It’s official. I’ve got the Meshtastic bug. It’s not like I need any more hobbies but the mixture of amateur radio and tech is continuing its grasp on my attention. It’s great fun and that drive to push for contacts has had me out walking more than ever before.
Here’s a little recap on what has been going on at Retro32 Base (R32B)
Stealth Solar off-grid budget node
Using a low-power Rak Wisblock combined with a “working” Paradar antenna and a garden LED light, I have constructed my first off-grid node. Using a cheap solar LED light from Amazon (https://amzn.to/4cuotXJ), I combined the crappy panel, the supplied 18650 cell and the highly efficient Rak into a work of art.
https://store.rakwireless.com/products/wisblock-meshtastic-starter-kit
Despite the questionable solar “panel” and battery the node has managed to stay charged (up to its max of 70%) for nearly a week and remained watertight throughout testing while mounted to my shed in a South facing position. The Wisblock is the perfect fit for this job as it sips less than a 5th of the power demanded by the Heltek V3, has solar charging and a battery connector on board. No messing about and a simple project for anyone wanting to have a play.
It’s currently in parts waiting for it’s final build, I’ll be throwing a couple of silica bags in there to help should any moisture creep in.
The enclosure was “sealed” with hot glue and taped up to hide what was inside (a great way to hide the flashing LED).
The plan is to have this stuck up a tree in my favourite Yagi pointing spot just outside of Stamford which should see my base node jumping into the Peterborough mesh. I just need to throw my ladders in the van and head over this weekend.
Height is might!
I’ve also been taking the opportunity to try out some more long-range tests at “altitude” with the Paradar (more on that below) antennas. The Yagi performed great, especially when I managed to put it on a 6m pole, leaving my regular contacts nearly 50 km able to two-way message with ease. The office tests weren’t very successful but there was a reason for that.
These tests go to show how much difference height can make. We even had a visit from a flying node a couple of weekends ago that saw contacts in Bedford and beyond. This has sparked another idea for my own “airborne” idea.
Antenna testing
As discussed above, my long-range testing has been very hit or miss, Frustratingly, this led me to believe there was an issue with my Paradar whip antenna. After hearing from others in the Mesh community with similar issues with Paradar, I decided to acquire a Spectrum Analyser and see what was going on. Here are my results.
Yep, it’s dead. You can clearly see what’s up here. It’s DEAD. Or f****d if you like.
With the whip snapped at the base the antenna core pulled back through. The same as this…
and now this…
Despite the CA – the antenna was not not even tuned to 868Mhz… So it’s being returned. We’re not the first ones to experience tuning issues with the Paradar whips.
There fore this was a completely fruitless task
Luckily the Paradar Yagi has been an absolute beast, its suggested range of 815 to 896Mhz seems about right. I picked this one up from Amazon – https://amzn.to/3vkPFYm – Not to s**t on Paradar too much, this Yagi has been consistently great, its just a good thing I have the van or this would not be possible as a mobile node.
The cheap Amazon Meshtastic antennas are crap. Don’t waste your money. Things are not always what they seem on Amazon – these will be returned too.
This spectrum analyzer, however, is an essential bit of kit. So much so that I’ll be attempting my own DIY antenna in the next few weeks – https://amzn.to/4cruF2R
With the countless hours I’ve wasted driving around with that broken Paradar whip, I wish I picked one up earlier. For anyone interested, it took me a while to work out how to set the analyser up. If you’ve like to to put together a quick guide then let me know.
Links
If you’d like to buy things that I’ve covered above then see the links below
- Paradar Antennas (Hopefully yours will work) – https://amzn.to/3VA6Tvn
- Nanovan Spectrum Analyser – https://amzn.to/3VAITbr
- Velux Pole – Great for getting that height and collapsable – https://amzn.to/3VDVJFV
- Solar LED Garden lights – https://amzn.to/4cuotXJ
- Meshtastic UK – East Facebook page – https://www.facebook.com/groups/meshtasticukeast
- Meshtastic UK Facebook page – https://www.facebook.com/groups/625434626178266
- Also, check out my first meshtastic article below
Buy Heltek V3 Meshtastic kits
We have a small number of Heltek V3 LoRa boards available from our store. Note that we’d recommend that you update the antenna ASAP. Links to Paradar antennas is above.
They come pre-flashed and ready to go. They are selling out quickly so keep checking back for stock updates.
Let’s hear from you
Let’s hear your experiences of Meshtastic in the comments below. Have you had any issues with Paradar? Have you got any suggestions for new antennas to try out? Let’s hear from you.
I found the Paradar whip well tuned to 869 till I stuffed it in my rucksack and snapped it. My problems started when I attached it to a heltec mounted in a sandwich box charged with long USB cable and tie wrapped it high up on a tower. I checked my local rf signals all around – 100 rssi. About an hour later a squally rain shower came by and all rssi values dropped to -128 obviously water or static? Reinstalled another heltec with home brew sleeve dipole sigs back as before no sign of water issue. This lasted a week till after some rain showers rssi all back to -128 bought a Mcgill 6dB with a 3rd heltec properly mounted bolted to the tower with clamps. Signals back as before till last Saturday a short hail shower and you’ve guessed by now looked at the heltec rf o/p circuit and the problem seems clear there is NO dc bleed resistor to earth on the heltec board just a tiny capacitor into a pi matching network. When using any of the simple vertical whips any static rain shower charges up the fibreglass radome and whip till the tiny coupling capacitor breaks down killing the rf c/o switch rendering the heltec dead. I have put up a 4th heltec with a high value resistor across the ipx connector still with the Mcgill and have crossed fingers awaiting showers.
How did you manage to mount a resistor across the IPX connector? Way too small for me to find access