Shack in a Can … a 25mm ammo can

Shack in a Can. It’s a ham radio thing.

(VIDEO at the bottom)

Dan Passaro 25mm Ham Radio GoBox

Dan Passaro Ham Radio gobox-8633

The ‘shack’ is the place where an Amateur Radio operator sets up their radio gear. A spare bedroom, a structure in the backyard, inside the roll-up desk in the corner of the living room, whatever.

In this case I put all the gear necessary for making contacts inside a can, a 25mm ammo can, which, naturally, holds 25mm ammo. Cannon shells specifically. Numbers on the can: Part No: 12013854, Container Assy No: 12013870, Container and Ammo: 12013668

Of course it now holds the key to talking around the world.

Usually all you need to make contacts is the transceiver (radio) with connections for antenna and power.

In this case I put the radio and the power, a battery, in the same container. Then I ran the antenna connection, aka ‘jumper’, from the back of the radio forward to a 3D printed panel I designed in Solidworks CAD. This panel had a voltage display to show me the state of charge for the battery along with some 12V outputs and the aforementioned connector for the jumper.

Here is it’s construction.

Everything began with the radio. The more the radio itself featured, the fewer external components that would need to be dealt with.

The first thing I’d noticed about HF transceivers is that they always seemed to have some external tuner connected. My goal then became finding a transceiver with an internal tuner.

Then I’d noticed that rigs loved amps. The second goal became finding a transceiver that sipped the amps instead of chugging them.

Then overall size. I needed a rig that was compact and wasn’t so heavy as to be an anchor for an aircraft carrier.

Seems like a tall order right?

There are certainly a variety of options out there but personally I whittled them down to:

Yaesu 857D, Yaesu 817ND, Elecraft KX3, and the ICOM IC-703 Plus.

The 857D had the power but at low output settings still sucked amps and it didn’t come with a tuner. The 817D is a neat compact rig, had the power sipping requirement but no tuner and it was only 5W output. That explained why most online videos show this rig being operated using CW.
The Elecraft KX3 had it all … plus a price tag. So unfortunately that was out.

Enter the 703 Plus, a discontinued rig. I had to go there lol. It too had it all. The only thing that would make this rig perfect (as well as the KX3) is 25-30W output.

Not 100W? Nah, then you really lose the power sipping requirement that you need in a portable. 25-30W seemed like the best compromise.
But alas both the KX3 and the 703 Plus had 10W output. Three amp draw on the 703 Plus and a little less even for the KX3.

That’s ok. Antenna, antenna, antenna.

Just a reminder … we’re going for compact here.

That meant wire. There seem to be more wire antenna options than rigs so let me skip to the end and tell you that I went with the EARC end fed wire with it’s 9:1 UNUN setup. Their website also supplies instructions for making your own. I chose to support the club and placed the order.

From Miami, FL I’ve QSO’d with Argentina and Eastern Europe on 10w with that end fed wire.

So we had the radio and the antenna. Now we needed power. A simple matter of choosing an SLA right?

Not yet. First we had to choose our container and then see which SLA would fit inside along with the radio.

Enter the polymer 25mm ammo can. Polymer so it wouldn’t rust and it wouldn’t cause undue damage to whatever surface it was placed on. Both the front and the back opened up (not such a big deal if you were to simply create a pull out rack) and watertight.

MOST importantly though … it looked cool. Priorities.

A few labels made up in Photoshop and presto, I had an Official Communications Setup (c).

So which battery would fit in that box? The typical SLA design meant that the largest I could fit in the box, along with the 703 Plus, was a 9Ah battery. Owing to the choice of rig that meant sufficient power for a full day’s casual operation.

To keep everything clean I designed the control panel section to house a Double Pole / Double Throw / Center Off switch, voltage displays, inputs/outputs and antenna connection.

I wanted everything to come out the front of the box to avoid opening the back.

I used a piece of stiff cardboard as a mockup, cutting out the pertinent areas to iron out the ergonomics.

With the lessons learned from that, and component measurements taken with my reloading calipers, I built a model in CAD that I subsequently had 3D printed.

A week later it was ready for install.

My wiring design is different from most in that I have two Anderson PowerPole inputs and two voltage displays (then one triple set of APP outputs, such as to charge an iPad).

The overall wiring design revolves around the DPDT switch.

One direction of the DPDT switch uses the internal battery to power the radio and the APP outputs.

The other direction cuts the internal battery off from the circuit and engages the external power input to run the radio and APP outputs.

Why did I do it that way? The intent for the box was portable operation which to me meant solar power and that meant moderate charging power.

By isolating the internal battery I could channel all that solar power into charging that internal while running off an external. The dedicated display would let me see the state of charge. Naturally I could also charge and run at the same time if I so chose, essentially solar floating the battery.

I also had a 35ah SLA in a separate box but due to the continuous clear skies I was able to solar float the internal all three days of my DXpedition.

As you’ve guessed, everything in the control panel is back-secured for a nice clean appearance and the state of either power source is readily visible. The three screws attach the panel to a block that is secured to the box. This way I can easily remove the panel to get to the wiring if necessary.

Again, unlike most people, I have only the radio leads fused.

I went with the Morningstar SG-4 Pulse Width Modulation solar charge controller and a folding solar panel.

The PWM algorithm wouldn’t be fooled into bulk charge mode by the transient keying and unkeying of the transceiver.

The panel was the Instapark Mercury 27, a 27w panel the size of a thick notebook when folded.

Still I ran out of room inside the box so the solar panel travels outside.

Back to the radio. The radio is held in place by two pieces of bent, 1in wide, 1/8in thick aluminum from the local big box construction store with the bottom of the radio resting on the battery.

With the lid closed the radio remains in place. With the lid open I’m able to slide the radio out. Besides, I could always just open the back lid.

Originally I’d tried to Velcro the aluminum to the box, which worked ok … for a while. Then I tried the much vaunted double sided acrylic tape from 3M (think GoPro sticky stuff) but that soon also unstuck.

I couldn’t drill into the box, I’d compromise the watertight nature even if I used rubber washers.

And, again, MOST importantly … it would look ugly. Priorities.

Epoxy didn’t stick either. So there I was, still trying to come up with a way to attach the aluminum.

Two days later it hit me … 3M Fast Cure 5200. It had been a while since using that stuff so I had forgotten about it but it would be perfect. The power of epoxy with some slight flexibility but now with sticking power.

The ‘stand’ is the remaining portion of the aluminum secured to a hinge which is then secured to the box, again using 5200. Just a leaning post really, as you can see in the pictures.

We have the radio held in place, control panel to it’s left. Under the forward part of the radio is my headset and homebrew Push-To-Talk switch built off a Cat5 cable. In the lid I placed several dots of Velcro. To this I attached a band-less digital watch set to UTC, a small AAA flashlight, and a pencil.

Open the back lid and we have the 9ah battery, 33 feet of antenna wire, 9:1 UNUN and 16ft of SO-239 terminated RG-8x coax under the rear part of the radio.

Yep, it all fits.

On a DXpedition to Fort Jefferson on Garden Key in Dry Tortugas, in addition to the end fed, I brought a mast supported antenna that I could configure as a 20m 1/4 wave vertical or as a 6m yagi. I knew from my research of the location that I couldn’t attach anything (at all) to the trees or foliage down there so a mast would be required. Plus there was nothing on the North Coaling Dock to attach to anyway.

So there it was, everything nice and secure, a control panel where I could plug and unplug items and leave the box in position, a strong case that I could cinch down with ratchet straps, and watertight in case a rain storm came upon me.

Worry free and it added up to a 24lb shack in a can that was, best of all, easily transported.

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Essentials for your laptop bag

I have three basic groups I carry in my laptop bag; aka My Writing Kit:

Dell 3531 Laptop in its cocoon

Dell 3531 Laptop in its cocoon

1. Computer Group.
The laptop, THIS ONE, and the wall charger. I do plan on adding a spare battery.

2. File Group.
Literally files and perhaps a notebook.

3. Goodies Group.
This is the group we’ll focus on here.

So what does the well stocked laptop bag hold within it’s Goodies Group?
The Comfort Kit.
The Charger Kit.
The Food and Drink Kit.

In the Comfort Kit we have:
* Flents ear plugs, purple. 33db noise reduction on these babies.
* One of those thin fleece caps, for those really cold coffee shops lol. A regular baseball cap should hold in enough heat.
* Nose drops, Afrin regular. Much better than desiccating yourself with allergy pills or the like.
* Pack of tissues.
* Headphones. I just have the latest Apple earbuds and figured out how to (re)pack them in that case they come in.
* First Aid kit. Just a little pocket one which has Ibuprofen and a band-aid. Basically one of THESE, plus one or two Alka-Seltzer Plus in Citrus. I think the Cold and Cough version. I just use it in case of over-eating lol.
* A new blush brush. Yep, you read that right. I use it to clean off the keyboard and the screen.
* A Swiss Army Knife, like the Classic, is useful. Jut remember it’s there when flying. I have a SAK Bantam on my keychain.

The Charger Kit:
* Laptop charger
* Portable battery pack with USB out, at least 1 amp. I still have an Eneloop KBC-L2 pack rated at 5,000mAH. It’s roughly the size of a deck of cards.
* USB cable for iPhone
* Wall charger for iPhone. Naturally it will charge through any USB cable.

The Food and Drink Kit:
Just one or two 16oz water bottle and one or two food bars or Snickers. I also sometimes use a 16oz Pilot’s Flask since they are flat-ish and easier to pack.

It all fits into a Targus laptop bag most similar to THIS ONE. This is the only bag I have right now that accommodates this laptop (the Dell is a full 15 inches wide) and as you can see the interior pockets are empty. I don’t want anything to scratch up the laptop or crack the lid.

Not the perfect bag which is why I’m looking at the Netpack Comp Brief I and the Solo Urban 17 :D

Front flap stuff (and things) in the laptop bag

Front flap stuff (and things) in the laptop bag

Some of the laptop bag  goodies laid out

Some of the laptop bag goodies laid out


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Filed under Electronics, General, Writing

My Dry Tortugas article has been published

Article header, QST Magazine, March 2015

Article header, QST Magazine, March 2015

Alright :D

Here is a PDF link to the draft version: QST Dry Tortugas article

Three months of prep to get over to Dry Tortugas; specifically Garden Key, home of Fort Jefferson.

My view from the bow of the ferry on approach to Fort Jefferson on Garden Key, Dry Tortugas

My view from the bow of the ferry on approach to Fort Jefferson on Garden Key, Dry Tortugas

Fun fact:
I wrote the article BEFORE heading over. :D
I used it to create my plan of action in getting to the Key, setting up and operating my ham radio station and developing goals for each day.
Then I edited the article accordingly. I was about 90% on with my article. :D


Posing next to the 1/4 wave vertical antenna on the North Coaling Docks at Fort Jefferson, Garden Key, Dry Tortugas

Posing next to the 1/4 wave vertical antenna on the North Coaling Docks at Fort Jefferson, Garden Key, Dry Tortugas

Posing at the entrance to Fort Jefferson on Garden Key in Dry Tortugas

Posing at the entrance to Fort Jefferson on Garden Key in Dry Tortugas

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The One Thing I truly despise about my iPhone

It’s just the one, I promise. My Blackberry 8310 had this as well.

The thing that bothers me so much about it on the iPhone though, like my 6 Plus, is due to the way I use the iPhone.

iPhone 6 Plus Dan Passaro

So you’re there on your phone: composing an email, prepping a tweet, editing a photo, taking video … and a text message comes in.

What happens?

Not much. The banner comes down with a preview of the text. Then it goes away.


Same thing with email alerts, app alerts, etc.

No. Big. Deal.

But if the phone rings?


Video gets killed, edits lost on a photo, etc.

I’ve had the iphone since the 3. I still get furious when the ******** thing goes off in my face.

“Well dude, it’s called an i’PHONE’ dude.”

Yeah, but it’s not ‘just’ a phone quite frankly. It never was. The iPhone was always a multi-function tool.

With the Blackberry it wasn’t bad.

What I don’t understand is why the damn iPhone phone function can’t just give a half screen dropdown with the number/label and Decline/Accept right underneath WITHOUT nuking the app you were in.

It really does irritate the hell out of me lol.

Ok, rant off :D


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Four tips to get your writing done at Starbucks

My Dell 3531 laptop pulling it's weight at Starbucks

My Dell 3531 laptop pulling it’s weight at Starbucks

Items Needed:

1. The right Starbucks
(or, of course, similar coffee shop)

2. Writing tool
(laptop, tablet, perhaps with external keyboard, maybe a phone, which I’ve done)

3. Earplugs
(or headphones, we’ll touch on that)

4. Internet connection


1. The right Starbucks
What you’re looking for is a location that has a big table. For example, the Starbucks at 8442 SW 8th St, 33144 has three options: the big high school lunchroom type table, the glorified TV dinner tray tables in the back, and the single seat sofa seats with small end tables around them.

The big table is where you can lay stuff out, and still not bother those around you.

Another Starbucks nearby, on US1, has the same three options. Their table is raised up high and you sit on bar stools. Also works great.

2. Writing tool
I use a laptop. Make sure you get one with long battery life, or, at least, four hours. I got myself a Dell (Dell 3531 Review). For a while I used an iPad Mini while sitting in one of the sofa seats. Doable, but a keyboard separate from a screen is moh bettah.
Same with handwriting, better on a table surface.

3. Earplugs
I use the purple Flents plugs from Walmart, the big tub, about 40 pairs. They are 33db nose reduction and the exact thing I use when competition shooting. Unobtrusive and they allow for a proper cheekweld. Since I have them I use them in the coffee shop.
Every Starbucks, every coffee shop I’ve been to in fact, has music going about two steps louder than necessary. Plus there’s that milk steamer, WRRRRRRRAAAAAAAAGGGGHHHHHHH, going off.
Earbud headphones don’t provide the isolation you need, plus there you are listening to something anyway.
If you’re going to do headphones, get the over-the-ear noise-cancellation type and then you can listen to your stuff at low level and still drown out the surrounding noise.

4. Internet connection
Yes, I put this last. You’re here to write after all. But it’s nice to have the option. Every Starbucks I’ve been to has free wifi. It’s just enough speed to look stuff up, do a quick tweet, write online directly (such as for a blog) and work from an online copy of your stuff.
I use dropbox and I’m currently transitioning to OneDrive. Either one will allow you to work offline. Just make sure you synced first when you did have internet. With Windows 8, and probably Windows 10, make sure you set OneDrive to allow you to Use Files Offline. OneDrive is automatically set that way with Windows 7.
Even so I make sure my phone has the hot spot option (or get one of those dedicated hot spot pucks). In my case I have an iPhone 6 Plus that handles the hot spot option, if necessary.

Two Bonus Tips
* Use ONLY enough bag to carry your stuff. Anything larger only encourages you to carry MORE than you need.

* Have some goodies with you.
Examples include:
* An extra (charged *cough*) laptop battery. I also carry the wall charger thing but I don’t count on an outlet being available.
* A battery pack with 1Amp USB out for your phone along with the appropriate USB charging cable.
* A Swiss Army knife. Get the model with the toothpick and the tweezers. That’s nearly every one of them. I use a Bantam on my keychain. A good all around one is the Classic and then there are the models with the Philips screwdriver. Just remember it’s there when flying lol.
* A water bottle (I use a 16oz pilot’s flask because it is flat). Just watch out when flying, the whole TSA thing again.
* A food bar (even Snickers will do).
* Nose drops. I use the plain Afrin. This way you don’t mummify yourself with pills.
* Tissue pack. Naturally you can use napkins, which I did a moment ago :D
* A blush brush. WHAT?! Yep, a new, never used, blush brush. I use it to wipe off the keyboard and the screen. I have one that came in a snap sleeve. What can I say, I’m a practical man. I also buy those wooden sticks chicks use for their nails. They make great gun cleaning tools, to get into the nooks and crannies. :D
* A hat. Sometimes these coffee shops, in addition to having the music too loud, have the A/C too cold. It’s a business after all, they want churn. (ok, alright, it’s all relative)
Since so much heat escapes from your head you can offset this business practice and focus on your writing. A baseball cap will do (it’s not Arctic cold lol) or one of those thin fleece caps.

Of course, you can just get another hot beverage :D

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