More changes to mobile APRS

After much consideration I decided to keep power to the GPS16 receiver permanently. The reason is my intention to eventually install a car PC. The second is that I would like to come up some sort of arrangement that will activate the APRS should the car end up being driven by someone other than me and parked where it might not be easy to find. This would probably involve some sort of device that I would carry and be detected. If the car is started and driven without the device being detected, the APRS turns on and remains on until I intervene. The device would probably be an RFID or somesuch. The car PC would also log all GPS activity at all times.

To allow for GPS connectivity to a PC, I made and installed a splitter between the RS232 GPS and the OpenTracker+. The splitter simply feeds RS232 signal from GPS to two outputs. This was tested with the APRS running and the netboook connected through a 4 port USB-to-RS232 device at the same time and it worked fine. I will need to make sure that the car PC and OT+ can't both talk to the GPS at the same time or something will collide. There shouldn't be any need for either to TX to the GPS anyway.

Still looking for a VGA LCD display that can be powered from 12V, around 10". I could buy an old laptop and hack the display to extend it from the body, but I'm not sure what cable length I could use before it becomes unstable. I suspect it wouldn't be much. I refuse to install an inverter just to power a mains-powered LCD! There are some in-dash displays available but the price is just way over the top for a project like this and besides, I can't install in-dash in the work vehicle.

Dollar

Hey, if you are advertising something on the internet then have the courtesy to state what dollar you are using. We don't feel like searching your web pages for 20 minutes to find out what country you are based in (and even that is still guessing) If your web site its www.something-or-other.com then you could be anywhere in the known universe. The internet goes that far. Just so you get it, here a list of countries that use dollars:

Australian dollar
Bahamian dollar
Barbados dollar
Belize dollar
Bermuda dollar
Brunei dollar
Canadian dollar
Cayman Islands dollar
East Caribbean dollar
Fiji dollar
Guyanese dollar
Hong Kong dollar
Jamaican dollar
New Zealand dollar
Namibian dollar
Rhodesian dollar
Singapore dollar
Solomon Islands dollar
Taiwan dollar
Trinidad and Tobago dollar
Zimbabwe dollar
United States dollar

Better still, have a gadget on the web page to let us change what currency your prices are displayed as. Plenty of websites do it. They are probably getting our business instead of you.

Aussie Aussie Aussie

Happy Australia Day from AX6UFO
Installing everything properly. Everything was held together with duct tape and cables running through doorways. Looking at buying a cheapie Nagoya NL-770R antenna which should get the 5 watts out a little better than the mag base ¼ wave. The NL-770R appears to be a clone of the Diamond NR-770R. I can buy three of these cheapies for the price of one locally purchased Diamond.

Connect PX-777 to OT+ using free earpiece

Here's how I connected my PX-777 to the OpenTracker+ using the free earpiece/mike. Your earpiece may be different. Use this information at your own risk. If you can't see the whole image then just click on it.
The easiest way I found was to crack open the mike/PTT thingie using a pair of pliers or similar (it came apart quite easily) and then desolder the wires from the mike, PTT button and wire leading to the ear piece. The wires are coloured as in the diagram. The 'copper' wire was just that, no colour to the insulation.
This method is a lot easier than cutting the cable off and trying to tin the individual wires. This type of wire can be tricky to tin. I mounted the DB-9M inside a standard shell. Make sure the wires are restrained properly otherwise it's all going to fall apart. I put several layers of heatshrink tubing over the wires as the restraining clamp would not have enough to clamp down on.
I also built a voltage regulator to power the PX-777 without batttery. I used an LM317 TO-220 in the normal configuration built on some veroboard (stripboard). I included the input and output capacitors as well as the reverse protection diodes.
After measuring the voltage of the fully charged battery, I found that the radio is happy to run from 8.2 volts, so I set the LM317 to that. I probably could have used a 7808 regulator but I didn't have one.
I powered the PX-777, OT+ and GPS16-HVS all from the regulator and it worked fine on a 30 minute journey. I wouldn't recommend transmitting with the radio for normal QSOs, especially if the regulator isn't on a decent heatsink like mine isn't. The regulator can handle the occasional 1 second data transmissions but it probably won't like continuous duty. I found some information on the battery eliminator you can buy for these radios and they are rated at 3 amps. I doubt the radio draws 3 amps though. I probably should measure it some time...
To connect power to the radio without a battery I am using nippy clips (small insulated alligator/crocodile clips.. whatever colloquialism you want use) temporarily until I find a better solution. I might end up just getting a battery eliminator anyway.

More PX-777

Can you program a PX-777 with Icom or Yaesu cables? No. If you have a programming cable for other radios that is 'one wire' (ie the TX and RX comms travel down one wire) then they will not work. Later Icoms and Yaesus seem to use these. Most Chinese radios seem to be compatible with Kenwood and use separate TX and RX line. Some earlier Icoms and Yaesus do use two wire but I don't know if they are true RS232 or are TTL. Let me know.
On the plus side, you can use the USB TTL adaptor that I mentioned in the previous post on some (maybe all?) newer Icoms. All you need to do is join the RX and TX lines together on the TTL side and add a suitable lead. I've done exactly that with the adaptor I mentioned connected to an IC-706MKIIG and an IC-208H. You need the software as well :-)
I'm looking at why I can't do the same with Yaesu. The way the TX and RX are tied together seems to be different. Probably the same reason why I can't use the 3rd party Icom adaptor I bought on a VX-3R or FT-1802.
I also forgot to mention in my previous - when programming the PX-777, you don't need to set the radio into a particular mode. Just turn it on, plug the plug(s) in and start communications.
Found the issue with the unit not charging in the charger. The charger has two projections, one either side that slot into grooves on the battery. It's possible to insert the radio so the projections are completely behind the whole unit. There's way too much play in the bay. Just pay attention to how you push it in.
I plan on playing with this radio for a few days as a regular handheld for voice just to see what they are like. So far the
Pros: Seems to get out well. Software is legally free and can be made to work. All documentation including service manual and informtion for interfacing is publicly available. Speaker volume is definitely not lacking! (See cons) Kenwood handheld accessories are interchangeable. Easy to interface for packet/APRS. LiPo battery. 12v charger for easy adaptation to mobile and portable use and uses a standard 2.1mm DC plug. Solid contruction. Plenty of information on line how to disassemble and reassemble.

and cons: Antenna connector gender isn't logical. Volume control goes from soft to LOUD very quickly. Software, although free, is poorly written. English voice announcer could be made by someone who speaks English without accent (my wife's NavMan does several different English accents and US American) The English manual needs translating to English. No biggy but the selectable colours for the LED illumination are just weird: Violet, blue and orange. Violet? Some obvious functions are completely omitted from the manual; eg How to get it to display channel tags instead of the frequency. Stumbled upon that one on tha interweb. Can't plug in a standard external speaker - get a 3.5mm to 2.5mm adaptor (they do exist; my Laser DMP is the same) The PTT button is very touchy. I sneezed a while ago and three callsigns said "Gesundheit." OK slight exaggeration but would need to modify for day-to-day use. Was the same for my FT-1802 mike.

Sorry about the typing... I'm on teh netbook.

Programming the Puxing PX-777

If you are thinking about buying one, or have one but haven't programmed it through your PC, it can get messy.
To program a PX-777 from PC you need four things. A PC, a PX-777, a programming cable and some software. Your PC will need to be able to run windows programs. I haven't tried wine. I suspect that 98/Me will work OK - I plan to try it later just for the hell of it. Under Windows XP you might have problems but it can be fixed. If you are using Vista then you can fix that by upgrading to Windows XP.
The programming cable can be purchased online. You can (apparently) also use cables designed for Kenwood handhelds. As a ham you might want to make your own. It's not that difficult. If you have a standard RS-232 serial port then you need to convert to TTL level signals with a MAX232, MAX 233 or similar. There's a hand drawn circuit here. Make sure the lead to the radio is as short as possible. Although this signal is usually called "TTL RS232", it is not really RS232 and there will be signal loss over long cables. It will also be prone to interference.
Serial ports aren't that common any more, so you might have a USB converter or want to buy one. You need to establish what comm port it becomes, and you will find that the port number might change from PC to PC and even from USB port to USB port! Open the device manager and select the PORTS item. Look for your port there. The next problem is that some of the software allows you to select only comm port 1,2,3 or 4. (USB adaptors usually end up being comm 5 or higher). This is very poor programming. You can get around that by reassigning the comm port of your device. As administrator, right click on the port in device manager, select Properties, click the Port Settings tab, select the Advanced button, and use the dropdown to select a new port. Hopefully you will find one of the first four free. After you close all the windows you just opened, you might need to unplug the device and replug to gain access to the new port.
Another option which is easier than making a MAX232 interface is to buy a USB to TTL converter. I bought a Sparkfun adaptor for $AUD 17 in Perth. Shops that sell Arduino or robotics might carry these. Also look here. This adaptor has a USB mini-B socket one end and a six pin SIL socket the other end. An A-to-mini-B USB lead is required, such as used on most USB hard drives, some media gadgets and some phones. The SIL connector is standard 2.54mm pitch and has TX, RX, GND, +5V and two handshake signals. Connect the GND, TX and RX the same way as in the diagram mentioned above. Keep the wires short! I bought a 3.5mm stereo plug and 2.5mm stereo plug from an electronics store and used some shielded twin cable connect it together. Did I mention short wires?
As for the software... well Puxing make great radios. If you look here, you will find some programming software. See if you can work out which one to download. Yes, it is (as of this writing) "V6". If you use windows XP or any of the other NT versions and are like me then you log into the OS as a regular user (limited account) and not as an administrator. If you do the latter then suffer! The problem with some programmers is that they aren't really programmers. They just write programs. And usually while they are logged in as an administrator. They never test their software as a user. If they did, they would see that they make the same old mistake time and time again. Save files in the application install directory. Why is this stupid? Well you can't write into install directories if they are in a system directory unless you have rights. Eg admin rights. Files like settings and other user stuff are supposed to go in the user's home folderer, preferably in the application data folder which is what it's there for. This also means you can have multiple users on one PC without each stomping on the others' settings. But no, the Fuxing software tries to save settings in "C:\Program Files\PX6IN1\" which it can't do as a user, so the software is stuck with the default settings. If you have a PX-777+, the default setting is to use Chinese language.
How to get around this? Well you can install the application to a folder that anyone can read and write, or you can install the default directory and then copy the whole folder somewhere else. I chose the latter.

1) Install the software as normal (as admin of course).
2) Look at "C:\Program Files\PX6IN1". Copy the PX6IN1 directory to a USB thumb drive or your 'My Documents' folder or some other location you have rights to. 'Shared Documents' is another good place. This is where I keep all unfriendly applications. There's plenty of them.
3) Uninstalll the software. You have a copy remember?
4) Run application from thumb drive. Hey presto, language is now English. The application has the default MFC icon (blue, cyan and white). They could even be bothered to install their trade icon in the application.

When you run the application, select "PX777/328 CH128 +2TONE" for the PX777+. That will be remembered for next time you run it. Next, make sure you set the comm port - Click on the "Port" menu. It defaults to port 1 and is NOT remembered for next time. Jeez. Next, click on the "Program" menu adnd select "Read from radio." Click on the Start button. If that works immediately then you are ready to roll. If it doesn't work then you will need to check that your cable is correct and that you have selected the correct port. Also make sure you have selected the correct model of radio... it probably won't work even if everything else is OK.

Puxing PX-777 plus

The PX-777+ arrived today. $AUD 83 including shipping from HK. It took five days to arrive which is not too bad for 'including shipping.' KB2SRH has a good youtube of it here.
Came with a free earpiece mike thingamy. Great! This will hack nicely into the OT+.
The manual is the typical Chinese translated into English by someone who only speaks Lithuanian. Fortunately I only need to program one simplex frequency into it. And I learned AngloCinoLithuanian during my service in the Foreign Legion.
The quality is what you would expect for an 83 dollar transceiver... the battery doesn't quite sit snuggly against the radio. The charger doesn't work when the radio is inserted. It works if the battery is inserted by itself. That's not going to work too well for an unattended APRS setup.
The antenna is an SMA but the opposite gender to, say, a Yaesu VX-3. In other words you can screw the PX-777 antenna into a VX-3 antenna. This also means that the tiny and fragile SMA pin is in the radio, just waiting to be bent or broken. The pin should be in the antenna. If you break the pin, you throw the antenna away. I bought an SMA to BNC adaptor a couple of days ago so that will sort that out. Loctite will sort it out even more.
Need to sort out an antenna. I'm using a mag base with a modified ¼ wave so it will almost fit under the car port. There's a twang as it hits a support beam. Also, it seems that I'm not making it into any digipeaters for half my journey to work using 5 watts. I might have to look and a 3db (or better) antenna which definitely won't fit under the car port. This means another antenna up the back of the car.
I'm considering doing away with the PX-777 LiPo battery altogether and running it from the car power via a voltage regulator. 7.4v will probably mean an LM317 or similar. The OT+ and GPS can run from 7.4v as well. That could save a lot of messy wiring.
I'm also considering breaking out the RS232 signal from the GPS to plug into a laptop or car PC. This would allow me to log trips. OpenStreetMap is very sparse in my locality. There's also the option to run nav software. I have everything I need to make a low power car PC, except for a display. I need a VGA LCD that can run from 12v that doesn't require funding from selling my first born.

Use a valid symbol for APRS

aprs.fi doesn't like certain overlay symbols. For example a secondary Van with an alpha overlay (eg Uv)
Secondary Box with alpha overlay is OK though. Apparently the next version of APRS will support a much broader selection of symbols that won't break the holy UIView