. I used solder paste in a syringe from Cash Olsen as recommended by Steve. For the oven I used an unmodified $20 Rival oven from Walmart set to 420F and simply watched for the paste to become glossy solder.

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Once the SMT parts were in place, it was easy to finish the standard through hole parts.

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Right now I’m in the process of winding the toroids and soldering them down. I’ll update this again once all parts are down and I begin with adjustments and testing.

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New Buddipole mini shockcord whip

Buddipole finally released a mini version of their adjustable shockcord whip, and today I got to test it with Wayne KD0VPR and his recently finished Bit20X transceiver. We made one contact from CO to NH but conditions were tough with a contest going on.

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We had the Buddipole set up as a vertical, with 4 of the 11″ arms and the 9 section whip fully extended. We only needed 1.5 turns on the coil to make up for the slightly short 1/4 wave. Two opposing elevated radial wires were about 17′ each and dropped from the versatee at 8′ to about 2′ above ground at the ends. We made two more contacts, both to NH, from the same setup but 100w and an FT-450.

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For anyone considering an adjustable whip, I would recommend this over the longer version, unless you go up to the 32″ one. The pricing needs to be updated for the 24″ version as it costs more right now than the 11″ version!

Feedburner active!

Ok, it took me a little while, but I finally have the feedburner plugin activated and working. Feel free to subscribe using the link in the sidebar.
Bryan N0BCB

Buddipole 2m 5/8 wave vertical

I’ve been doing some searches for a 2 meter, 5/8 wave vertical using Buddipole parts, and so far I haven’t come up with one. So, I decided to figure it out on my own! This is pretty easy to build if you have the Versatee and rotating arm kit. I only had 2 whips available, but with 3 and a jumper you could use 2 ground planes.
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This antenna is tuned around 146.52 as a center frequency. Adjusting the element lengths and/or the coil taps should allow use over the whole amateur band

Freqency

SWR

R

X

145.0

1.4:1

44

17

146.0

1.1:1

45

4

147.0

1.3:1

63

10

A closeup of the Versatee.  Connect the Red coax wire to the Blue Versatee connection.  Connect the Black coax wire to the Black versatee connection.  The Coil wander lead connects to the coil 1.5 turns in from the brass screw at the top of the Coil. This should equate to ~ 0.15 uH of inductance.

MFJ-259b at 146.52

Ground plane element length (19.25″):

Vertical element length (48.0″):

Mini coil tap (1.5 turns in from the top, brass screw)

Gram and Grampa Bibeau remember

I captured this audio clip while drinking coffee with my Grandma Nancy and Grandpa Paul Bibeau on September 20, 2012 and thought other family members might enjoy it.

5BTV radial wire system

I put together a radial system for my 5 band trapped vertical antenna. I’m using (32) 16.25′ radials, soldered to a 10 gauge bare copper wire. The copper ring will connect to the 3 bolts at the base of the vertical. For wire, I purchased a 500′ roll of underground dog fence wire at Home Depot. Each wire will be buried just below the surface in a star burst pattern. I used the ARRL antenna book to calculate the optimal radial system for the amount of wire I have.

5BTV radial wire

5BTV radial wire

Blue Sky Marathon 2013

Erin and I helped with the Indian Summer North aid station at the Blue Sky Marathon for our 4th consecutive year on Sunday.  Erin was the race photographer, and I helped with radio communications.  It was a fun day, with great weather.  I made a time-lapse movie that covers roughly 7am to 1pm, looking West from our aid station.

 

Homemade shock cord whip Part 1

I decided to try making my own shock corded whips for my Buddipole system. There are a couple of good reasons to do this. So far I’ve purchased all parts at 13″ or less to keep the Buddipole good for travel. The Buddipole whips look nice, but they’re 22″ long and are expensive.
For about $50 shipped from quest outfitters in Florida, I purchased (18) 13″ Easton 0.340″ tent poles. My plan is to machine brass adapters for a tight slip fit between sections, and a 3/8-24 brass adapter for the versatee. All parts will be held together with 1/8″ shockcord. This will give me a set that can be used as a dipole, or as a vertical with my RAK. More updates once I start turning metal!

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2013 North American Summits on the Air Weekend

September 7th & 8th is the annual SOTA Activity Weekend

North America SOTA Activity Weekend is a casual event involving tiny battery-powered radios on mountain summits.  It is not a contest but is intended to introduce “Summits on the Air” to newcomers with home stations who try to work summit operators during one or two days. There are no rules regarding power levels, modes or number of bands worked, but please be courteous when more than one station is trying to talk to a SOTA operator on a summit.  The SOTA operators have just climbed mountains as high as 14,000 feet; they use low power; and they don’t receive on split frequencies.

Check SOTAWATCH.org to spot who is on which mountain.  Summits are numbered, and you can hover your cursor over the number to see the name and point value for each summit.  Expect that website to show activity near 7.032, 7.185, 10.110, 14.342, 18.095, 18.155, 21.350, 24.905, 24.155, 28.420, 146.52, 446.00, and 61 Khz up from the bottom of 20, 15 and 10 meters CW.  Participants are invited to collect points toward certificates and trophies offered by the eleven-year-old international SOTA group (SOTA.org.UK).  As we learned in past years, this is a barrel of fun for both hill climbers and home operators.  See you then.