Lionel 394 Rotarty Beacon - not rotating

Depending on how quickly you want it to start operating, be prepared to wait a while....it DOESN'T start working as soon as you apply power.  The dimpled bulb on which the beacon hood sits, takes a few minutes to generate enough heat to get the hood to rotate.  The idea is that the heat rises through the vent slots, and starts a turning motion.  If you have any drafts near your layout, expect these to affect the performance.  This is why most operators prefer the 494 beacon, as it works with a solenoid vibrator mechanism.  The nice feature about your 394, is that it is quiet in operation compared to the noisy 494, but it is much more finicky.  You can gently bend open the fins on yours to improve air flow but do each one the same and exercise a lot of patience.  It's actually not a bad operating accessory once you get it tweaked properly.  Probably a lot of folks will disagree.

I've had them on layouts for decades.  Brand new parts, higher voltages, never spun without a tap from my finger.  Love the look whether it spins or not.  

The newer dimple bulbs don't run as hot as the original GE bulbs. You will need 16 volts instead of the rated 14 volt. It will be very bright. The newest repo beacons seem to work better than the older reproductions. (Original beacon tops work the best as they are made of thinner aluminum.)

 Also where you live as some bearing on how they preform, They work best a sea level rather than higher locations, as there is more air to heat at  lower locations.

 And the last thing is they need to be balanced as best possible, and you will sometimes have to give it a little spin to start, but should stay rotating after that.

The vibration from your train(s) running does as much to make the beacon hood rotate as the hot air generated by the dimple bulb, probably more.  

Ron,

Both the 394 & 494 have their good and bad points. The 394 will test your patience as you start to fiddle with it. The steps mentioned above are what you have to follow. Even then you'll still have to help it along. The 494's main fault is the noise caused by the vibratory motor when in use. If you find a used 494, odds are the motor will be shot. You'll question the cost of a new motor against the cost of a new MTH Beacon. Granted the newer pieces are noisy, too. The MTH unit is all plastic which does muffle the vibration. The sound will be less than running train though. I run prewar tinplate. The 494 is quiet in operation when compared to my tinplate trains running..LOL

Also with the 394, you want to make sure the the beacon is balanced and centered on the shaft inside. If the shaft is not plumb, the beacon housing will rub on the tower causing it not to spin.

There's already some good pointers here, especially on vibration. Placing the tower near the track and having it screwed in place will assist in operation of the accessory as the vibration of the trains will help.

I had a plastic Marx version on one of my earlier layouts. What I did, was attach a small DC motor on the underside of the top deck platform. The vibration from the motor made the beacon top spin very nicely.

Another thing I have done on other layouts and am going to do on my new one, is to aim a small DC powered computer cooling fan at the beacon. This also works very well.

Just some alternative ideas that might help you.