Covered Topics

Please see the list of the topics I've covered. It's located near the bottom of the page. Thanks for stopping in!!

Saturday, May 24, 2014

Amateur "Ham" Radio, Shortwave Radios, and Preparedness

On this blog, I have written about the need for having a shortwave radio for monitoring breaking news events. Good shortwave radios are expensive and hard to come by - hence my building the TenTec radio I mentioned in my last post. Hopefully with the Spring semester over I can catch up on supplying content to this blog and my video channel on YouTube. http://www.youtube.com/user/KarlsLabReport

One of the things I have wanted to do is a post on what to look for in a shortwave radio.

During civil emergencies, communications such as landline phones, Internet, and even cell phones often fail. While a cell tower may continue to operate on emergency backup batteries or fuel cells for some time after a crisis, that tower can be taken out by a tornado just as surely as phone and electric wires can be. Service may be deliberately cut off by terrorist acts or by government edict as well. Both in Egypt during the unrest in 2012-2013, as well as the incident at the Bundy Ranch in Nevada this past April (2014), government officials cut off most telephone and Internet access to the area. None of our media outlets covered the Bundy Ranch incident until Alex Jones exposed on his website the connection between a certain politician and a Chinese corporation as the main driver behind the whole fiasco. Then there was the near-mishap in 2011 at the Fort Calhoun plant in Nebraska, caused when the Missouri River flooded, which was NEVER to my knowledge covered in the American media. I think it is safe to say that this type of information blackout will be Standard Operating Procedure from here on out whenever anything controvercial happens.

In the case of the bundy Ranch episode, amateur radio (ham) operators were helpful in getting news in and out of the area and even transmitting pictures via some of the digital operating modes available nowadays.

I have several ham radios - a VHF handheld for the 2-meter band, a ham radio I inherited from my dad that will cover all the "HF" bands below 30 MHz, and some homebuilt equipment for the 7 Mhz (40 meter) band. Recently, I got the handheld out, dusted it off, and discovered it still works after 15 years of non-use. This past week, I took the HF rig of my dad's to a buddy's house and we almost immediately were able to talk to someone several hundred miles away. Imagine for a minute if your local landline and cellular communications stopped working - how valuable would it be to you to be able to flip on the ham radio and hear what is happening in the world outside, or even talk to someone who has information? One afternoon a week ago, my buddy and I talked to a guy in Slovenia on the 17 meter band (18.068-18.168 MHz) using 40 watts of transmitter power into a random-length wire antenna. The propagation conditions were favorable and his signal came in so clear he literally sounded like he was across town. Now, I'm NOT saying one would radio Slovenia to find out about a situation a few states away in the USA, but the point is amateur radio potentially gives you tremendous communications reach. The following link gives you an idea of what you can hear and, given the appropriate license, can transmit on which frequencies:

http://www.arrl.org/band-plan

Licensing: NO license is required to LISTEN to amateur radio transmissions. In order to TRANSMIT, you MUST have a license or have a licensed amateur radio operator present when you are doing so. In recent years, the FCC has eliminated the Morse code requirement from any of the 3 license levels. For decades this was a stumbling block for many folks and while many amateurs STILL use Morse code, and thus is is a good idea to learn it, you DON'T need it to get a license anymore. The three license levels are Technician, General, and Extra class. The main difference between the levels is the amount of frequencies and operating modes you can use; also as you go higher in license level the amount of electronics and radio knowledge required goes up. Testing, which is required to get your license, is conducted by a network of "volunteer examiners", or "V.E.s". VEs are radio amateurs who volunteer their time to give the required FCC exams to new folks wanting amateur licenses. VEs can be found through local amateur radio clubs and by going online to the ARRL's (Amateur Radio Relay League) website at www.arrl.org.

The written tests for Technician and General consist of 35 multiple choice questions taken at random from a standardized FCC question pool; the Extra exam consists of 50 multiple choice questions. On the Technician and General, you are required to get at least 26 of the 35 questions right (75%) to receive a passing grade. For the Extra, you must get 37 out of the 50 (again, 75%) correct.

How to get started and Where to go for help:

Here are a couple very helpful sites for practice quizzes and more information:

http://aa9pw.com/radio/

This site has more practice exams and reviews of radios and equipment:

http://www.eham.net

TenTec Radio Kit - Model 1054 Update #3

My longtime readers will remember I built a TenTec Model 1054 regenerative shortwave receiver kit a while back. At the time I posted to this blog about the apparent bad customer service I received from TenTec when complaining about the erratic regeneration control. Just week, there has been another development.

This past week I have been working feverishly to get all my ham and shortwave equipment up and running. After an exhaustive and *fruitless* search online, trying to find any information I could on the TenTec 1054's regeneration control issue, I decided to try once more to contact TenTec's customer service people. TenTec apparently has NO PHONE number to reach them at; apparetly one must email them as I had before. And so I did.

The following day I got an email back from one of their service technicians stating that my original email had gone into his email "spam folder". He also stated, contrary to the instruction manual, that the regeneration will start 1/4 of the way from one end of the potentiometer's travel, that regeneration will start rather suddenly, and that from my description the radio seemed to be working correctly. ANOTHER tech later wrote me and said that he thought there was a defect in either one of the two FET transistors in the regeneration circuit or that the regeneration threshold adjustment trim potentiometer was bad. He offered to send me new parts free of charge if I sent him my address. I did just so; I'll see what happens.

If they do not end up sending me the parts (I'm NOT holding my breath, under the circumstances), after studying the schematic at some length I have some ideas as to how I can modify the circuit to work better.

All this said, I still have the issue of what to do about the housing, since the box TenTec sent me is basically unusable. As mentioned in my original post I intend to do some circuit modifications such as adding a dual 9-volt regulator circuit that can be fed from an external 12 volt battery, and possibly adding a band spread control for better selectivity in crowded bands. I want to build my own improved audio section based on a decent audio chip. I would also include an active filter for CW reception and a limiter to prevent hearing damage from loud noises. Regarding the dual 9-volt regulator, the circuit currently uses separate batteries for the regenerative receiver itself and the audio section. This is no doubt to eliminate any issues from feedback and oscillation between the radio part and the audio section. But for my purposes I need the whole thing run from one 12 volt battery.

Here are the links to my prior posts regarding the TenTec Moel 1054 radio:

http://inkarlslab.blogspot.com/2011/04/ten-tec-short-wave-receiver.html

http://inkarlslab.blogspot.com/2011/05/ten-tec-model-1054-shortwave-radio.html