Continuing the discussion from LoRa APRS Tracker (Part 4) - #100 by GM4TOE.
Previous discussions:
1 Like
I think that leads to dingle-arm reciprocation and problems with the tremie pipes.
Seriously, I’m hoping we can find a few sites up here in GM land where we can set up some gateways to get some coverage going.
1 Like
Remember to watch again the initial training on this subject as you might have forgotten some details:
3 Likes
The way the presenter keeps a straight face is what impresses me. That and his knowledge of magneto-reluctance and capacitive diractance!
2 Likes
I was tempted to ask where I should put the gateway I have built - but I know I will receive impossible suggestions 
Meanwhile it sits in my loft just in case anybody ventures to the Eastern GM/ES summits!
6 Likes
How’d you set that up? Is it something you can do from the tracker itself, or is it buried in the initial set-up?
1 Like
on BluetoothType
4 Likes
It’s in the initial setup data file. I’m away but from memory it’s the Bluetooth type. It’s enabled for android by default and the value needs to be changed from 1 to 0 or viceversa.
2 Likes
Thanks. More or less by accident my tracker should be set correctly formy phone, but how’d you get the tracker to become discoverable once you have an app looking for the connection?
1 Like
it will always discoverable (either BT classic or BLE)
2 Likes
My Android phone doesn’t see it. What would it be called? 
1 Like
On IoS the standard Bluetooth screen in settings doesn’t show it. However the APRS.fi app just automatically detects it as a BLE modem and connects. No user intervention needed.
1 Like
Or indeed the higher ones. I’ll have my tracker with me on Friday morning for my climb of Ben Avon and Beinn a’Bhuird from the bothy at Faindouran.
I reckon it’s 80km and LOS to you from Ben Avon.
3 Likes
“LORA APRS and some number” ( related to the MAC address of the wifi network)
is your phone only BLE or also has BT classic?
1 Like
In APRSdroid (in Android) I can’t see any clear indication whether it is connected via bluetooth to the tracker or is using a direct connection to the Net. This is what the relevant options page looks like, and it talks about choosing a paired device, but I can’t identify the relevant one (or even if it’s there at all)…
2 Likes
This guy should have been a politician! He’s amazing at saying BS and making it sound real.
1 Like
I turned my tracker on for day 2 of a backpacking trip over the Cairngorms. There are one or two i-gates I thought I might have a small chance of hitting, but I didn’t expect this:
104km or 65 miles
I am using a home made 2m/70cm Signal Stick flexible whip, made with nitinol wire, which is so flexible that there is little load on the trackers SMA connector.
5 Likes
At 3500ft the radio range is about 81.5miles. (1076m / 131 km). But that is in clear space and there will be lots of clutter around you in the mountains to reduce that. The antenna will have been what 5 or 6ft above ground and at that height the radio horizon is about 3 miles. So as long as you could see decreasing height ground in 3 miles then you can get range like this. But we know the Cairngorms consists of large amounts of elevated plateaus where the antenna height above ground is the limit to range. So it is not unreasonable but you were in just the right place.
Ignoring all of that, it’s just cool to think of essentially naff all RF power making the trip. So that’s 2 interesting UHF and up signals yesterday, yours on 439MHz and Jack’s on 2320MHz getting over Ben Venue, Stob a Choin and An Caisteal. Good stuff this propagation lark 
3 Likes
I’m not sure why you were not expecting that really. A glance at the other pings that people get using LoRa APRS in the UK shows that such distances, from elevated locations, are actually quite common. The processing gain of LoRa is significant.
2 Likes
The effect of spreading is non-intuitive though Richard. Well it is at first. We all learn early on that wider bandwidth signals need more power for the same SNR. Then you meet spread signals and find they have quite massive bandwidths but big improvements in SNR over the non-spread case due to the despreading reducing the noise contribution.
5 Likes