(please delete this post or move it if this has been done elsewhere, thanks)

Running the DT125 mx 1978 AC / DC system.  Would it make good sense to place a 6v to 5v 3A USB DC 'buck' converter to provide a minimum charge to use a phone as a Navi / route guide
best place to install - headlight bucket ?
best place to wire up - switched DC 6v, what would be the best place?
wire harness - what would be the best solution, a 'bullet type' double to keep things simple / clean / original

would it work well enough and would there be any downside with the draw for the rest of the system.  I believe the bike is a 2 coil system to a rectifier with the battery as a 'dump'

interested to see and find the links to what others have successfully set up, cheers

I wired in a "Buck USB Charging Module DC 6-32V 12V 24V to QC3.0 Fast Charge" item from eBay to my '76 DT100 battery and blew it up. Identified my regulator was bad.
Wired in a new one and so far working well 

Astro ! That was a rough start. I dont want it to run straight off the batt but rather be on a 'switched' source as I believe they can still drain even when unplugged. Good to hear others are trying to go this route.

Important to note that the power taken directly from a bikes electrical system is not "clean".  Not advisable for running sensitive electronics without some means of smoothing it out first.

I have a feeling that Peter (Pete RT1) rigged up something when he and Bernard did their TET run last year - hopefully he'll see this thread and post about it.

Good memory Alan.
Yes, I stepped up to 12v and added a usb port as it was more versatile.
I decided it was safe to charge my powerbank with it, then in turn charge my phone from that since the phone cost is a lot more than a £20 powerbank.
Took it off The Greenie soon after last year's adventure, might need to dig it back out for this year.
Had a look back at the video of the trip, we certainly had some fun.
Here's the post  12v Step-up Transformer - Vintage Enduro Discussions

I understand that 6v to 5v is optimistic given voltage drop. I wonder how much 'not clean' power a little 'buck' converter can handle. I'll have to muster up some energy to move ahead with this. I put a simple phone holder on the bars and can now check my phone map from time to time but the battery does discharge fairly quickly in map mode with the screen on.