I want to install a Siriusxm radio receiver in an antique car with a 6 volt system. The Sirius receiver comes with a 12 volt power adaptor that has an output of 5 volts/1.5 amps. How do I cleanly drop the 6 volts to 5 volts to power the Sirius receiver?
Will this work, or is there a better solution:
Could someone advise me on how specifically to do this? Any recommendations on what I should buy would be appreciated.
That should work. Be careful touching it, parts may get quite warm.
Your antique car generator will be charging the battery at about 8 volts right after starting the engine. Then when the battery is replenished, the voltage will always be greater than 6 volts, unless the battery is defective. Better double check with a DVM.
Paul
Be careful of polarity: it may well be a vehicle of that age is positive earth.
Many years ago a pal of mine (later acted as Best Man) had a 1964 Ford Cortina Mark1 which was positive earth, but he bought a negative earth radio since by the time he got the car negative earth was the standard. We ended up isolating it from the chassis by mounting it on a block of wood and hard-wiring the radio frame to the car +ve and the radio power to the car -ve.
wilfredmedlin:
Be careful of polarity: it may well be a vehicle of that age is positive earth.Many years ago a pal of mine (later acted as Best Man) had a 1964 Ford Cortina Mark1 which was positive earth, but he bought a negative earth radio since by the time he got the car negative earth was the standard. We ended up isolating it from the chassis by mounting it on a block of wood and hard-wiring the radio frame to the car +ve and the radio power to the car -ve.
How did he go with the aerial mount?
Shield of the Aerial coax is connected to the chassis of the radio, shield at the Aerial end is connected to the chassis of the car! ! ! :o
Tom.. 
TomGeorge:
How did he go with the aerial mount?
Shield of the Aerial coax is connected to the chassis of the radio, shield at the Aerial end is connected to the chassis of the car! ! ! :o
Very good question, and tbh I have no recollection of connecting the aerial. We were students and probably drunk by that stage. I do know it worked, he had the radio in the car for ages after that, so we must have hooked it up somehow. Perhaps it was one of those clip-on jobs on the window glass, but honestly have no idea what we did.
Hmmmmmm.....
Since OP wants to use a voltage converter as a power source they may use some form of negative voltage buck-boost if he has positive earth in the car but negative in radio. Or not?
Thanks for all the replys. Yes, the car is negative ground. Will the step down regulator in the link handle the generator boost and cleanly deliver a constant 5 volts?
You linked to a buck/boost converter, while you only need a buck (stepdown) converter.
Both will work, but the buck (only) might be more efficient.
This one (2.5A) has a lower dropout voltage than it's bigger brother (5A).
Don't expect a switching regulator to be 'clean'.
Leo..
Opie:
Thanks for all the replys. Yes, the car is negative ground. Will the step down regulator in the link handle the generator boost and cleanly deliver a constant 5 volts?
The link data has 30 volts at top value, so even spikes from starter motor should not be a problem. The older cars did not turn off the accessories when starting, like newer cars.
Paul