Saturday, June 27, 2015

Plans for an Arrow Antenna

Over on Bushcraft USA, another member linked to this PDF version of an article from the April 1992 issue of 73 Amateur Radio Today by KA0VFF and N0IMW on how to build a 2M Yagi antenna using aluminum tubing and aluminum arrow shafts for the elements. In the thread discussing it, the poster mentioned being able to check into a repeater on Greens Peak in AZ, from Flagstaff, a distance of about 150 miles using 50 watts. Pretty damn good, IMO. (The thread is here, but I think you need to be registered with BCUSA to view it.)

As a 4-element design, it should have a little more gain than my 3-element Yagi from Arrow Antennas. This will manifest itself only under extreme conditions, however.

With suitable weather sealing, it looks like this design would be a good choice for a permanent mount.

Finally, N5DUX's site has a good collection of ham-related PDFs. It's worth checking out.

Tuesday, June 23, 2015

Nifty Ham Radio Guides

An accessory that I find indispensable for all of my ham radios is the appropriate Nifty Ham Radio Operating Guide. The Nifty guides are produced on laminated paper. For the more complex rigs like my Icom 7200 and Yaesu FT-817ND, they are spiral bound. Those for the HTs are foldable cards. Each of them contains the most important functions of the radio in an easy to find format. They aren't as comprehensive as the OEM operator's manuals, but they are a worthwhile supplement, especially for field use.

Monday, June 22, 2015

The Other End of my 2M Yagi Test

As I mentioned in a comment to my original post on testing the Arrow Antenna 2M Yagi, I was able to have a QSO on 2M FM simplex with a friend using this rig. Distance was about 22 - 25 miles. 5W on my end, while he was using 50W into a Kenwood 2M mobile with a home Yagi on his end. (He would've lowered power but forgot how and didn't have his rig's manual handy.) Here's a pic of his setup, with a very post-apocalyptic vibe going on.



We also tried it with a Baofeng HT connected to his tape measure Yagi, but all I could hear was static when he called me, even though he was able to hear my 5W transmissions clearly. 

At some point I'd like to try 2M SSB, which should punch through better than FM, but don't currently know anyone else relatively nearby with a 2M SSB capable rig.

Sunday, June 21, 2015

A Ham Radio for SHTF Only?

My post yesterday, Testing the Arrow 146-BP3 Yagi Antenna, got picked up by a couple sites, including Sparks31 and Amateurradio.com. Thanks, guys! It also generated the following question:

Can you recommend a ham radio for emergency use only (hand held if available)?

There really isn't a good, quick, "Buy this radio," type answer.

Obviously, ham radios are a valuable addition to your preps, otherwise I wouldn't write about them so much. However, being able to effectively use a radio is more complicated than unboxing it, turning it on, speaking into the mic, and expecting someone to answer with useful information. You must learn something about radio operations and get some practice in before the SHTF. To do so, you must get licensed.

Piccolo summed up very well on Arfcom, here, why you need to get your ham license before the SHTF.

Getting a ham license is not hard for most people. Kids get licensed. Morse code is no longer required. The entry level Technician license requires you to pass a 35 question multiple choice test. This allows you to operate on VHF and UHF frequencies, which are good for local communications. The next level up, General class, gives you access to most of the HF (shortwave) frequencies, which depending on your setup, can give you regional to global communication capabilities. This is a second 35 question exam. There's a lot of overlap in the two exams, so it's not uncommon for someone to pass the Technician exam and then take and pass the General exam in one sitting, for one $14 fee.

The American Radio Relay League has info on how to get licensed, here.

After you've read some of the Technician level study material you'll have a better idea of the capabilities you need/want in your commo gear.

Now, if I've convinced you of the need to get licensed, I'll mention that no license is required to purchase a ham radio, and you can listen as much as you want. Just don't key the transmitter until you're licensed.

Saturday, June 20, 2015

Testing the Arrow 146-3BP 2M Yagi Antenna

I tested out the Arrow 2M Yagi antenna that I got a couple weeks ago, by hitting the Pottstown repeater on 2.5 watts from my yard. The repeater is about 25 to 20 miles away. I spoke to another ham who said I had some background noise but was intelligible.





To attach the antenna to the camera tripod, I made an adapter from a piece of 5/8" aluminum rod. I turned one end down to fit into the antenna boom, and then drilled and tapped a 1/4"x20 hole in the other end.


There's about 2" of rod in the antenna boom, while there's about 1/2" of engagement with the mounting screw on the tripod head. This is a temporary, light duty setup, but it's easily portable.


Tuesday, June 16, 2015

Stanley Cooker and Nesting cups

A couple years ago on Bushcraft USA I first read about the Stanley Cooker and Nesting Cups set. A few months ago I was at Target with my daughter and saw that they had them in the camping department, and each bought a set. Cost was $14.95 each, plus PA's 6% sales tax.

The cookset consists of a 24 oz. stainless steel billy pot with a lid, a handle that folds over the top when not in use, and two plastic cups that fit inside the pot. The billy handle locks in place and if you keep it out of the flames stays cool to the touch.


The billy has fluid measurements stamped on one side for 8 oz./237 ml, 12 oz./355 ml, 16 oz./473 ml, and 20 oz./591 ml. This will be handy for boiling water for dehydrated meals.

The diameter at the top is about 3.75" and it's about 6" tall. After a couple inches it steps down in diameter to approximately the same outside diameter as a 32 oz. Nalgene bottle. One side of the lid has one vent hole while the other has six. You could use these to strain out water if you've cooked something like noodles in the pot.

The lid's handle is a folding plastic tab. If you will only use the pot on top of a stove this will work OK and it stays cool to the touch. However, if you're going to put the pot in a fire it'll burn off. (There are pics of this on BCUSA.) So, I removed the plastic handle with a set of dikes and replaced them with stainless steel split rings.

The original handle and now the split rings are held to the lid with a strip of stainless steel that is spot welded to the lid. Unfortunately, each end of the strip is held with three tiny spot welds. I managed to break the welds on one end of the strip on my set, so I'll need to reattach it with either a rivet or stainless steel nut and screw. Keep this weakness in mind if you plan to suspend the set by the ring. (You can lock the lid on with the handle and hang the whole thing over a fire from the split ring.)

Aside from this one shortcoming the set is very well made, especially for under $20 retail.

The two plastic cups each have a line inside near the top, which marks where 8 oz. of fluid reaches to. I like the cups. We used a set to boil water for hot chocolate and the cups were comfortable to hold with the hot liquid. A few guys on BCUSA don't care for the cups and said that it made their drinks taste like plastic, but I did not notice this. The Stanley pot will nest inside a GSI Space Saver cup, as commonly used with a Nalgene bottle. Combining the two gives you more flexibility in your cooking and eating arrangements.

As seen in various threads on BCUSA, if you take out at least one cup you can store a folding butane canister stove and small fuel canister inside the billy bot. Or, if you keep both cups, there is still plenty of room for food or drink you can prepare with this set, such as tea bags, bullion cubes, or oatmeal packets.

One thing to be aware of is that because of its shape (tall and narrow) it will take longer to boil an equivalent amount of water than a pot that is short and fat, if you're heating it from the bottom. Less surface area on the bottom means that there's less surface area to absorb heat from your heat source. However, if you put the billy in a fire, e.g., next to burning wood, the tall/narrow shape may actually allow it to absorb heat faster. This shape may also fit in some backpack pockets better than a short/fat pot.

The one real downside of this pot is that if you have large hands it may be difficult to reach into the pot and clean the bottom well. In that case you may want to use it just for boiling water or get something else.


Baofeng Battery Test Results

Over on amateurradio15.com (home of the Fo Time! podcast), the results of battery life tests for Baofeng BF-F8HP performed by one of the listeners is posted. This is good info both for that model of Baofeng radio, but also to compare different batteries.

Check it out.

Sunday, June 07, 2015

A Little More Backyard Digital Work

I played around with the FT-817ND and digital some more today. I wanted to try my 20M MFJ-1620T hamstick antenna with the same base as my telescoping vertical. I figure that the hamstick would be good for situations where you need to be a little stealthier, or need to set it up more quickly. The hamstick is about 7' tall, in contrast to my MFJ-1979 telescoping whip, which is about 17' tall.

However, I got the high SWR warning on the rig when I transmitted. So, if I want to use it I'll need to tweak it some to reduce SWR, or use my LDG Z-817H tuner.

It's very difficult to get a clear picture of the hamstick when deployed in my yard. It blends very well into the background. Note that the antenna is nowhere near the power lines in the background.



Even with the high SWR and low power, my PSK31 signal got out as far west as Missouri and as far south as Florida.


I changed over to the MFJ-1979 telescoping vertical whip, which gives better performance and lower SWR.

Transmitting PSK31 on 20M using 5 watts, my signal was heard 2285 miles away in Washington state, and ~2100 miles away in Venezuela. I didn't have QSOs with those guys, but their PSK software uploaded the reception reports to pskreporter.info.


Pretty decent for QRP, IMHO.