Dan Dawson’s Updates

On Saturday morning I headed over to the monthly Electronics Flea Market over at the De Anza College parking lot.  My main reason for going was to pick up a few more of the $1 LED Keychain flashlights I got there a few months back, mine broke and Ellen wanted one.  Of course I wanted to check out the other “toys” there as well!

On the last row just as I was getting ready to leave I saw a brand new Mirage B-34 linear power amplifier sitting on a table.  They are hooked up in-line between a 5 watt handheld radio and the antenna, boosting the signal output up to 35 watts.  I’d never used one, but I know I could definitely benefit from some additional power.  Thought about buying it, the price was $40, then wandered away.

Before leaving, I pulled out my iPhone and checked Google and eBay for the prices of these things… saw prices ranging from $89-$120 for them, so $40 was a great deal, figured I could just sell it and make a profit.

Well, as soon as I got home I quickly talked myself in to at least “trying it out” which led to a long afternoon of playing with cables, connectors, and soldering irons.  I checked the max power consumption of my cigarette lighter adaptor for the car, saw it was good enough, so I soldered a lighter adaptor to the power cables on it.  Bought an antenna cable at radio shack, cut off the end, and soldered on another PL-259 to the end of it and got everything running.

I pulled out my second HT so I could test the audio differences with it on and off, and quickly learned about desensing a receiver… The HT would hear the “roger beep” style tone of the repeater, but I couldn’t hear the audio of my own transmission at all.  I even separated it from the antenna a ways and had it recording on my laptop so I could review the audio later, but still wasn’t able to get much.

It wasn’t until tonight when I was talking with Craig, W6WL, and he told me it was definitely just desensitizing the receiver, and after a quick test with him we proved both radios really were transmitting properly.  Sitting in my driveway with my mag-mount antenna he said he could receive me about 70% signal.  Then I flipped on the 35 watt amplifier and he said he could hear me at 104% hehe.  We chatted for a bit and my signal was quite strong to him, so long story short, I’m very pleased with my purchase!

In addition to that, while I was working on getting that wired up, I also did some additionall installation to get my RTrack APRS tracker wired up in a more permanent installation.  I’ve got it running to my old hershy kiss mag mount antenna.  We’ll see how often I make it to a digipeater now, and if I don’t get great results, I may toss the 35W amp inline for that transmitter for a little while and see if that brings about great improvement.

The tracker of course was primarily for the airplane, and I think the lower power of the unit will work just great.  Driving around this mountainous tree filled area with a small antenna some extra wattage might be beneficial!

I work for a non-profit organization and over the years I have spotted more and more of our staff groups using Family Radio Service (FRS) radios as a part of their jobs. While I knew it is an unlicensed band, I also assumed that business use would have been prohibited since it was called the “Family” radio service.

I inquired with two of our staff who probably authorized their purchase and use to see if they knew the legalities of it, and both admitted they were not absolutely sure if it was legal or not, but also commented on the truth that they are such short range devices it probably would not cause any harmful interference to any other users of the frequencies.

I decided to do a few minutes of research which I shared with them, and now I also share with you in case your might also be interested.  The short story is… yes, it’s legal. 

The longer version follows:

The last sentence of the FCC introductory paragraph on the service is of most interest to us in this case:

Family Radio Service (FRS) is one of the Citizens Band Radio Services. It is used by family, friends and associates to communicate within a neighborhood and while on group outings and has a communications range of less than one mile. You can not make a telephone call with an FRS unit. You may use your FRS unit for business-related communications.1

It does appear in 2002 that a petition2 was given to the FCC by the ITA3 requesting business use be prohibited from the frequencies, but with quick review of the FCC comments on that petition it looks like they dismissed it as a money-making attempt by business band radio manufacturers :-)

So for businesses who do use FRS as a part of their day-to-day operations I would just recommend always keeping in mind that this is shared radio spectrum, and if ever our use interferes with anyone else’s use of the frequency we need to be willing to move and not assert any “rights” to those channels. Personally I believe that if push ever came to shove, I think families and occasional users have more right to “family” spectrum than do businesses, but currently it is completely legal to use it.

My only other brief comment is that if you ever create an emergency communication plan or disaster plan, I recommend including FRS Channel 1 with Privacy Code 0 (no tone transmitted) as that frequency to be used for staff responding to such an emergency.

Channel 1 is casually recognized across the country as the emergency frequency4, and turning off all privacy tones ensures more radios from various manufacturers would actually be able to communicate with each other since the tones selected don’t always match across brands.

If you have any additional information or correction to this post, please let me know in the comments, I’d be glad to update my text with any details you may point out.

I’ve intended to do some comparisons between the APRS Tracker options out there to decide which one I might purchase and use. My primary uses would be for tracking my car and aircraft, as well as possible use for hiking, mountain bike riding, etc. Some day down the road it might be integrated in to high altitude balloons or radio controlled aircraft, etc.

So for most all of those applications, small size, light weight, low power consumption, and a simple package are the preferences. Currently I use a Kenwood TH-D7 with a Garmin GPS III+ when I need to do APRS. That ends up being a mess of wires by the time I’m done… so I’m hoping for something simpler, and preferably with a dedicated frequency agile 2M radio.

The device that got me started on this search was seeing the recent release of the RPC Electronics RTrack tracker. Small size, good looking package, built in radio, programmable to have different profiles, smart beaconing, etc. This unit includes the 500mW Frequency Agile 2M transmitter, APRS Modem, and GPS, all for a price of $250 plus shipping.

Next would be the Byonics MicroTrak devices. They have versions from 300 mW up to 10 Watts. Nice to have some options there! For aircraft use, I think the 300 mW would be just fine, but even with my TH-D7 putting out 5W, I know my APRS coverage in the car is pretty poor in my area, even with an external antenna. So maybe I should go with a higher power unit. Once of the nice things is you can add an amplifier to their lower power versions if you change your mind later. The costs for these vary between $105-$180 for the pre-built versions.

And with all of those, you’d need to add a GPS to the package such as the Byonics GPS1 or Byonics GPS2 for $56 or $69 respectively. So this places the least expensive operational unit at $161, and the range of units from $161-249.

For all of the units I’m initially comparing, I’m not yet looking at if they need antennas, extra power supplies or voltage regulators, batteries, etc. The MicroTrak does offer as an option a voltage regulator, the Micro-Volt 12 that will run from 12-24 volts, so that would be great for car and aircraft use.

I’m going to re-visit this post as I look further in to things, so check back here for updates. But at first glance… I like the simplicity and “sealed package” of the RTrack, everything is in the box. But if I built a box for the Byonics system, for approximately the same price I could have the option of 10 Watts. So it looks like I need to look further in to the differences between the TinyTrak3 features and the OpenTracker 1+ software and options. If I built a box for the Byonics I could include room for batteries.

I got the phone call on March 28th from Ham Radio Outlet in Sunnyvale that my radio was back from repair from Kenwood. Having experienced a bit of “radio withdrawl” even though I don’t talk a lot on it, I ran right over there on my lunch break. Picked up the radio, plugged in my programming cable in the car, and got all of the frequencies restored with no problems. Nice to have everything back to normal!

The other interesting news was that Mark Bronson (KI6FEA) and I finally made contact via radio. He’s over in the San Jose/Alviso area, and we met up on the K6FB Castle Rock repeater late one evening. Hopefully that encourages him in to the hobby at least a bit :-) Then after church we talked via simplex on our way to lunch and then over to his house.

We talked a lot more about APRS tracking for our aircraft that afternoon, and I’m putting together some of my thoughts on the options available to us regarding that shortly. Primarily I’m going to compare the options of the RPC-Electronics RTrack, Byonics TinyTrak3Plus, Byonics MicroTrack, or just using the Kenwood TH-D7 with an external GPS.

My goals are for something small, easy to set up, low power consumption, fewer wires the better, low cost, and to adjust it’s beaconing rate depending on speed if possible.  I’ll review the listed trackers above, look for others, and report back on which one I’ll probably end up buying. I’ll be sure to refer to this page to see which ones look the most interesting ones to take a deeper look at.

I was able to run over to Ham Radio Outlet in Sunnyvale today at lunch and asked if they had any ideas.  We were going to try another cable (start with the cheapest link in the chain right?) but they only had default Kenwood cables and Mark has my serial adapter.  So… we tried my cable and laptop with the demo model in the case… and as I expected, it worked just perfectly.

So now we knew it was my radio, and after learning they don’t do any repairs in the shop, we went ahead and filled out the paperwork and they’ll ship it off to Kenwood since it’s still under warranty.  I asked if they had any estimates on how long it would take, and he simply said they’d call when it came in.

I may grab my old radio back from Mark this weekend if we meet up so I don’t have to give up this radio hobby cold turkey ;-)

I’ve been having a lot of fun playing with my Kenwood TH-F6A over the past months, been using it more to get on the air recently. I even joined ARES, Santa Cruz County Amateur Radio Emergency Service. I’d listened to their nets occasionally over the years and after I heard Cap Pennell (KE6AFE) talking with someone about the new sign-up form, I figured I could easily both help with testing the form and get myself sign up at the same time.

But the bigger update is that I’m having radio troubles! I often am adding, changing, or re-ordering frequencies on this thing, and starting last night, my data cable is no longer working.

As I’ve mentioned previously I use MacMemoriesManager on my MacBook Air. It’s been working great all this time, but now the software keeps reporting that it can’t find the radio. First I tried a Menu Reset on the radio, then a VFO reset, and as a last resort I tried a full reset. Now I’ve got a blank radio and no way to program it via the cable!

If I get a few minutes tomorrow at lunch I’m going to try to run over to Ham Radio Outlet in Sunnyvale and see if they can take a look at it. I noticed that the double plug seemed like it was a bit firmer going in, so my guess is one of the small internal contacts inside the jack has bent out of position.

For months I’d been seeing pictures and reading stories about the Arduino, the short description from their website is:

What is Arduino?

Arduino is an open-source electronics prototyping platform based on flexible, easy-to-use hardware and software. It’s intended for artists, designers, hobbyists, and anyone interested in creating interactive objects or environments.

So before Christmas, Ellen and I were talking about gift ideas for each other and I went ahead and let her know that the Arduino was something I was interested in. She was willing to let me open it early, but I waited until Christmas anyways which gave me plenty of time to research it further online.

I have been really impressed by the platform, and by the programming interface to it. The software comes in Mac, Linux and Windows flavors so that covers just about everyone who would want to try it out. I ordered the Adafruit Proto Shield from Adafruit Industries. Since I bought that as a kit, I had to dig out my soldering iron and refresh my skills a bit.

In preparation for that, I’d recently completed building a MintyBoost kit from from ladyada.net. The MintyBoost is a battery charger for USB devices that runs off of two AA batteries. When I went to MacWord this year, I’d played with my iPhone in the car all the way up and ran the battery dead, so that helped convince me that having an external charger for it that ran off of batteries would be a nice thing to have.

But back to the Arduino… my first step was running through the tutorials over at ladyada site. They were really well put together and take you from the “Hello World” of physical computing, the blinking LED, through the use of switches and more advanced programming and logic.

My first sketches were just blinking LED’s at different speeds. Then I made an LED “breathe” like a sleeping Macintosh. Then I added in a switch and would make it blink or breathe. Played around with digital and analog inputs, tried out some sending and receiving of IR signals. One of the fun ones I did there involved pointing any IR remote control at the arduino to toggle an LED on and off again.

Other silly sketches were variations on the Night Rider light bar, I programmed one from scratch, then found better examples online that were smoother in appearance. I’d seen people trying POV or Persistence of Vision projects, so I downloaded a sketch and had it say Ellen’s name as you waved it back and forth in a dark room Won me some points with the wife there ;-)

I’ve playd with RGB LED’s making them fade in to all the various colors, worked with a 7 segment LED to count from 0 to 9, worked with sending and receiving serial data via the USB port, started working on building a VU Meter (to be used for audio levels, lighting levels, water temperature, etc)

I keep planning on taking pictures, posting code snippets, etc, but I figure it might be better to get in the habit of posting anything and working on the details later. If you want to see any of the source for any items listed here, just let me know. More to come soon.

After quite a bit of reading reviews and looking through catalogs, and viewing the TH-F6A Instruction Manual, I finally settled on the Kenwood TH-F6A as my next radio. Well, actually, it’s “Ellen’s Radio” (KI6FEB) but she and I both know I’ll play with it a lot more often!

Since we only had my one radio, the Kenwood TH-D7, we never have talked to each other on the air, and I really wanted to get at least a basic setup going for emergency communications. I would like her to have a radio in her car so that if the big earthquake happens, at least we’ll have a chance of using radio to communicate.

So far I’ve been really impressed by it, very small size, I can tell it is well built, audio quality seems very good, and I haven’t been on the air with it yet but that will come soon enough.

One thing I really liked about having another Kenwood is I was easily able to transfer the memories from my TH-D7 to the TH-F6 with little trouble! For the D7, I’d been using a Keyspan USA-19HS to USB port, and connecting the Kenwood Data Cable to the radio. I was using MacMemoriesManager on Mac OS X with my 12″ Powerbook. Before I even got my F6 I ordered a USB Programming cable for it from an eBay store called qMall.

I knew there were no Mac drivers supplied with it… but I had faith, and my faith was rewarded with a quick search online. I quickly discovered the cable used the pl2303 Serial to USB chip, and that led me to the SourceForge project: PL2303 USB to Serial Driver for Mac OS X. I have noticed that Apple has a link to that same SourceForge project as well.

I struggled a bit, it was appearing that MacMemoriesManager couldn’t communicate with the radio. Of course I don’t ever read the manuals, so I struggled for a bit trying various options, baud rates, ports, etc until finally I wandered through the menu and found the secret option. Since the TH-F6A doesn’t have a separate PC port, they use Menu Number 9 “SP/MIC JACK” to determine the SP/MIC jack function. It includes the options of SP/MIC, TNC, and PC. I flipped that to PC and the frequencies started copying right away.

I was able to copy all of the D7 frequencies to it, and over the next days I’ll figure out how I want to organize all of the frequencies in to different groups and such. It’s great having the wider receive range, I can pick up AM broadcast, CB Radio, TV stations, all of the aviation band, etc. That was one reason I chose it, I won’t have to carry my Uniden Bearcat 200XLT scanner as often anymore.

In other radio related news, one of the cool tricks I learned last night at the San Lorenzo Valley Amateur Radio Club meeting was from KA6MAL about a system he built. He’s got an APRS infopeater in Boulder Creek and has it set up so if you send a properly formatted message to it the system sends you a message back with the ASOS (Automated Surface Observation System) weather for the airport of your choice.

For the specific details and permission of how to use it, get in touch directly with KA6MAL, but the summary is you format an APRS (Automated Position Reporting System) message query to his infopeater callsign and SSID with a message of “?” for information on the system, or “?AVWX KWVI” for example to receive the Aviation Weather report for the ICAO airport identifier KWVI (Watsonville Municipal Airport). When you send that, his system replies with an “ack” and then passes along a report like this one:

082253Z AUTO 24007KT 10SM CLR 19/12 A2992 RMK AO2 SLP131 T019401{al

One of the downsides of either APRS or the Kenwood TH-D7 is that the TNC has a limit of 45 characters before it cuts off the message. If it’s a limit of APRS or common amongst other radios, it would be nice if Kamal’s system would break the packet at 45 characters and send a follow-up message with the remaining information.  The 45th character is after the “k” in “RMK” … generally the useful information is before that, but if the remark is that the station is unreliable or out of service… that would be a key piece of information!

I’m not sure how often I’d be able to use it, but when you need it, you need it! If nothing else I love seeing more practical uses of APRS and amateur radio! Now it has me wondering what other fun information we might be able to get access to via APRS?  I’ve seen earthquake data broadcast before, it might be really neat to query the infopeater and have it respond with the USGS data on the single most recent largest event in the last hour for a given state.

Either way, keep up the great work KA6MAL and thanks for sharing the information!

This morning I headed over to the Electronics Flea Market at De Anza college and it was definitely worth the trip over. I arrived a bit “late” at 8:15, apparently this thing starts at 5 am and most of the “good stuff” is gone by 7 am. Even so, it was neat to see the assortment of electronics equipment, computers, disk drives, military rations, oscilloscopes, radios and antennas. I could tell there were some really good deals on some items, but the few things I did ask about were a touch overpriced, but with a bit of bargaining I’m sure they would have been acceptable.

I ended up not buying anything there, but then Mark and I headed over to Scanners Unlimited in San Carlos after seeing their ad displayed on Fire Dispatch. The owner of the shop was very helpful, it was great to see his collection of vintage scanners and radios, as well as take a look at some of the new scanners and transceivers on the market. He had obviously been around the hobby a long time and knew the answer to just about every question I asked him. After a brief discussion of the options available for magnetic mounted dual band antennas, I went ahead and made a purchase of a Larsen Antennas W2/70B whip with the NMO2/70BCO coil and a Maxrad Black Magnetic Mount w/12′ RG58A/U, PL259 Connector.

My old antenna was just not doing what I hoped it would and felt I wanted a bigger antenna to try to grab some additional signals, and it sure seems to have done the trick! I will do some testing later comparing my rubber duck, my old antenna, and the new Larsen, but I know as soon as I plugged it in I was getting more APRS packets than I knew what to do with, and as soon as I broadcast my own packet I got two copies back which is great news, recently from home none have been making it out. And I confirmed they did make it out to an iGate in the end, both FindU and Google Earth showed the packets I transmitted, looks like my APRS troubles may now be greatly reduced :-)