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Topics - gil

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316
Technical Corner / The Retro-75 AM 75m Transceiver Kit.
« on: July 24, 2012, 09:17:55 PM »
Hello,

Another success! I got a Retro-75 from Small Wonder Labs and a nice blue case from TenTec, put the whole thing together in a couple days. It works. 75m AM is good for regional communications, but requires a very long antenna... I haven't built one yet. That's around 120ft of wire, if I am not mistaking. The quality of AM voice is great.



The Retro-75 is crystal controlled, with two crystals of your choice on the board. That's what the A/B switch is. Transmit is keyed by switch or press-button. It is extremely simple to operate. Output power is 3W.

That's what I love about kits, they will give you a working transceiver for often less than $100, capable of long distance contacts. That way you're not eating into your other prepping supplies budget.

Gil.

317

The one question that comes to my mind regularly is: What bands and radios should I have to cover all possible emergency situations? The answer would be easy assuming a ?bug-in? situation. Taking mobility into consideration turns it into a whole new ball game. Not to mention cost. So, let's see what needs to be covered in terms of range and how it affects transceiver and antenna choices. I divide communication needs in three ranges:

  • Local: Within the family, group, or neighborhood.
  • Regional: Within a 250 mile radius.
  • Long distance: State, country and worldwide.

Local and regional ranges need to be absolutely reliable. Long distance, well, that's another story..

Local: A couple pairs of FRS radios will do fine. Your neighbors might have some too. Reliable range is limited to a couple miles (don't believe the ads), but they are light and small. It is more likely that someone could be listening in on your conversations, so you would have to keep that in mind. When splitting a group, even for short times and distances, you need to remain in contact. Anything can happen, and you do not want to lose anyone, especially family members!
A couple 2m handhelds could be very useful as well, to extend your range. Look at the Slim Jim antenna article I wrote in the antenna forum. You can hoist it up a tree, and it is portable.. You could count on a reliable 30 mile range. This would allow you to pick-up chatter from other groups, and learn about the situation around your position. Emergency Ham organizations would be using that band. Valuable information could be gained by scanning those frequencies.

You might also consider marine and aviation band handhelds. They cost about $200, and are pretty small. This adds gear to carry however, so plan wisely. You don't need a marine radio in Kansas..

We are up to already two or three handhelds, and we need to keep things light and small..

Regional: Two possibilities here, HF using NVIS (Near Vertical Incidence Skywave), or VHF using troposcatter propagation. For HF, you would need an 80m or 40m radio, with a pretty long dipole close to the ground. While a wire antenna packs easily, it takes a lot of space to install, and requires some kind of support, trees or poles. In a vehicle, you can have a base-loaded antenna up front, bent backwards and attached with a string to the rear bumper. The short antenna requires more power to get out, but you have a car battery for that. On foot, the antenna issue is more of a problem, especially on the move. See hfpack.com for information on portable HF.
One band that is probably under-appreciated is 2m SSB. Ranges of up to 250 miles can be obtained using beam antennas such as the Yagi-Uda type, which remain small and portable. I bought myself the MFJ-9406 6m SSB transceiver, but I might trade it for a 9402 model on 2m. That way, I can use the same antenna (assuming a wide enough tuning range) as my 2m FM one. Arrow Antennas (http://www.arrowantennas.com) has foldable Yagis at good prices..

Some thoughts about 6m... It is a great band that can use almost all modes of propagation, sometimes behaving like HF or VHF. If I could have only one radio for everything, that would be it. Like a seaplane is a bad boat and a bad plane, 6m has it's quirks, especially for long distances. Without solar activity, it is a local/regional band only. A 6m beam antenna is much bigger than a 2m one.. If everyone used it, it would be great, but it isn't the most popular band. 20m and 2m SSB radios will do everything 6m does, only better. Sure, that's two instead of one, but reliability is increased a great deal, especially on 20m.

Finding someone to talk to on HF is easy. On 2m SSB, it is another story. If you have relatives or friends within 250 miles, I would suggest setting them up with 2m SSB. That band only requires a simple Technician license, which anyone can easily get.

Long Distance: This means HF, and bouncing signals off the ionosphere. A CB radio can do that, using SSB, but only during the high part of the sun cycle (we are in it right now). If that's all you have, great. For more reliability, I am thinking of 20 and 40m. HF radios, but for a few exceptions, tend to get heavier and bulkier. Antennas get much longer, especially under 7mHz. There is however one mode that offers very small radios, low power consumption, and the best reliability, that is CW (Morse code) transceivers. My Elecraft K1 is the perfect example, with 20 and 40m bands. It uses only 55mA of current on receive, and packs in a small box. You can go extra small with a Rock-Mite from smallwonderlabs.com. I have one in my bug-out bag, with an end-fed wire antenna. You can transmit on 40m CW with a Technician license. Though a license would mean little in a real life-threatening emergency, practice makes perfect.
A small SSB single-band transceiver would work fine, if you don't want to learn Morse code. I like the MFJ-9420 and 9440 models. Be careful with MFJ products though, some are quite junky, but their transceivers work great. The BitX20 would be great too. It comes in kit form. See qrpkits.com.

There are radios that cover all the bands I mentioned. The best example would be the Yaesu FT-817ND, which amazingly covers from 160 to 2m I believe. It is very small for what it does. I am sure I will eventually get one. One reserve however: If your radio goes dead, you lose all means of communication. Buy two or have other radios as backups.

Short Wave reception: You might want to have a good Short Wave receiver for information gathering purposes. With the capability to receive both amateur lower bands and commercial broadcasts, you can be sure to know what is going on. I have my eyes on the MFJ-8100K, which seems like an affordable nice week-end kit project.

We now have two or three handhelds, two small transceivers, a Yagi-Uda or Slim Jim antenna, and an end-fed 20/40m (I have a PAR end-fed) wire antenna. Not bad, and not too heavy.. What else do we need?

Power of course. All these radios run on 12vdc. I use a 2.9Ah gel-cell battery to power everything (not at the same time). My next purchase is a flexible 10W solar panel (http://www.powerfilmsolar.com) and small charge controller (http://www.buddipole.com/sobaco.html). Don't forget EMP protection, get Faraday bags for each of your radios. I am also planning on getting a Pelican 1400 case for my K1.

Thanks to the recent trend of ?QRP? Ham Radio, it is now possible to cover most useful bands with small and light radios. My Rock-Mite, one FRS and a 2m handheld live in my bug-out bag, along with an end-fed wire antenna for 20/40m and a power cable with alligator clips. The rest of my radio equipment goes into another bag, meant to be carried in a vehicle or on a cart. Right now, my HF radio is the Elecraft K1. My 2m is a Yaesu FT-270R. I have a pair of FRS radios. My SSB CB radio would go in my vehicle bag as well, with another wire antenna. This makes for a heavy bag, with the other stuff I plan on putting in it, camping gear, some clothes, and other useful items. This second bag should be light enough to be carried on foot for short distances. The bug-out bag would never leave my back, wherever I go..

Your thoughts and comments would be appreciated... Thank you.

Gil.


318
Tactical Corner / The Ever Useful Good Old Morse Code.
« on: July 05, 2012, 09:58:12 PM »
I never thought of learning Morse code for emergency preparedness. Spending untold hours learning an archaic mode of communication wasn't on my list. I started looking for a small, portable SSB (voice) radio that would fit in my bug-out bag. The FT-817ND and MFJ-9420 caught my attention. The price of the Yaesu put it temporarily out of reach, and the MFJ was still around $300 shipped. Both radios are small, but not quite small enough for my bag. Maybe I would use one of them as my main radio, but I still needed a BOR (Bug-Out-Radio. I coined that one.. ;-)

After a few hours of web browsing, I somehow stumbled on the Rock-Mite kit, a CW ('Continuous Wave,' i.e. Morse code only) tiny transceiver from Dave Benson at Small Wonder Labs. Here was a very small radio with a 'sporadic range' of thousands of miles, for a mere $29! ($70 with MityBox and connectors). Many people mount them in a mint tin can. It took me a few hours to build the kit, which worked the first time, with no tuning required. My 20m version transmits on 14,059kHz. I just finished a 40m model as well. By the way, if you visit http://smallwonderlabs.com, see how Dave Benson built his own house in the woods! Pretty inspiring.

As I was pondering about learning Morse code, which I mistakenly considered a small detail, it hit me..  Morse archaic, when? Aren't many of the skills we like to learn archaic? Trapping, hunting, food preservation, living off the land, field medical procedures, camping, building shelters, etc. The kind of skills that can save your bacon when everything else fails. Morse is one of them! It can be used without a radio. You can tap your fingers, blink your eyes in Morse, and nobody but the intended recipient across the room would know.. You can bang on a pipe with a wrench, hit a drum, squeeze someone's hand, use a flashlight or a laser pointer to send a message in Morse. If regular means of communications were down, because of an electromagnetic pulse for instance, a simple telegraph could easily be built without using semi-conductors. The wires are already all around us.

With that epiphany in mind, I bought an Elecraft K1 kit. It is a 2-band version, 20 and 40m, covering 175kHz at the bottom of each band. I added the internal automatic tuner to be able to use random long wires as an antenna if needed.

Now I really have to finish learning Morse code!

Communications within your group would be via VHF or UHF, maybe 2m or FRS, even CB. For HF long distance, CW simply gets you more bang for your buck, especially in very small packages. It will punch through the ether with less power and more reliability than voice. My K1 uses very little current on receive (60mA), and runs for many hours on a small 2.9Ah battery. I will be getting a 10W solar panel soon to complete my kit. The Rock-Mite lives in my bag. The K1 will get a waterproof Pelican case (1200 model). Both will get Faraday bags for EMP protection. My antenna is a PAR 40/20/10 end-fed dipole. It packs into a small pouch. I also have a SOTA tuner from http://qrpkits.com, and wire for a 20m antenna. I really like the tuning bridge and SWR LED on the tuner. Perfect for the Rock-Mite 20.

Morse code is not archaic, far from it. It is an excellent mode of communication usable in many different ways, not just radio. The more I think about it, the more I find possible uses for it. Prepper families and groups should learn it. You never know when the need may arise.

Gil.

319
Antennas / The Solarcon I-Max2000 CB Antenna.
« on: June 26, 2012, 09:02:29 PM »
Hello,

I thought I'd drop a note here about my Solarcon I-Max2000 CB antenna.. I was initially going to buy the A-99, but some bad reviews made me choose the longer (24'), better built model. The I-Max2000 mind you is not much more than a wire in a fiberglass pole. You can actually hear the wire rattle inside the tube. The magic is in the matching unit at the base. Although it can be used without a counterpoise, it does work better with one. I suspect the antenna to be sort of an end-fed dipole, though it is a 0.64 wavelength.. I am no expert.. I also suspect that the coax shield works as a counterpoise when a suitable one isn't present. That is why I use it with ferrite chokes on the coax at the antenna.. But enough techno-babble..

I've had very good results with this antenna. "NVIS." NVIS is when a signal is directed straight up and bounces on the ionosphere back down, covering a few hundred-mile radius. This is different from the usual low angle, long-skip pattern desired in multi-thousand-mile contacts. The radiation pattern of the I-Max is pretty vertical.. However, I do not think NVIS is possible on the 11m CB band.

My first two contacts were, unbeknownst to me, Jamaica and Western Utah. I thought these guys were local until they told me their location! They sounded that good, and they heard me just fine. I was using legal power on LSB. Even with the high angle of radiation of the I-Max, the signal was skipping off the ionosphere.

I like the light weight of the antenna and it's fiberglass construction. It is made of three 8ft. sections bolted together. It is very flexible and holds up fine in windy conditions. I did paint it dark green, and with the trees around the house, it is nearly invisible. It is also pretty cheap, which is the cherry on top of the cake.

I do highly recommend it. I have heard it can also be used on 10 to 17m with a tuner.. See the Eham reviews. Users rate it 4.5/5.


320
Technical Corner / I Built an Elecraft K1!
« on: June 12, 2012, 07:08:03 PM »
It's alive! After three hair-pulling days, the radio finally works. I received the box on Thursday night; no time then to start, but I got to it after my daily work session on Friday. Late that night, I had completed the filter board, one of the three circuit boards.

I must here explain what an Elecraft K1 is.. Though it sounds like some fighter plane name, it is a receiver/transmitter (a "transceiver") which transmits, and receives CW (Continuous Wave) Aka "Morse Code." It is very small, and covers up to four Ham radio bands. Mine has two, 40 (7Mhz) and 20 meter (14Mhz). The power output is fairly low (7 Watts), but that is sufficient to bounce your signal around the earth.. Imagine seeing a 7 Watts light bulb thousands of miles away! Somehow, it works. CW punches through further than "phone" (voice). The K1 is in a class of radios called "QRP," meaning low power, usually 5 to 10 Watts. It is only sold as a kit, so if you want one, you must build it, or find a used one.. I chose to build it..

I don't understand the fear about winding toroids. I find it very easy and relaxing; it hurts much less than it sounds. All you have to do is count how many times you thread a wire through a ferrite core. How easier can it be? Then, you burn the enamel off the leads with a lighter, clean them up with your snipping tool, and solder.. I was very exited that night about the project. I thought it would be a walk in the park.. Not quite..

The front panel was next. The only difficulty there was soldering the LCD display. Attaching the wires to the ten-turn potentiometer also required some dexterity. About wires.. There are very few in the K1 kit: The potentiometer lead wires, speaker wire, and one coax jumper on the back of the board, that's it. Everything else is connectors. I like that. Soldering wires is always a pain in the butt.

The RF board was the biggest and longest one to build. It took me from around 10-am on Saturday to about 2:30-am on Sunday to complete it! And it didn't work! In retrospect, I should have only completed the receiver part that day, leaving the transmitter for Sunday. When tired, your brain plays tricks on you, and you make mistakes. Everything went fine with the receiver. I heard static when I turned the K1 on, no smoke. After tuning the receiver and plugging-in a long wire, I was listening to CW on both bands. I was exhausted, but proceeded with the transmitter side. It was 9-pm already, eleven hours of looking at tiny components, placing and soldering them.. Then came the time to test voltages on the RF board. Nothing on U8! Shit! Excuse my French.. That wasn't good. I nevertheless plugged-in the filter board to test power output. Nothing.. Followed about an hour of tinkering, swearing, manual-reading, head scratching shenanigans, of which I remember almost nothing (I had been working on it for 15 hours straight). I rewound the bi-filar transformer, reheated solder pads both on the filter and RF boards, zilch! Then I gave up, and decided to complete the build for the heck of it, and call Elecraft in the morning. Yet, after putting the speaker in and closing the box, I tried again. Power on 40m! Not on 20.. Ah.. Back to it (2-am).. I think I transmitted without a dummy load and no antenna a couple times by the way, I was so tired. Anyway, I have no idea what did it, but after countless little troubleshooting steps, and more tuning of the filter board, I finally got output power on both bands. I packed it up and went to bed with a headache and slight twitching..

Comes Sunday morning, I had a working K1! The only peculiar thing left to investigate is some power fluctuation.. If I set the maximum output to 2 Watts, the watt meter shows 2W at first, but then slowly climbs to 2.8. I am guessing that the final transistor produces more gain as it warms up.. I even produced about 10W tuning the filter board before the output suddenly dropped! Weird.. After tuning the filter board on receive, things are a bit more stable, still with quite a power increase as transmit time increases.. It shouldn't occur producing CW though, as this was transmitting a continuous tone in tuning mode. We'll see..

I spent Sunday evening listening to CW outside, with a wire strung horizontally (20ft maybe) about five feet from the ground; the worst possible antenna. Still, it was easy to pick-up signals. I even heard a guy saying he was on a sailboat, and retired three years ago (I have a Morse decoder app on my iPod!).

The Elecraft K1 kit is of very high quality; much better than any other kit I have seen so far (five). Everything fits perfectly, nothing was missing. I even had much needed left-over screws (I spilled them all on the garage floor).. The box looks great, and the way the circuit boards are positioned and fastened is brilliant. I will order the automatic antenna tuner and add it in soon. For now though, I need to finish learning code, then I'll go for the General Ham license (CW is no longer required). The K1 was the right choice, at the right price. You get a lot for your money. It might not seem so when you buy the kit, but after building it, I find it very affordable.

To anyone contemplating building one, go for it! Build a couple kits first, like a Small-Wonder-Labs Rock-Mite, and a SOTA tuner from qrpkits.com, and you'll be well on your way. Moreover, you can test the Elecraft receiver with the Rock-Mite! Get 50ft. of wire from Home Depot for the SOTA tuner, and you'll be all set. Follow the manual EXACTLY. Don't skip ahead, read every line! Double-check everything. Most importantly, don't do what I did. That was stupid. Take your time. If you feel tired or stressed, stop, rest, and don't get back to it until much later. I was very lucky that I didn't fry anything. Not to mention the stress and lack of sleep.. Not a healthy way to spend a week-end..

In the mean time, like they say over there, "Everything is fine in the best of worlds." I am a happy, proud builder and owner of an Elecraft K1. The satisfaction of building something that complex with your own hands is priceless..


321
Technical Corner / Building a Rock-Mite 20m CW Transceiver kit.
« on: June 08, 2012, 04:05:51 PM »
After my semi-success with the DC20B, I decided to tackle the Rock-Mite from Small Wonder Labs. I also got the Mighty Box. The kit is very small and has no toroids to wind. It does however have a surface-mounted integrated circuit. Winding toroids is actually very easy. I don't know why people make such a big deal of it. Maybe they just haven't tried. Soldering the SMT circuit, while not that hard, was stressful. That being out of the way, the rest of the kit was a breeze. Being fairly confident of my abilities, I installed the circuit board in the box without trying it first. This way, I could use all the connectors for testing. To my satisfaction, it worked the first time!

My goal with this Rock-Mite is two folds. First, it is a stepping stone to building an Elecraft K1, which I have just started, and second, it provides me with a small emergency radio for my bug-out bag.

I can't really compare the DC20B to the RockMite as far as performance is concerned, but building the Rock-Mite is easier, and there is no tuning required. The circuit board is slightly smaller. I replaced q6 with a 2sc799. R18=2.2 ohms for a little more power. The keyer is the Pico Keyer from http://www.hamgadgets.com.

I am very exited about building the K1. More on that later...


322
Technical Corner / Elecraft K1 Decision.
« on: June 03, 2012, 02:30:16 PM »
I decided to build an Elecraft K1. What the hell is that You might ask.. Though you probably guessed it is a radio. I'm on a roll. I know, I know, I just finished building a small one (DC20B) and am waiting for another tiny transceiver called a Rock-Mite. You need to learn to walk before you can run.. Why not buy something already made? It isn't more expensive.. Well, the Elecraft K1 has an excellent reputation, and it isn't sold assembled. If you want a new one, you must build it. I am good at that stuff, and do enjoy the process. Still, I could find a working Ham radio on Ebay for the same price; but that would be a used item. Not to mention that the K1 is the cutest little radio (did I just say that?).

There is one peculiar thing about this radio, aside from all it's qualities, that is, you can't talk in it.. Morse code only! Also known as "CW" (continuous wave). So I am learning Morse code, and it is far from easy. Why bother? First, a Morse-only transceiver is much simpler and smaller than an SSB (voice) one. It draws less current, which becomes very important when operating on batteries. The K1 will happily work for days on eight AA batteries! For example, a Yaesu FT-817ND draws 450mA on receive. The K1 draws 55mA! More importantly, when propagation conditions are bad, a CW signal will punch through the ether when another mode won't. In an emergency, being heard might be a life-or-death condition. Even with no cell phone coverage and no satellites overhead, there is a good chance the K1 will be heard somewhere, even thousands of miles away. Yes, thousands of miles directly, on eight AA batteries! What else can do that? It doesn't mean I won't take my cell phone or a Spot when hiking far from civilization. However, cell phone coverage is spotty in the North West, and with the Spot, you can't specify the type of emergency, and can only use it for dire situations. If I need anti-venom after a snake bite, it won't do me any good to get picked-up by a helicopter if they don't have the serum with them.. A radio allows you to call for a specific kind of help. Like any other gear, if it is too heavy or too big, you will most likely not take it with you. Light and small is better when you need to carry it on your back.

My plans are to first complete the 20/40m model with no add-ons. Then, I will build the built-in antenna tuner. This option allows you to use a random wire as an antenna without risking frying the transmitter. If you lost your antenna and all you can find is a length of barb wire, the tuner can save your bacon. Just hang it up a tree, press the tuner button, and seconds later, if you're lucky, you will be having a conversation. I might add a noise blanker later.. One item I decided against is the built-in battery pack. You can't charge the batteries while they are inside the case, so what's the point? I heard it is a flimsy add-on anyway. I don't think I'll need more than two bands, but time will tell. The antenna I chose is the Par EF-10/20/40 MkII end-fed dipole. Also on my wish list is a solar panel (PowerFilm AA Battery Solar Panel Charger) to charge those AA rechargeable batteries. For EMP protection, I decided to get some TechProtect Faraday bags.

I will document the build and post it. Average build time is about thirty hours, but I am pretty fast with a soldering iron. I will start next week-end (June 9th), stay tuned for the article, and maybe a video. Hopefully by then I will have learned a few more letters of Morse!


323
Net Activity / 6m AM.
« on: May 14, 2012, 04:07:58 PM »
Hello,

I really would like to organize a 6m AM Net. I have a Gonset Communicator III, and nobody to talk to once I get my license...

Gil.

324
Technical Corner / Building a DC20B 20m CW Transceiver kit.
« on: May 14, 2012, 04:05:55 PM »
The DCxxB from qrpkits.com fits in a box the size of a pack of cigarettes and allows you to make contact all around the world! For $30, how can you go wrong... I thought the best emergency radio is the one you will take with you. The DC20B (there are other bands available) certainly fits that bill. I also ordered a frequency counter kit from N3ZI to help setting it up.

The circuit board it small: 3.5"x2.5". All the components come with the kit, with the exception of plugs needed to mount the PCB in a box. Actually, the kit was missing an integrated circuit socket (I found one at Radio Shack), and had two extra transistors..

It had been a long time (27 years) since I had finished electronics school. I had never soldered on a double-sided circuit board, but it turned out to be fairly easy. I just made sure I had a nice solder joint on both sides. The resistors went in first, then diodes, and so on, mounting the shortest components first, finishing with the talents. This way, you can use a piece of foam to press the components side onto it while you solder on the other side. This keeps the components near the board. One exception is the transistors. You don't want to overheat them, so it is better to mount them a little further out. The final output transistor is not put in until the kit is finished and tuned. Transmitting without a tuned antenna could destroy that component. Winding the coils was a pain. You need to make sure you count the turns carefully. One turn is every time the wire goes through the center. The parts are so small, I needed to wear reading glasses!

When all the components were in, I cut off the plug from old headphones and soldered them in. I also soldered a long wire as an antenna to test reception. It worked! I did hear faint morse code and SSB voices when tuning. The oscillator frequency however seems to be wrong: 14,063.2 Mhz instead of 14,060. I am not sure if there is a problem with the frequency counter, or I am that far off. The morse code keyed works too, so I have a working radio, except for the output frequency. I will need to find someone with an HF ham radio to check my tuning. I am investigating a way to fix the frequency problem and measure it accurately for sure. My progress will be posted here soon, as well as the mounting of the project in a box. Now I just need to learn morse code; darn, why didn't I think of that?

Update (May 27th): I think I am going to ditch the DC20B. I have a box for it, and should complete the build, but after that, it's going away. I can't get it on frequency, and I am not the only one... The Rock-Mite kit should arrive this week. I can't wait to build it. Look for the article!

Update (May 30th): Well, I gave it one last try.. Changed C36 to a 100pF, and C29 to 47pF. It worked! Now I get 14,059.72 on transmit. Receive goes from 14,060.16 to 14,060.32, a perfect 600Hz offset. The problem is the receiver, which has no selectivity. I receive Chinese, French and Spanish commercial radio stations, but little, faint CW signals. Maybe the problem comes from the wire I use as an antenna, which isn't tuned. I will try a tuned dipole during the day and see if I can get clear CW (morse code). I boxed up the DC20B in a nice Hammond cast aluminum box. I made a hole in the cover to tune CT1 and glued a piece of coax outer insulation so that I can't touch anything with my screwdriver upon insertion.. The box is a little big, but it looks good and as though it would survive being run over by a semi-truck.. I might make another hole for access to CT2 and add an RCA plug for a frequency counter (for tuning).

Still waiting for the Rock-Mite (shipped today).
Elecraft K1 arrives tomorrow (June 7th).


325
CB / Galaxy DX 979 CB Radio Review.
« on: May 12, 2012, 11:18:32 AM »
I wanted a small CB radio with Single Side Band (SSB) that could be used for emergencies. The Galaxy DX 979 seemed to fit the bill. At a mere $140, there wasn't much of a risk. I knew I was getting a cheap radio and did not have high expectations, only a few requirements: Small size, SSB, and perfectly legal. That means forty channels, AM, USB, LSB modes, with 4W max on AM and 12W on SSB (PEP). Not much, but you would be surprised (I was tonight) at how far you can reach with just a few watts, as much power as a small bicycle light bulb!

Most people know the Citizen Band through movies like "Smokey and The Bandit," "Convoy" and others, mostly involving truckers. That is just one side of the coin. The other side are the operators trying to cover the greatest distance possible, and activity called "DX."

CB has a good thing going for itself right now, that is the peak of solar cycle 24. Propagation is going to be very good for probably another couple years. Radio waves in the 11m (27Mhz) band do bounce off the ionosphere when conditions are right. SSB being excellent at receiving weak signals, you have a very good chance to skip pretty far.

The Galaxy is cheaply made (compared to a Yaesu HAM radio of similar price). The buttons on the front panel are "chromed" plastic and look cheesy. The whole radio looks and feels cheap. I even had a very hard time putting in the mounting bracket screws. I had to tighten them with a pair of pliers and was lucky not to strip any thread. Looking inside the box gave me the same feeling. I like the big meter and the fact that you can dim the blue LEDs.

I connected the transceiver to my Solarcon Max2000, a 24ft. antenna mounted about 15ft off the ground, surrounded by trees, and an Astron power supply. Good thinking from Galaxy for putting the microphone plug on the front panel by the way, which I plugged in, then turned the volume knob to ON. It worked! I shouldn't be so negative, since I suspect that most CB radio manufacturers produce the same lever of "quality." I tuned to 38LSB and listened, playing with the clarifier whenever I heard someone calling DX.

[tip]The clarifier is the knob that turns the "Donald Duck" voices you hear on SSB into something you can understand.[/tip]

If you are a safe cracker by trade, you won't have any trouble with the clarifier on the 979. It takes that kind of finger dexterity to operate the darn thing. Before you have a caller "clarified," he is usually done talking.. Aggravating.. The range on the clarifier is too broad. My old President Jackson has a much better clarifier, but of course, that radio has acquired a quasi legendary status in the CB world. With a little practice, you get better at it, but geez!

Compared to HAM transceivers, CBs are noisy... I plan on replacing a few diodes with Schottky Barrier Diodes, and replace an RF amp transistor with a 2sc2999, High Gain, Low Noise model. The procedure is described here; part are on the way (about $1.60!).

I remembered that I should check the SWR before transmitting, which was a perfect opportunity to test the inboard SWR meter. I also plugged in a Workman el-cheapo meter on the antenna output. They did not agree with each other! The Galaxy SWR meter barely moved while the workman showed 1:1.8! I tuned the antenna and got down to 1.6 (probably all those trees..). Oh well. Just keep an eye on the SWR warning LED.. It works (I had a short in one plug); the SWR meter also jumped up. It might not be the most sensitive SWR meter, but it will let you know when you risk frying your final transistors.

It was getting late and the band was dying down when I heard "476" calling. He did not say where he was from, but I could hear him very well, good audio and a signal of 7. I expected him to be within fifty miles of me. I asked him about his location and he said "Jamaica!" I had a low signal but good audio (mike gain turned all the way up). Not bad for a $140 piece of gear. The antenna is everything, mind you, and the IMax2000 did it's part. The Galaxy... I hadn't wasted my money..

The Galaxy DX 979 won't win manufacturing quality contests. It does however work well. For the price, you can buy two and box one up in an ammo can for EMP protection. It is a small price for never being entirely cut off from the rest of the world.


326
Antennas / Building a 2m Slim Jim Antenna.
« on: May 09, 2012, 03:41:07 PM »
I needed a better antenna for my Yaesu FT-270R. My requirements were to find a portable, efficient and easy to build design. The short rubber antenna works fine for me now, especially that I am not transmitting before getting my license. I do want more range however for emergency situations, in case local repeaters are down. My first thought was to make a Yagi-Uda directional antenna. They have a high gain but transmit in only one direction. While this can be an advantage, and I plan on getting one, my go-to antenna needs to be omnidirectional. I found the Slim Jim design to be my best option. It is easily made from soldered copper tubing. All you need is a couple of 5ft lengths of 1/2" tubing, 90deg corners, end caps and PVC Ts. I added an electrical junction box for the feed-point connector, but it might make it more difficult to attach the coax and tune the antenna.

Total length very-top to very-bottom is 58". Width center-to-center is 2". Gap is about 1-3/4". See the Ham-Universe articles (1 & 2) for exact measurements.

It is easy to calculate dimensions for other frequencies:

  • 3/4w : 8415/F-mhz.
  • 1/2w : 5610/F-mhz.
  • 1/4w : 2805/F-mhz.
  • Feed point : 10-20% of 1/4w.

The gap is taken off the 1/4 wave element...

Slim Jim Gap

The PVC Ts need to be reamed with a 5/8" drill bit so that the copper tubing can go through. I used a bit of WD40 to slide them down. Between the two Ts, I epoxied a 1" piece of 1/2" plastic tubing. There is one "H" PVC support assembly on the top portion and one on the lower portion, right next to the end cap.

Slim Jim Feed Point

I am not sure that using a plastic electrical junction box was a good idea for the feed point. Since I have not received my SO-239 socket yet, I must hold off on the electrical connection. My concern is that soldering will be difficult without burning the plastic box. I might have to use sheet-metal screws. Tunig might not be easy either, since the best SWR is obtained by moving the feed point up and down, between 3 and 4" from the very-bottom. Maybe I should have used PVC Ts, like for the two support "H" assemblies. They can be split in half, then the coax soldered after finding the best feed point. Once epoxied, it would look fine. I do like the look of my electrical box though, and if it works fine, I will be happy with the results.

Total building time was about an hour. Everything came from the hardware store, except the SO-239 connector. Soldering turned out to be pretty easy. I sanded the parts and used flux paste before heating up the assembled parts with a torch. Once the parts are hot enough, you put the solder on, which flows in the joint, following the flux. Cost could have been as low as $30, but I spent about twice that much, not counting tools (hacksaw, drill bit, epoxy, solder), which you might have already. If you are starting "empty handed," plan on $100. While it can cost more than a factory-made antenna, you get the satisfaction of building something yourself, which might be actually sturdier than a store-bought model.

Stay tuned for the finishing touches (painting), electrical connection and reception testing.

Thanks to Richard KE5FXU SK at hamuniverse.com for the article!

Update, April 11th:

Finally, I got my SO-239 plug. Drilling the PVC box was easy. I didn't even use my drill press. It only took me a few minutes by hand! Holes are one 5/8" in the middle, and four 1/8" around. I drilled in the middle of the lid, hoping I would have enough leeway to adjust the SWR by moving the contact in the box along the tube. First, as I suspected, I could not get the tube hot enough to solder the center of the coax to the copper tube using my 30w soldering iron. I solved the problem by heating up the tube with a Zippo under it while I soldered on top! It worked really well. I did the same to put soldering points in the box, every quarter inch or so. The zippo was placed an inch from the box. I was worried about melting it, but these electrical boxes are pretty heat-resistant. Sorry about picture quality:

Solder Points

It's a bit ugly, but inside the box anyway..

Feed Box

Reception works great. I was able to listen to a conversation tonight on a distant repeater that I simply could not hear with the HT rubber antenna. I get three extra signal bars with the Slim Jim. I got a cheap VHF/UHF digital SWR meter from Hong-Kong, which seems to work fine, but for the connectors which are of "N" type.

Digital SWR meter

Update, May 1st:

I painted the antenna sort of a flat olive-drab color for stealth. I can easily hoist it up a tree and it blends in very well. SWR varies from 2.4:1 on the lower part of the band, to 1.8:1 around 146Mhz, and remains around 1.4:1-1.5:1 from 146.5 up. I used a ferrite RF choke kit from Palomar Engineers (photo below), which got the SWR down to 1.36:1 around 147.5Mhz. I much prefer the ferrite choke to the coax balun type, which looks ugly and wastes cable.

Slim Jim Connection Box With Palomar Ferrite Choke
 
What I like the most about the Slim Jim is it's sturdiness and that given it's shape, you can hang it from anywhere, as long as you use an isolator to do so. When hanging it, I plug in an "L" shaped adaptor (photo above) to avoid bending the coax.
Update Oct 30, 2012: I have been using the antenna with my Icom IC-271A and it works great, even with the antenna set on the corner of my desk! I do plan on putting it outside on a pole or hoisted in a tree, but haven't had the time. I can hit distant repeaters on half-power (13W) with no problem and get good reports. What I like most about it is that I can take it with me anywhere and not worry about banging it or damaging it. It is easy to hoist up with a string or tape it to a pole. The SWR can probably be reduced by doing a better job at finding the sweet spot to attach the coax. It doesn't even look like an antenna to the untrained eye, which is always a plus.

327
General Discussion / Frequency considerations and introduction.
« on: May 09, 2012, 03:09:47 PM »
I bought my first CB radio in 1984, a Lafayette LM300. I wish I still had it. Ten years later I got a President Jackson. After CB went ?down the drain,? I stopped all radio activity, until today.

I clearly remember twenty years ago, even five. I did not then have any of the concerns I have today. The future was bright with no clouds on the horizon. I don?t think the world is going to end this December twenty first, or next year for that matter. The Mayan who wrote his calendar must have been tired that night, and his wife was complaining about how much time he spent on it, so he probably just thought it went far enough and left it at that.. I am no doomsday preacher.
There is a certain unease among us however. The media is broadcasting multiple disaster and prepping shows. The economy isn?t going better. Five years ago, I had five ounces of gold, bought for less than $1500. Today, those coins would be worth close to $10,000. Only five years later! I am still hitting myself on the head for selling them before the increase. We may wonder why the value of the Dollar and the Euo have not gone down by a factor of six or seven. One only has to watch the news to start worrying.

I have always been the poster child for safety. Yet, I have enjoyed dangerous activities like ultralight flying, cave diving, motorcycle riding, parachute jumping and others, but always prepared and trained properly. The fact that I am here today has nothing to do with chance.

Being prepared for me means being prepared in all areas. I have seen people stocking up food while smoking two packs a day, shooters with dozens of guns who can't run to their 100yrd target, or people with a bunch of medical supplies but no water or any means to purify it. I have seen very few preppers with the means to communicate!

So, I am studying for my HAM licenses (yes, all of them), while enjoying my Galaxy DX 979 CB.

I have thought about HAM bands quite extensively and done a lot of research with an emphasis on emergency use.

For local communications, 2m seems the best option. I would also include a few FRS handhelds to keep track of family members and local friends in your neighborhood. I can't think of anything the 70cm band offers that 2m can't do.

A CB is a must as well, but it should include SSB, to take advantage of the 11m band's ability to skip on the ionosphere, thus allowing very long distances.

I am also intrigued by the 6m band, which at times behaves either like VHF or HF, depending on conditions. It also has the advantage of small antennas, with a half-wave being, well, 3m long! I found an old 6m Gonset Communicator III AM radio on Ebay for cheap, with a crystal for 50.4mhz. That set would probably survive an EMP sitting right in the open! If only someone else around had one...! 6m AM would make a great local frequency, if small and cheap handhelds were available. You would also get skip when the conditions are exceptionally good.

On HF, I am planning on sticking to 20m (14mhz). Lower than that and you run into antenna length problems. You can find cheap QRP kits for that band. I have ordered a small CW only transceiver kit for $30! How can you beat that? 20M is probably the most popular HAM band and would be great to listen to in a national emergency. Moreover, propagation is decent to great most of the time during the day and early evening hours.

In my opinion, better have a few radios for different bands rather than one that covers them all. I do want a Yaesu FT-817ND, but I will have a metal can with a 2m handheld, CB, 6m SSB, 20m QRP transceiver, a handful of FRS handhelds and a few accessories stored inside a cardboard box inside the can, for EMP and water protection. For a few hundred dollars, you can be well prepared as far as radios go. Much less than the cost of a good rifle ;-)

328
General Discussion / PLEASE READ! Welcome to Radio Preppers.
« on: May 09, 2012, 02:11:40 PM »
Information is a vital commodity in a disaster situation. Whomever has any, in the absence of Internet, phone and power services will have a great advantage.

Radio Preppers aims to provide individuals interested in disaster preparedness with an independent tool for the exchange of information about emergency radio communications and preparations. Hopefully it will also help build a community of like-minded individuals who could contact and help each others in times of what is commonly known as 'SHTF' or 'TEOTWAWKI.' Like-minded here means self-sufficient, strong-willed and responsible people. Independent means regardless of nationality, race, gender, political and religious beliefs, as well as unrelated to any organizations. Whether you are a licensed HAM operator, CBer, or simply curious about radio preparedness doesn't matter here.

My motivation for creating this site came from my inability to find an emergency radio club that really wasn't related to some kind of organization, mostly governmental or politically affiliated. Survival is a personal, family or small community affair. I am always suspicious of organizations that plan on telling people what to do for their own good, or else... That said, anti-government rhetoric will not be accepted here. If you don't like your government, vote accordingly. There are plenty of other boads for political ranting. This one is not one of them.

Sign-up, it's free, and stop by once in a while. If you have anything to contribute, please do so! Topics will not necessarily be limited to radio but must be related to disaster preparedness. To avoid spamming, you do need to answer a couple radio related questions; nothing a quick Google search can't answer.

Rules are few: Be courteous. Although some civil political discussions are acceptable, try to avoid them; same goes for religion. Do not suggest anything against the law, or you will be immediately banned.

Please consider supporting this site after joining by subscribing at: Profile > Summary > Actions > Paid Subscriptions. You will get more privileges!

Note that members who do not participate at least once a year will be deleted.

Any suggestions would be appreciated. I hope you enjoy this forum and that it helps make you and your family safer.

Gil.

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