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This is a very exciting episode of Linux in the Ham Shack for us. It's so special, that it's a double episode! That's right, it's like getting two episodes in one. Your hosts (one of them new to the program) discuss winter field day, WxBot, the origin of Debian Linux, SSTV using Linux, OpenSSH security concerns, solving the Rubik's Cube with Linux and a whole lot more. Hope you enjoy, and please welcome our new host!

73 de The LHS Crew

I got my AP510 APRS tracker a little more than a year ago. It kind of worked, but not very well in my car. But after the tracker got a new firmware dated 3 Nov 2015, it has become so much better. Now I can say that it is really useful.

AP510 with original short antenna and telescopic antenna

Apparently, the Smartbeacon function didn’t work properly in earlier versions of the firmware. With some good debugging and error reporting by KC5EVE, Mark, working with the software developer for the AP510, BG6QBV, the annoying errors now seem to be gone. This is all documented in the Yahoo AP510 group.

I have fitted mine with a 16-45 cm telescopic antenna and even when attached to one of the rear headrests in my sedan, the 1 Watt of output power tracks very well.

The map below shows a drive from Telemark, about 100 km west of Oslo, to Oslo with as good coverage as one can expect given the valleys and the availability of APRS digipeaters especially in the western part.

Note the missing tracks east of LA5PPA-1 which are due to a 3.5 km long tunnel, Strømsåstunnelen, between Drammen and Mjøndalen.

I got my AP510 APRS tracker a little more than a year ago. It kind of worked, but not very well in my car. But after the tracker got a new firmware dated 3 Nov 2015, it has become so much better. Now I can say that it is really useful.

Apparently, the Smartbeacon function didn’t work properly in earlier versions of the firmware. With some good debugging and error reporting by KC5EVE, Mark, working with the software developer for the AP510, BG6QBV, the annoying errors now seem to be gone. This is all documented in the Yahoo AP510 group.

I have fitted mine with a 16-45 cm telescopic antenna and even when attached to one of the rear headrests in my sedan, the 1 Watt of output power tracks very well.

The map below shows a drive from Telemark, about 100 km west of Oslo, to Oslo with as good coverage as one can expect given the valleys and the availability of APRS digipeaters on the way.

Both the Baofeng UV-5R handheld UHF/VHF radio and the Sainsonic AP510 APRS tracker come with interface cables with pirated chips. These are clones of Prolific USB/serial chips. Since Prolific has taken measures against this, only old drivers will work with them. That means that one has to stop automatic driver updates as explained on the Miklor site for the Baofeng UV-5R. The same is true for the AP510. This is a nuisance.

I got tired of this and got myself some USB/serial modules from Ebay based on the CP2102 chip instead. The cost was US $1.43 a piece so it should be affordable for anyone. I also got some clear heat shrinkable tube.

It wasn’t too hard to follow the instructions on the Miklor site. I ended up replacing the chip in the original Baofeng serial cable. I’m a hardware guy so I think it is a shame not to see the three LEDs for power, rx, and tx so I used my Dremel to make a 12×12 mm cut-out in the original case, and then I closed it by using transparent shrinkable tube. For a picture, see the top of the first image.

If it doesn’t work the first time, exchange the rx and tx connections and see if that works better. According to this site, the boards can be marked just opposite of what you might think.

The Sainsonic AP510 APRS unit has a cable that on first sight just looks like a standard USB cable, but it also contains such a chip. Here I made a completely new cable without any case.  It is important that 5 Volts also passes through as this is used for charging. The pinout can be found on the site of DJ7OO (use Google translate if needed). I enclosed the board in shrinkable tube which is transparent enough for the LEDs to shine through as seen in the bottom of the first image. The board with the fake chip is found in the middle. 

So now I have interface cables for both units that don’t require me to stop updates of drivers or any other special precautions and it is much easier to program the devices from any PC.

Both the Baofeng UV-5R handheld UHF/VHF radio and the Sainsonic AP510 APRS tracker come with interface cables with pirated chips. These are clones of Prolific USB/serial chips. Since Prolific has taken measures against this, only old drivers will work with them. That means that one has to stop automatic driver updates as explained on the Miklor site for the Baofeng UV-5R. The same is true for the AP510. This is a nuisance.

I got tired of this and got myself some USB/serial modules from Ebay based on the CP2102 chip instead. The cost was US $1.43 a piece so it should be affordable for anyone. I also got some clear heat shrinkable tube.

It wasn’t too hard to follow the instructions on the Miklor site. I ended up replacing the chip in the original Baofeng serial cable. I’m a hardware guy so I think it is a shame not to see the three LEDs for power, rx, and tx so I used my Dremel to make a 12×12 mm cut-out in the original case, and then I closed it by using transparent shrinkable tube. For a picture, see the top of the first image.

If it doesn’t work the first time, exchange rx and tx and see if that works better. According to this site, the boards can be marked just opposite of what you might think.

The Sainsonic AP510 APRS unit has a cable that on first sight just looks like a standard USB cable, but it also contains such a chip. Here I made a completely new cable without any case.  It is important that 5 Volts also passes through as this is used for charging. The pinout can be found on the site of DJ7OO (use Google translate if needed). I enclosed the board in shrinkable tube which is transparent enough for the LEDs to shine through as seen in the bottom of the first image. The board with the fake chip is found in the middle. 

So now I have interface cables for both units that don’t require me to stop updates of drivers or any other special precautions and it is much easier to program the devices from any PC.

This transceiver looks like it should be possible to duplicate. A neat design. I think this connects via a USB socket so the PC acts as a node for digital modes like DSTAR.

See http://unsigned.io/forum/viewtopic.php?id=2

The picture on the left, from APRS.fi shows the level of coverage by APRS iGates in Wasdale (A lake district valley that is home to Scafell Pike, England’s tallest mountain). You can see that the coverage is fairly limited to heights above about 400m. That really isn’t very good.

I had walked from the road north of the river Irt and up what was a quite steep hill to Whin Rigg. What makes the lack of gates even more disappointing was that there is a clear view of the Isle of Man as well as southern Scotland as you move up the ascent.

So why is it so bad? Well the geography doesn’t help. Like many hilly areas the western lakes is a series of valley that lead out to sea so when you are low there is not much scope for RF to go anywhere. this also explains the patchy mobile phone coverage. Another aspect was the stock antenna on my vx-8. It really isn’t that good compared to other larger aftermarket options.

So what? well first off we hams aren’t the only people to us APRS or a similar protocol. The mountain rescue also use a proprietary system. They must suffer with the same lack of coverage despite a sizeable array at the head of the valley.

So what do other areas use? do they use APRS in hilly areas? are there low cost self powered digipeaters or iGates about? is APRS out-dated now that digital modes are so popular (not here mind you)? I’d like to know simply because I like APRS and think its a under utilised system here in IO84, perhaps elsewhere.