Parts
Car: Toyota Pro Ace City, which is same as Citroen Berlingo, Opel Combo, and Peugeot Partner
Antenna: Sirio - SKA 901 C | K-PO
Magnetic mount: Sirio - SKA 900 1/4 MAG | K-PO
Node: Station G2 from Meshtastic Mesh Device Station G2 – B&Q Consulting Shop
Adaptor: FME male to SMA male https://amzn.eu/d/bm331pJ
Power bank: Jackery Explorer 240 (note this switches off after 10 hours automatically, see here for alternatives Station G2 | Unit Engineering)
Power bank USB PD adaptor: https://amzn.eu/d/7yupZTB (is a bit loose, there may be better ones) - the node needs USB PD (not normal USB)
(One can run the node from 12V as it has a 12 V input. Or one can use a USB PD adaptor in the 12V socket of the car. I find a power bank easier to handle in terms of wiring being less messy.)
USB power cable that supports high power e.g. https://amzn.eu/d/7yupZTB or 3m like this one https://amzn.eu/d/7yupZTB . Not all USB cables will deliver enough power - if the power is sufficient, all three LED lights of different colours must be on, if not, only red light is seen.
Duct tape: (this can leave a sticky residue, so probably there are better ways of doing this…)
Feeding cable into car from roof
The SKA-901-C antenna screws into the magnetic base of the SKA-900-1-4-mag. (I could not order the antenna I wanted with the base). The antenna has a very sturdy and long cable but one has to avoid running it through any gap that closes tight below about 5 mm. For a modern car this is a tough ask - most doors close much tighter than that so the cable is too fat to pass past a door. In this case the only place with a sufficient gap was at the hinges of the upward opening boot. I placed the antenna near this hinge otherwise there would an issue with too much cable on the roof and the wind having more to work on. Therefore the height and angle of the antenna might not be perfect. The cable had at some point to pass though a gap in the boot - and the rubber seals then simply press against it. I passed it at a point where, if the rubber seal were somehow dented and no longer waterproof, the location was low down at the base of the boot door where water was not going to run in from above: so the very long antenna cable allowed for this option. Then the cable was run up the car boot on the side and passed into the roof compartment where there was a big enough gap to squeeze through.
The node lives in a roof compartment
Power details
Running the node from a battery was nicer because running the engine to run the node was not an option when the node has to be in a given location some time to detect any other nodes. The power details are as per the the previous arrangement described here Car node under sunroof . Update 20-9-24 : Using this antenna with the Jackery 240 battery pack described in the previous link, results is the battery pack NOT switching off every 10 hours. The power draw is large enough that the battery does not switch off the power output every 10 hours - it keeps it alive. The battery can still, however, power the node for about a week. Serendipity perhaps. Not clear if this is reproducible using the same components in other builds, or just a one-off fluke or a sign that there is something wrong electrically…
Results
Obviously the cable from the antenna to the node is very long indeed and may say this is sub-optimal. So will see if this compares well to the antenna the node came with. But using the antenna that came with the Station G2 and placing the device immediately under the sun-roof (see Car node under sunroof) I got superb results up to 45 km (Car node under sunroof - #7 by adingbatponder). So using an external antenna is an interesting comparison. I will see if the antenna can stay on at all times and speeds…
1.9.24 Testing shows the antenna receives well. Would need testing from known locations, where the other configuration with antenna under sunroof worked, to see if better or worse.
2.9.24 The antenna works well to pick up many nodes. The following connection was made (car top right), which I am not sure I managed with the internal antenna.
and the location is according to https://www.heywhatsthat.com/ is really not a good one, as shown below:
So I consider this test alone to show it is an adequate antenna and the long cable to the node seems not to cause it to fail to work nicely.
The following was also achieved, but to a new antenna at the receiving end (bottom left) (antenna (b) in this post Using multiple antennae and nodes in the same location )
The car node shown achieved a 30 km traceroute:
in which the first node was immediately next to the car node “Dong”
but that was during a period of thunderstorms.
The car node with this external antenna worked well in town also - achieving direct messaged with tick to several of the antennae at home (Using multiple antennae and nodes in the same location) despite being in a very built-up area.
This is a traceroute with a node 100 km away:
so I consider this external antenna to be as good as necessary even with the 3 m coaxial cable coming from it when used by a Station G2 (which has neat electronics, so this might not apply when used with other nodes, which probably should first avoid such a long cable from antenna to the node).
