Wednesday, August 27, 2014

Software Defined Radio

As explained in Wikipedia:

Software-defined radio (SDR) is a radio communication system where components that have been typically implemented in hardware (e.g. mixers, filters, amplifiers, modulators/demodulators, detectors, etc.) are instead implemented by means of software on a personal computer or embedded system.

Traditionally, SDR has been an expensive endeavor. However, some clever hackers discovered that some very cheap TV tuner USB dongles based on the RTL2832U chip can be used as wide range radio receivers.

Back on August 9th I ordered one of these RTL2832U-based USB TV tuner dongles from Amazon for $8 and change. It shipped from China and arrived today. I then downloaded and installed SDR# using this quick start guide. So far, I just have it receiving FM broadcast signals. Here’s what it looks like tuned to the local classic rock station:


As described by Sparks, this $8 dongle can be used as an RF spectrum analyzer to discover what signals are in your area. This cheap piece of hardware plus some free software, and a laptop, Raspberry Pi, or BeagleBone Black system can be used as a portable, low-cost signals intelligence gathering system.

Tuesday, August 26, 2014

Using Fldigi on a Mac to Control an Icom 7200

Ray, W3PRR, asked me for help on configuring Fldigi running on a Mac with OS 10.9.4 so that it can control an Icom 7200 radio. Here’s how I did it:

1. Get yourself a plain USB-A to USB-B cable, as used with most recent computer printers. This one at Amazon will work fine. The IC7200 has a built in sound card, and the USB cable will provide both rig control and audio input/output through the one cable.

2. Make sure the OS is up to date by running OS X’s Software Update.

3. You need to install the driver for the Silicon Labs CP210 USB-to-UART bridge, which is what provides the brains for the USB-B port on the back of the radio. You can download that here.

Note: Do not connect the radio to your Mac when you install the driver. Connect the radio after you install and reboot the Mac.

4. Download and install the Hamlib radio control libraries.

5. Download and install the latest version of Fldigi.

6. Connect and power on the radio to your computer using the USB cable. Make sure that the radio is in Data mode, and make sure that Data mode is set to U, so that it accepts audio and CAT commands through the USB port. See page 43 of the Icom 7200 Instruction Manual for details.

7.In Fldigi, under Configuration > Audio > Devices, select PortAudio, then USB Audio CODEC for both Capture and Playback. Click Save before you move to the next step.

Note: If the radio is not connected and powered on, the USB Audio CODEC option will not be visible.

8. Under Configuration > Rig use these settings.

Click Initialize, then Save, then Close.

At this point you should be able to see activity in the Fldigi waterfall (ASSuming there is anyone on frequency), and you should be able to transmit from within the program. The 20M PSK31 calling frequncy, 14.070 MHz, is a good frequency to use for testing because it tends to be active.

Sunday, August 24, 2014

Mora Knives

The best bang for your buck in a survival knife is any one of the variations of the Swedish Mora. I have several floating around here, including two carbon steel Mora Clippers that I got from Amazon last week. One of them was bought specifically for use in the kitchen, while the other one is for garden and field use.

This pic shows one of the Mora Clippers along with my Cloudberry Market puukko that has become my primary field knife.

Both knives came with right handed sheaths. Since I’m a lefty, I made a new sheath for the puukko, and modded the Mora sheath. To do so, I used a Dremel cutoff wheel to remove the belt loop, then made a new loop on the other side of the sheath with a piece of nylon webbing, and secured it to the plastic sheath with Gorilla tape.

The two new Moras came shaving sharp. So far I’ve used one to cut up peppers in the kitchen, and the one shown above for cutting up a bunch of over ripe cauliflower that went into my compost bin. The cauliflower is responsible for the discoloration. Something in it immediately caused some oxidation, but the edge was unaffected.

It’s been my experience while camping and (back in the 80s) being involved in SAR missions that you can handle most of your cutting needs in temperate climes with a knife about this size. It’s no chopper, but if you need to chop things you’re much better off with an axe or hatchet, and a small folding saw is better yet.

Is a Mora the be-all, end-all survival knife? No. Something like my puukko is better made and has a slightly thicker, stronger blade. That said, the Mora Clippers currently sell for $13.92 on Amazon Prime. At that price you can afford to acquire multiples and stash them all over.

Aside from Amazon, another great source of the Mora knives, as well as some much nicer Nordic cutlery, is Ragnar’s Ragweed Forge. I’ve ordered other Moras and a nice puukko from Ragnar and always had a smooth transaction with quick delivery.

Near-Miss by Carrington-Class CME in 2012

You may have seen recently in the news stories about a coronal mass ejection (CME) that narrowly missed the Earth in 2012. It apparently was at least as big as the CME which caused the Carrington Event in 1859, the largest CME on record, and twice as strong as the CME that caused massive power outages in Quebec in 1989.

NASA has also provided a nice video explaining the storm:

Carrington-class CME narrowly misses Earth

According to the NASA article, there’s a 12% chance that we could experience another bit hit in the next decade. (Or if you prefer a more optimistic view, there’s an 88% chance it won’t happen.)

If we’d been hit by the 2012 Solar Storm, the damage would have been far more severe than some fires started at telegraph stations. It’s likely that extensive sections of the power grid would have been brought down and we’d still be recovering from the hit. This would be a true TEOTWAWKI event. Unfortunately, this is the kind of thing that’s really difficult to prep for, unless you’re Amish.

How to Install Anderson Powerpoles

The last time I took my Icom 7200 to the field one of the Anderson Powerpoles on the end of its power cord came off. I had a spare power cable that I swapped in after I returned home, and this afternoon I fixed the old one.

PowerWerx has a nice illustrated guide  showing you how to install them, here. Both PowerWerx and Quick Silver Radio are good sources for powerpole related items including the powerpoles themselves, cables terminated with them, and crimp tools.

APPs are pretty much the standard among ham radio operators, especially those who participate in EMCOMM. That said, I’m not a fan of them. For one, they are a bit of a PITA to assemble. Two, they are not secure when you connect one cable to another or to a plug, i.e., they don’t click into place, or even have much friction keeping them together when plugged in.  PowerWerx sells retention clips to keep two cables together, but IMHO this is a workaround for poor design.

I’ve only adopted APPs because they are the de facto standard for ham radio power connections.

Saturday, August 23, 2014

The Baofeng UV5R 2M/70cm Ham Radio

The Baofeng UV5R and variants like the UV5RA have become popular with preppers because they are a very low cost way to get into ham radio. Back in June a friend who is a new ham and I both picked up UV5RAs, and for the money, we’re both impressed with them.

As handy talkies (HTs), the Baofengs allow you to have a small, light, and inexpensive two-way radio for communication on the 2 meter (144 MHz) and 70 centimeter (440 MHz) ham bands. They can be used in simplex mode or with repeaters, allowing you to communicate over longer distances.

The Baofengs will also receive FM broadcast band stations, NOAA Weather broadcasts, and can be programmed to operate on FRS, GMRS, and MURS frequencies.

Note that the Baofengs are not FCC type-accepted for FRS, GMRS, or MURS, so it is illegal to transmit on these freqs with them unless it’s an emergency.

There are a few accessories you should get with one of these little HTs in order to maximize their usefulness:

  • The stock antenna sucks. The Nagoya NA-701 offers improved reception and transmission without being too long.
  • For use in a vehicle you want an external antenna. The Tram 1185 is an inexpensive mag mount antenna that works well. You’ll also need this jumper to go between the HT’s antenna connection and the Tram’s SO-239 plug.
  • This Baofeng speaker-mic will improve audio for both transmission and reception. (I originally got a Pofung speaker-mic but it was DOA. I returned it to Amazon on their dime and got the Baofeng branded speaker-mic in its place.)
  • When I’m using the UV5RA in my truck I use this battery eliminator to power the radio. Note that this is not a charger, despite the Amazon product description. Rather, it replaces the battery with a regulator that powers the radio from your vehicle’s 12V outlet.
  • Finally, programming the Baofeng by hand is a tedious, frustrating job. Save yourself a lot of aggravation and use your computer and this USB cable. If you already have a programming cable for Icom radios it will be compatible. Check out for troubleshooting any issues related to driver installation. Don’t use Baofeng’s software, which sucks. Rather, use the open source, free software CHIRP, which supports both the UV5R and many other radios. CHIRP is available for Windows, Mac OS X, Linux, and FreeBSD.

Everything linked above, including a radio, can be bought from Amazon for under $100.

Although my friend and I both got the UV5RA, were I purchasing again I’d probably go with the plain UV5R. The insides of the two radios are the same but there are extra capacity batteries that fit the UV5R that don’t fit the UV5RA.

This thread on Arfcom is a gold mine of information on how to get up and running with a Baofeng UV5R radio:

Despite their popularity, the Baofeng’s are low end radios. HTs from any of the Big Three – Icom, Kenwood, or Yaesu – will be sturdier and have better performance. But, they are a lot more expensive. E.g., even the relatively simple Yaesu FT-60R will run you more than three times the cost of a Baofeng UV5R. The Chinese radio is good if you’re on a tight budget or if you need to use a radio in an environment where it’s susceptible to loss or damage, and it’s cheap enough to keep extras on hand. If you have at least your Technician license or are looking to get it, the Baofeng UV5R is not a bad choice for an entry level radio.

Wednesday, August 13, 2014

How to Make "Mountain Man MREs"

Over on Survival Sherpa, Todd Walker has a nice article on how to make jerky, pemmican, and parched corn. These were traditional foods used on the trail up through the 19th Century.

Check it out here.

Sunday, August 03, 2014

Inexpensive Travel Case for Icom 7200

Many ham radio operators like to build "go boxes" which allows them to transport their rig(s) and operate right from the box. Some of these are very elaborate, incorporating power supplies, batteries, various meters, and antenna tuners. For example, the Arfcom Ham Radio forum has a long thread with links to many of these builds

I didn't want to create such an elaborate or heavy setup for my own portable ops, but I did need something better than the old Yuengling beer case that I've been using.

On the IC7200 Yahoo group someone mentioned that the radio will fit into a Harbor Freight #69318 18" x 6" x 13" aluminum toolbox. Today I took a ride to the nearest HF store to look at them in person and bought one. Note that HF sells two very similar toolboxes. The #69318 is the one that comes with pluck-to-fit open cell foam and dividers. The #69315 appears to be identical but does not come with the foam.

Here is the one I bought:

As shown in the sticker on the box, it also comes with an insert for holding tools. I removed this because I needed the interior height.

It took only a few minutes to pluck out the foam pieces so that my radio is nicely cradled in the box:

An oblique view shows the depth relative to the radio and LDG IT100 tuner:

(The tuner is secured to the radio with Gorilla tape.)

The box closes with a bit of pressure on the lid and keeps the rig from moving around. I have copies of my ham and GMRS licenses tucked behind the egg crate foam in the lid, along with a print out of the ARRL band plan.

Many go boxes are watertight. This one is not, but my use for it is transport to and from a campsite in my truck. Likewise, it's only one part of my portable setup: I still need to bring a separate power source, netbook, and of course, the antenna and mast. But, this will be easier to transport in my truck, easier to carry, and it was cheap. With a 20% off coupon the toolbox was about $25 out the door. I might pick up another one for the laptop and assorted other gear.

Friday, August 01, 2014

Going Mobile

Last weekend I was back up in Tioga County and managed to get some ham radio in.

That's my Icom 7200 radio, LDG IT100 tuner, Hawaii EARC end fed antenna attached to a 31' Jackite kite pole, which is slipped over a 4' piece of rebar pounded into the ground, and a Harbor Freight Cen-Tech 12V portable power source. The Icom's power cord is terminated with Anderson Power Poles, so I got a Powerwerx Cigbuddy adapter so that it can connect to the 12VDC outlet on the Cen-Tech battery.

The laptop is my old MSI Wind U100 netbook running 32-bit Windows 7 Ultimate. At some point I want to replace the hard disk with an SSD for a slight performance boost, but mainly for improved battery life.

I'm running FLDGI on the laptop for digital modes (PSK31, Olivia). After I replace the HDD I'll probably set it up as a dual boot system with Windows 7 and openSUSE 13.1 using the LXDE desktop environment.

Before the trip I'd received a KF5INZ Easy Digi interface to let me use my iPad 2 or iPhone 5 and PSKER instead of the laptop for PSK31. (Reviews on eHam here.) The interface itself is a nice little unit but I've been having trouble getting VOX setup correctly on the IC7200, so I wound up using the netbook this trip.

Aside from playing on HF I also got to try my new Baofeng UV5RA HT. One of my friends who just got his ham ticket (0 to General in one setting) got one for his first radio and I found it too cheap to pass up, as a backup to my Yaesu VX5RS. A follow up post on the Baofeng is planned.