This is a simple QRP transmitter modeled after a schematic from and OLD ARRL handbook. Maybe its the glow of the tubes or the heat they produce.
I want to add a small compressor to my truck to keep the rear level. It has air shocks but no automatic control.
If I can find a decent priced string pot I can make it fully automatic. for now I need to select a compressor.
I have a few factory ones and a bunch of aftermarket tire pumps. You cant believe the hyped up ratings so I made a simple arduino test rig to sample the pressure every 100 milliseconds and decided to test every one I can get my hands on….
heres the test setup using a battery, pressure sensor, safety cutoff switch and a few other parts…..
and heres the lot of compressors I grabbed from the junk bin and all the cars outside.
There’s this monster from a Caddy Deville. It even has the solenoid to drop the suspension attached.
A bare frame from a factory air suspension: Not the fastest but its the one I’m using for my suspension. Its beefy and runs at a lower speed than the others so it will be quieter… Plus it has two 1/8 npt ports on the head that will make plumbing a breeze.. I probably should print up a belt guard for it.,,,,
a very old compressor from the 80’s
what I thought was a cheapie model but turned out better than expected so I gave it a brand new gauge and 3D printed a new cap for the head…..
A left over from a project. Its a cheap aftermarket car compressor with a 3D printed base…
Real cheapo flea market garbage. wouldn’t hit 200psi if I kinked its hose with vice grips…….
A nice $5 flea market one thats going back in my wagon…
A real surprise is the harbor freight model. It was #2
by far the best and most expensive one I have. Its made by slime. Its big ugly and fast and I keep it in my truck
and the results:
the rest were about even.