I was back on air fairly quickly when I accidentally ended up with one of VK6ZUK Danny's spare OT+ units. Thanks for letting me keep it for a while. Meanwhile I ordered a couple of spare microcontrollers and some other stuff. At $USD7 per microcontroller it wasn't such an expensive blunder after all. It also highlights why you should always save a copy of your configuration to disk. After fitting the microcontroller, a quick load from file and write to device and you're back to normal.
The other 'stuff' I ordered was a couple of OT+ SMT (surface mount technology which equals REALLY SMALL UNIT), a GP525 tiny GPS receiver module (designed for internal use) and an experimenters solderless breadboard (I can buy these locally but importing them from Argent in the USA is cheaper!)
Now all I need to do is see if I can fit the OT+ SMT and GPS into the battery compartment of the PX-777 handheld. I have a hammer. The other thing I like about these is that the telemetry inputs are a lot more flexible than the regular OT+ or the Tracker2. It's just a shame that the documentation is very poor.
31 October 2010
03 October 2010
VK6UFO-9 downgrade...
For some reason my mobile APRS wasn't getting out. After some fooling around I found that TX audio wasn't making it out of the OpenTracker+. Even stranger, it wasn't going out until I connected an amplified speaker to the signal where it started working.. and stopped when I removed the speaker. Looks like one of the divider resistors has a bad solder joint or something. I'm not sure because I had to disconnect the power to the GPS receiver (which is injected through one of the JP links) to get at the audio test point. When I reconnected the GPS power (8 volts) I plugged it into the output of the 5 volt regulator by accident. The regulator survived no problem. The 5v micro-controller, however, had a myocardial infarction. That's a heart attack, not some sort of kinky sex act. All the LEDs lit up and the PTT was on permanent TX. That was one dead black caterpillar. Thanks to Danny VK6ZUK for a loaner until my order for more OT+ and micro-controllers comes in.
I've also ordered from Argent Data a tiny OpenTracker+ (SMT version) and an even tinier GPS receiver module. I hope to make a portable all-in-one unit by fitting both into a battery eliminator for a PX-777 handheld radio. These things replace the battery, are mostly empty space and offer around 7.5 - 8 volts which will power the tracker, which will in turn power the GPS receiver. With a little luck, a smaller generic 7.4v LiPo battery will fit inside along with the other stuff and the radio will become a tiny self-contained portable APRS. A smaller battery should do since the duty cycle is quite low. There's quite a bit of hope involved at the moment.
I wonder if a Tracker2 board would fit inside an FT-1802.
I've also ordered from Argent Data a tiny OpenTracker+ (SMT version) and an even tinier GPS receiver module. I hope to make a portable all-in-one unit by fitting both into a battery eliminator for a PX-777 handheld radio. These things replace the battery, are mostly empty space and offer around 7.5 - 8 volts which will power the tracker, which will in turn power the GPS receiver. With a little luck, a smaller generic 7.4v LiPo battery will fit inside along with the other stuff and the radio will become a tiny self-contained portable APRS. A smaller battery should do since the duty cycle is quite low. There's quite a bit of hope involved at the moment.
I wonder if a Tracker2 board would fit inside an FT-1802.
VK6RN-13 upgrade
As I said, the Argent Data Tracker2 has finally become available again. I ordered one for myself as well as for HARG. I finished setting it up as a fill-in digipeater late Friday afternoon after running for a couple of days as a full digi. As a full digipeater it was performing quite well but is quite unnecessary for Perth as there are already enough digipeaters. Mine was just adding too much unneeded traffic. It's good to know where it's reaching though.
The antenna is a Comet mobile tri-bander (6/2/70) about 2 metres above the roof of a tin shed. Average terrain is quite low unfortunately, around 20m. Comet claims it to be useful on 6m but in reality it's a 1/4 wave at 52 MHz and requires a decent groundplane. I've supplied some radials in case I get the urge to work 6m from there during my lunch break.
I picked up an FT-1802 for a good price last weekend and that is now the transceiver for the station.
I made an interface cable which connects the D9 socket from the T2 to the 6 pin mike and 3.5mm speaker connectors on the FT-1802 (as well as power, rather than powered through the DC jack. A lot simpler I think) The radio volume was turned down quite low and increased until the RX light on the T2 operated consistently with received stations. Even then the knob is still down very low. I think I'll add a dab of hot glue to stop the volume being bumped.
The radio will be stuck on transmit if the HT jumper is left in on the T2 so remove it. The audio out to the mike is way too high so you must also remove the HI jumper from the T2. Also turn the volume right down in the OTWinCfg application which sets the software volume level. I have it set at around 20%. It's better to have it a bit too low than a bit too high. Anything more will overdrive the radio. That will reduce the chances of other stations decoding you, will cause QRM and possibly spill out beyond the bandwidth allowed. I set the FT-1802 mic gain to 3 as well. I expect the same sort of settings will work with other Yaesu mobiles connected through the speaker and mike connectors. Most other mobiles have a 6 pin packet connector so that would be a much better option (and the settings will differ from mine)
I've left the EQ jumper off the T2 for the moment. It will probably stay off as removing this jumper allows for correcting pre-emphasis built into the radio when using the speaker (which shouldn't be needed when using the packet connector) Some day I hope to hack the radio and put in a connection to the discriminator for RX as well as inject TX audio a bit further down the line, maybe around where CTCSS enters.
The power supply is a 100w SMPSU connected via a diode network to the radio and T2 as well as a 7Ah SLA battery. The battery is always on trickle charge until mains is lost where it then takes over. The digipeater ran for about 13 hours on battery on Friday before shutting down. It was a bit unreliable towards the end. Unfortunately I wasn't actually testing the battery.. I just forgot to turn the mains on when I swapped out the previous PSU I was testing with. D'oh. Off for the whole weekend. Oh well, it's handy to know.
The digipeater has no problems decoding and reaching VK6KSB-3 70 km away.
The antenna is a Comet mobile tri-bander (6/2/70) about 2 metres above the roof of a tin shed. Average terrain is quite low unfortunately, around 20m. Comet claims it to be useful on 6m but in reality it's a 1/4 wave at 52 MHz and requires a decent groundplane. I've supplied some radials in case I get the urge to work 6m from there during my lunch break.
I picked up an FT-1802 for a good price last weekend and that is now the transceiver for the station.
I made an interface cable which connects the D9 socket from the T2 to the 6 pin mike and 3.5mm speaker connectors on the FT-1802 (as well as power, rather than powered through the DC jack. A lot simpler I think) The radio volume was turned down quite low and increased until the RX light on the T2 operated consistently with received stations. Even then the knob is still down very low. I think I'll add a dab of hot glue to stop the volume being bumped.
The radio will be stuck on transmit if the HT jumper is left in on the T2 so remove it. The audio out to the mike is way too high so you must also remove the HI jumper from the T2. Also turn the volume right down in the OTWinCfg application which sets the software volume level. I have it set at around 20%. It's better to have it a bit too low than a bit too high. Anything more will overdrive the radio. That will reduce the chances of other stations decoding you, will cause QRM and possibly spill out beyond the bandwidth allowed. I set the FT-1802 mic gain to 3 as well. I expect the same sort of settings will work with other Yaesu mobiles connected through the speaker and mike connectors. Most other mobiles have a 6 pin packet connector so that would be a much better option (and the settings will differ from mine)
I've left the EQ jumper off the T2 for the moment. It will probably stay off as removing this jumper allows for correcting pre-emphasis built into the radio when using the speaker (which shouldn't be needed when using the packet connector) Some day I hope to hack the radio and put in a connection to the discriminator for RX as well as inject TX audio a bit further down the line, maybe around where CTCSS enters.
The power supply is a 100w SMPSU connected via a diode network to the radio and T2 as well as a 7Ah SLA battery. The battery is always on trickle charge until mains is lost where it then takes over. The digipeater ran for about 13 hours on battery on Friday before shutting down. It was a bit unreliable towards the end. Unfortunately I wasn't actually testing the battery.. I just forgot to turn the mains on when I swapped out the previous PSU I was testing with. D'oh. Off for the whole weekend. Oh well, it's handy to know.
The digipeater has no problems decoding and reaching VK6KSB-3 70 km away.
VK6AHR-3
Hills Amateur Radio Group (HARG) digipeater VK6AHR-3 has been up and running for some time with good results. The FM-92 seems to work well. The loaned KPC-3 TNC works as expected (taking into account the issue with WIDE1-1 on the 8.2 firmware which can't be fixed 100%) Argent finally released some more Tracker2 units. HARG will be installing and setting it up next Saturday as a combined upgrade and APRS workshop for members. The antenna is a j-pole mounted at roof-top. We will be installing a high gain Comet on the HF mast in the near future. We have also started installing a weather station which will integrate with the digipeater.
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