Author Archives: Walter Underwood

Plastic Pipe Roof Antenna Support

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I noticed a clever antenna mount on another ham’s roof, so I built one myself. Putting my VHF/UHF antenna at the highest point of the roof has really improved my ability to copy some of the far-flung participants in our weekly ARES/RACES net.

plastic pipe antenna mount close-up

A cradle built from two-inch ABS DWV (drain, waste, and vent) pipe sits across the ridge of the roof. Legs two feet long go down on each side and a two-foot section is a vertical antenna mast.

My antenna is a Diamond X50NA, same as the X50A, but with a weatherproof Type N connector. I did additional weatherproofing with 3M Temflex 2155 rubber splicing tape and Scotch Super 33+ electrical tape.

I had spotted an antenna mounted like this and contacted the ham at that address. Rolf Klibo, N6NFI, replied with an article he’d written for the SPARK newsletter describing the mount. With that, I was off to the hardware store.

I used two-inch ABS DWV (drain, waste, and vent) pipe in two-foot sections. I cut up two of them to make the four pipe sections that go along the ridge of the roof.

The X50NA mounting hardware fits masts up to 2 3/8 inch, which is why I used two inch pipe. For coax strain relief, I used a conduit hanger that fit. Zip ties attach a loop of coax to the hanger so the full weight of the feed line isn’t pulling on the connector. That can rip the coax right out of the connector, or harder to diagnose, pull just one of the shield or center connector loose.

Antenna mount 3 Antenna mount 4

For a commercial version, I’d look at the Rohn NPPK, a steel frame that fits over the roof peak. It is designed to have a rubber mat underneath and four 18 pound concrete blocks holding it down. I’m sure it is far more secure than my DIY plastic pipe mount.

Allergy-Friendly Trail Recipes

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The cooking merit badge requires a Scout create menus “keeping in mind any special needs (such as food allergies)”, but doesn’t provide a source for allergy-friendly recipes. It does give a URL for FARE, but that doesn’t have an organized recipe section.

The next version of the merit badge pamphlet should reference Hiking Free: Allergy Friendly Recipes For The Outdoors because that is the only book I know of on the subject.

Hiking Free Kindle Cover

I’m not the right person to review it, because I don’t regularly have to deal with food allergies, but she created these recipes for her son’s food allergies. I’ll trust that. I do have several of Sarah Kirkconnell’s other books and recommend them highly.

The author describes it as:

110+ Recipes That Are Top 8 Allergen Free: No Gluten, Peanut, Tree Nuts, Soy, Seafood/Shellfish, Dairy & Egg. Recipes for backpacking, the great outdoors, camping, car trips, dorm living and travel, for anywhere you need easy to prep meals that are safe to eat.

You can buy it here, $12.99 for paperback, $7.99 for Kindle.

Also, the 2016 edition of the merit badge pamphlet keeps the dangerous trail cooking recipe that uses ground turkey breast. It just isn’t possible to safely store and transport that on the trail (see requirement 1c). I blogged that problem back in 2014 in the Cooking Merit Badge: Trail Cooking Fail post.

Update: Sarah has posted two of the recipes on her blog along with a longer story about how she came to create all the recipes.

Rig on a Board Update 1

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The “rig on a board” is working well. I’m a little worried about it scratching the central console, so the next version should have a cloth surface there. I’ll probably use a thinner board with some carpet or corduroy covering it.

Rig on a board 1

A wider board, maybe 10-12 inches, would leave plenty of room for the mic.

The wood for the prototype is 11/16 x 7 (measured), about 20 inches long, cut close to the middle. I used a regular door hinge. It has a little bit of play, but not too bad. A piano (continuous) hinge might be a better choice, especially if I use a wider board.

While I’m mounting things, an external speaker would help. I’ve plugged in one that I use with my Lowe HF-150 shortwave receiver and that improved the audio.

Hmm, 1/2 (or 5/8) x 12 (or 10) x 20 seems like a job for some scrap plywood. Just need to find some scrap carpet.

The Best Hot Pad

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I use what the professionals use, Tucker Burnguard hot pads. They are made of Nomex, with a vapor barrier, so they won’t melt and are less likely to cause steam burns when wet. They aren’t as flexible as other hot pads, so my wife doesn’t use them. But give them a try. If you like them, you are done with choosing hot pads for life.

Tucker burnguard 1

They aren’t exactly decorative and the label might burn, but the hot pad will protect you. And…it is about time to toss these in the laundry.

Oh, yeah, this is the Tucker Burnguard site. Here is a link to buy them at Chef’s Resource: Tucker 8″ Square Hot Pad with BurnGuard (Nomex)
. I’ve bought several things from Chef’s Resource, so I’m comfortable recommending them.

Rig on a Board Prototype

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This is a first cut at a removable mount for my VHF/UHF rig. Until now, the radio has been sitting on the passenger seat, but that is far from ideal. So I put together something simple that holds the rig steady and puts the display and controls at a better angle.

One end of the hinged board goes between the seat and the center console. The other end holds the radio. The power cable is dressed with a velcro tie behind the radio.

Rig on a board 4

I grabbed a scrap board (I think it is pre-painted house siding), sawed it into two chunks, installed a hinge in the middle, and mounted the radio bracket on one side. I screwed down a velcro cable wrap to keep the excess power cable from flopping around.

Rig on a board 2

So far, I like it a lot. I need to figure out a bracket to hang the hand mic, though.

Rig on a board 3

I’ll probably modify this a bit more before rebuilding it with a nicer piece of wood. I was thinking of securing it to the seat back with a strap, but it seems pretty secure as it is.

Using a Mobile Antenna as a Temporary Base Antenna

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For our July Fourth Safety Watch this year, I used my dual-band mobile antenna on a ground plane mount on a camera tripod. I’d purchased a Nagoya GPK-01 NMO Ground Plane Kit ($28) to test my NMO mobile antenna, because my mag mount seemed flaky.

As I was drifting off to sleep one night, I thought that the 1/4-20 screw on my camera tripod might fit the holes on the ground plane kit. It did, so now I have a robust, free-standing, dual-band antenna for em-comm use.

IMG 4753

The antenna is a Comet SBB-5NMO with 3 dB of gain on 2 m. Not a flamethrower, but a solid antenna when used with a good ground plane.

The radials unscrew from the mount, so the ground plane kit packs up small.

IMG 4750

Our station was up on a hill, so we had great line of sight to the whole valley. We ran a mobile rig (Yaesu FT-8900R) at 50 W from a battery, so we had a great signal. We could also hear the other stations clearly, so our station was net control.

IMG 4748

The only thing I’ll change next time is to use 1/4-20 wingnuts instead of regular nuts. I might paint them orange, too. I was sure that I would drop a nut in the grass and never find it.

And yes, that is a classic Gitzo Reporter aluminum tripod. If needed, I could extend the center column to get the radials above eye level.

Voile Ski Straps

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Better than bungee cords! I purchased a few of these, thinking they might work for strapping my fiberglass radio mast to posts and stuff. They are great. Stretchy, adjustable, and super easy to fasten and unfasten. After I tighten a strap, just releasing the tension almost always catches a hole on the buckle to secure it. Lovely design.

Here is one of the two I used to strap my mast to a railing on top of Mt. Umunhum for a SOTA activation. My shortest straps are red and 15 inches long.

Voile 1

Earlier, I used a longer blue one (20 inches) and two of the red ones, linked, to strap the same mast to a walkway post for ARRL Field Day.

Voile 2

A red strap held the balun to the top of the mast to take stress off the connectors.

Voile 3

I started with this variety pack of three sizes ($16.50 at Amazon), then stuck with the same color scheme for ordering more.

I’ll be taking these on every field radio outing. That means I’ll have swap them back and forth between my emcomm go bag and my SOTA gear. I think I can manage that.