Category: Communications & Receivers

Letter Re: Wifi At a Discrete Distance

It’s better to find an adapter with antenna port. This is a high-powered single-band adapter or a dual band (I’d recommend the 5Ghz band if possible, but it is still a bit rare) with RP-SMA connection. Then add a good antenna; the omni is probably equal to the Yagi. If there isn’t interference and is dual band but this Yagi will pull in from a longer distance. If you can get two and get a connector, you can put it “in the middle” like in a tree and point one at the source and one where you are using it, …


Mesh Networks, Digital Radio, EMP, and Metal Buildings, Oh My!, by R.V.

We are working on a grass roots Internet style network at my radio club. As I am a very curious fellow, I am currently reading Wireless Networking in the Developing World, which is a free ebook. This book, of which I am 1/3 of the way through reading, seems to exercise every possibility in connecting these wireless routers. The pros and cons of various management strategies and switching tactics are exhaustively discussed. Sources and software are named, making it a great reference. What got me started is the Ham Radio version of this, which is described online, which is a …


Letter Re: Heathkit Radios

Editor: I disagree with the letter regarding the unsuitability of Heathkit (vacuum) tube radios for EMP protection. Let me elaborate: Lethal voltages: While you really don’t want to tangle with +700 VDC, the most lethal voltage in any radio is that which comes from the wall outlet: 120 VAC. AC fibrillates hearts (we use it for that purpose in cardiac surgery); DC defibrillates hearts (done that many times). Requires 120 Volts AC: Unless you get the 12 volt power supply (I have two). Or solar power / inverters.…right? No cooling fan: Well, they rarely need it! My primary rig is …


Letter Re: Using EMP-Hardened HF Ham Radio

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Hugh, I strongly recommend against using any Heathkit rig for an emergency radio. There was one solid state Heathkit but it was a rebadged, factory assembled Yaesu. All others were built by an individual, whose attention to detail you most likely have no idea about. They are known in the hobby as “GRIEF kits” for a GOOD reason. They fail – early, and often. They have too many disadvantages for the emergency backup purpose. Besides all the ones mentioned by the original author: They have high (LETHAL) voltages inside. They require 120V AC power. They have no cooling fan on …


Letter Re: Comms Using Photos – Would This Work?

Hi Hugh and James, I just finished reading The Religion War by Scott Adams. It’s a short, very good book about Christianity vs. Islam in the future as both sides prepare for war. In it, he wrote something that made me curious if it would work. In order to defeat the use of computers scanning emails to find key words or phrases, his characters do something I’ve never thought of. “Cruz’s intelligence forces electronically searched every message that crossed the Internet, but their sniffing programs were looking for text, keywords, key phrases, and encrypted files. (His people) thwarted the filters …


Using EMP-Hardened HF Ham Radio to Send/Receive E-Mail During Nationwide Outage- Part 2, by PrepperDoc

Transmit-Receive Frequency Offset This should be zero. Synthesized digital radios have no problem accomplishing this; however, vacuum tube rigs may struggle. Surprisingly, the less expensive HW-series transceivers and the SB’s with the vacuum tube based LMO (VFO), in my experience, have little shift between transmit and receive. Later SB-series transceivers with the solid-state VFO may have an offset. If this offset is > 100 Hz, you’ll notice it during SSB conversations (“leapfrogging” as you chase the fellow you’re talking to), and you’ll want to fix that for digital communications. Happily, the solid state LMO includes a FSK (frequency shift keying) …


Using EMP-Hardened HF Ham Radio to Send/Receive E-Mail During Nationwide Outage- Part 1, by PrepperDoc

There are multiple possible scenarios that may result in a regional an/or national combined loss of Internet connectivity and cell/telephone service, during which you would probably wish to maintain communications to loved ones and others. EMP may destroy routers, cell towers, and power sources; solar coronal mass ejection (CME) may remove power from all communications systems; cyber warfare may have similar outcomes. Travel in some of these circumstances will be difficult, or dangerous to impossible. Ham radio VHF/UHF repeaters may go down, due to power outages or EMP. Direct, point to point simplex VHF Ham radio will still work (even …


Letter Re: Grid Down Digital Library

HJL, Downloading YouTube on Android. Remember micro-SD cards are interchangeable and inexpensive, so get a phone with a slot and make backups (and put them around various places). Often large (128Gb+, often U3 for GoPro) capacity cards will go on sale at least once a month, so I look for them and stock up. I’ve seen these as low as $15, limit 2. Sometimes there are excess stock or closeouts on prepaid, and I didn’t have to activate them though there was a trick to bypassing that screen. Most can be rooted. I have several, so it pays to look …


Letter Re: Learning Morse Code

Hugh, You may find a quick blurb about the following site gets quite a good reader reaction. As a Ham of just under five years, the best site and aid I’ve found to learn Morse code is at lcwo.net. They focus on the Koch method and have several types of training courses. In just a few weeks of daily training, you’ll find that your comprehension will pick up quickly enough to start picking up operators on the air. – A Ham in Colorado


Letter Re: Prepaid Phones

HJL, Yes, criminals use prepaid phones, but patriots do too. I have been using a monthly, no contract, prepaid phone for over 15 years. Why? Because I do not like contracts, hidden fees, data charges, et cetera. I use Virgin Mobile. For $35 a month, I get unlimited calls, messaging, and Internet. There are no hidden fees or surprise charges, and I do not have to surrender my personal information or SSN. I like having to NOT give up my personal information every chance I get. So, understand, it’s not just criminals who use these phones; it’s also the poor …


Letter Re: Advice on Learning Morse Code

Hugh, Learning the Morse code is not particularly difficult, but there are several common pitfalls that typically interfere with the learning process. The best advice I have for learning the Morse code is to get together with someone who is proficient with the code and work one on one with that person. This way, you can avoid developing bad habits that you will have to unlearn later. If such a person is not available, then learning the code becomes a bit more difficult. The most important thing to keep in mind is that the Morse code is an aural language. …


A Random Walk Through The Risks of Silicon Valley, by Epaminondas

As a technology executive who has worked extensively with most of the big, high-tech firms (Microsoft, Google, Verizon, Dell, Qualcomm, and more), I thought that it could be helpful to share a perspective on the general role of technology on prepper thinking and planning. This readership is much more sophisticated than most, but the hard fact is that most of us cannot live an independent, off-grid lifestyle for a variety of reasons. Technology is the great enabler and force multiplier that can make it much easier to work remotely, maintain close contact with family and friends while benefiting from the …


Letter: Advice on Learning Morse Code

Dear Editor, I have noted that the main characters in your novel Survivors use continuous wave (CW) Morse Code on occasion to stay in contact, around the globe. As a relatively new ham radio operator I am fascinated by CW Morse and have been trying to learn it for a couple years without a lot of success. Any words of wisdom or proven “best method” to learn CW especially for the over-50 age group? – J.S. HJL Replies: There are a variety of inexpensive Morse code instruction tutor apps that will run on your smartphone or personal computer. While there …


Letter Re: The Vulnerability of Many Commonplace RF Electronics

Dear JWR, Regarding the recently linked article on the hack of the Simplisafe alarm system, I’d like to alert readers to the fact that many, many radio frequency (RF) devices available on the US market have similar vulnerabilities. But it’s worse than that. These devices operate on one of several unlicensed radio frequency bands authorized under Title 47, part 15 of the FCC rules, most specifically Section 15.231. There are transmitters available for purchase on 433MHz, as used by Simplisafe, and they are quite inexpensive. Many of these evaluation kits only require attachment of a battery and you are ready …


Letter Re: Shielding Electronics From EMP

HJL, Another point on electromagnetic pulse (EMP) and Faraday cages is even something simple can be protective. There are 30 Gallon galvanized steel trash cans with lids (made in the USA!) available at my local farm and ranch store for $22. This makes for affordable and easy storage, and you can wrap things in common aluminum foil. Or even something like a steel cabinet or vault, but generally try to avoid gaps or spaces. It doesn’t have to be zero signal, but reduce the field strength enough to prevent damage. Vehicles have some protection for many years. In the early …