Author Archives: Walter Underwood

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.

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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.

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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.

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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.

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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.

Bargain Ultralight: Mountainsmith Mountain Shelter LT

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Want to try a single-wall ultralight tent without spending a lot? How about the Mountainsmith Mountain Shelter LT, a two-person shelter that weighs less than two pounds for $100?

Mountain shelter lt 5

I used to recommend the Black Diamond Betamid for this, but BD stopped making it. Now Mountainsmith is making a very similar shelter. It sets up with two trekking poles, like a small circus tent. It is lighter than the Betamid, probably because Mountainsmith used silnylon instead of the urethane-coated ripstop in the BD shelter.

The Section Hiker review of the Mountain Shelter LT does a really good job of describing the tent. I’m seriously tempted to buy one, even though I have more than enough shelters.

The list price is $129 and it is available for a bit under $100. Links are from the Section Hiker blog.

This tent doesn’t have a floor, so you’ll need a groundsheet. My favorite thrifty and ultralight groundsheet is plastic window film. It costs five to ten dollars and weighs an ounce or two, depending on the size. For this tent, two one-person sheets might be good. Two popular products are Duck Brand and Frost King. I’ve never worn out one of these sheets, though I’ve been in danger of having them blow away. They are really, really light.

The Section Hiker blog has a nice article on ground sheets, including window film and Tyvek.

I wrote about my son’s experience with the Betamid at Philmont. He’s still fond of that tent. I hope a whole bunch of Scouts become fond of this one.

Whip Antenna Support for KX3

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A Nite Ize Gear Tie seems to do a decent job of supporting the MFJ-1820T 20 m whip antenna on my Elecraft KX3. I first tried forming it into a bipod, but then got the idea of attaching it to the SideKX endplates. Success!

KX3 gear tie 1

I’m using a Nite Ize Gear Tie 12 inch because I had one. The fatter one didn’t really fit through the handles.

The whole setup is pretty cheap. $25 for the antenna and $6 for two gear ties. It isn’t as efficient as a 20 m dipole, but it is kind of cute.