Why not use the 47Ghz band on ham radio? Amateur radio operators have been able to communicate via long distances using these frequencies.

@jay Cause he wants to talk to someone and cook a hot dog at the same time.

The chart posted by @John Smith is most interesting for its F > 275MHz values – visible light!

@jay;Anymore fewer and fewer hams construct rigs. Homebrew is the only option for those hams who want to experiment from away from the crowd.

Respectfully ask why a ham would want to do this, is like asking why anyone would want to do any of the projects posted on hackaday :)

UHF circuitry can be tricky enough until one gains some experience working with it, I’m sure the same is true of this portion of the microwave bands. But this article shows why few experienced with UHF homebrew may never homebrew at 47 GHz. Not as dedicated as others to the craft, to each our own thing.

Nice build Tony!

Next time you want to make the inner platter perfectly round, one answer is to cut it to a slightly oversize diameter on your lathe (perhaps +.010 if you can manage the accuracy,) then mount it back on your hard drive spindle. Mount a rotary grinder (Dremel) on the chuck so the axis of the grinder is parallel to the axis of the hard disk drive motor, and the grinding wheel is centered on the platter. Rigidly fix the height of the chop-saw vertical travel so the platter can meet the middle of the grinding wheel. Using the hard drive motor to spin the platter at full speed, bring it down to the final diameter by moving the chuck very, very slowly into the rotating platter. Sparks should be no brighter than barely visible during this operation, or you could distort the platter with heat or cause some problem.

I would consider using a dribble of water or a mister as a coolant during this operation, but if you’re going slow enough it shouldn’t be necessary. Keep in mind that as the aluminium platter gets hotter, it expands. A hot platter will give a falsely large diameter reading.

The trick is to use the mounting position on the axle as the axle for truing the wheel. By definition, it won’t be out of round, as long as you finish the cut extremely carefully.

You could also consider shrink fitting the blade to the trued platter. Leave the platter over the size of the blade’s inside diameter by .003 or so. Make sure the platter is just slightly too big to fit in the blade’s hole. Place the platter in the freezer for an hour, laying flat. Lay the frozen platter on a cool and very flat work surface. Lay the room-temperature saw blade on the platter — it should fit easily. As the platter heats, it will expand to fill the blade’s inner diameter, leaving a very snug fit.

@jwt

you could die from driving … you could die from eating … you could die from taking a shower … you could die doing 90% of the stuff you do every single day
but will you? …. well … yah most likely …. eventually … i dont think a spinning hard drive miter saw will raze or lower that chance any

@Imroy

Its worse then that. Every component naturally has a capacitance and inductance associated with it. That includes the traces, the component legs, the ground plane, the leads on components, etc. As the frequency increases, the more these values affect the circuit since their reactance is larger. At these frequencies a right angle trace or a thick trace over a ground plane might act as a larger capacitor then any he would place on the board itself.

nice, i’d like to figure out how to make this water resistant so i could spray water on the blade so i could carve in to glass. i’m a glassblower and this would be cool to have in the shop for small intricate cuts