Here we go again. John, Dale & Dale, please check this for me. I will iterate the sketch until it's right so it can be copied by anyone. This is the conversion for the later model post war floodlight tower that has Christmas light type bulbs. The conversion of the earlier 195 tower will follow. I choose to go with this one first because John will be converting one of these towers.
This sketch is up to date. It's a 279 kb JPEG.
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Looks good to me. 
Is there a polarty to the resisiors?
Is there a polarty to the resisiors?
No
Dale H
Thanks
What are the specs for the resistors?
What are the specs for the resistors?
Quarter watt carbon film resistors will do fine there. As stated in the diagram, they're 300 ohms, though if you use something like 330 ohms, it'll work fine, and they're easier to find.
Resistor value (both wattage and ohm value) depends on the input voltage, the specs of the LEDs and they way they are wired. In towers I use 100 ma LEDs,they are very bright as a prototype floodlight tower would be. But this is only practical using series wiring since my input is 12 volts. If the LEDs are series wired with a rectifier there is much less waste of power used by the resistor. On 20 ma ones this is not usually a factor to consider but is with 100ma ones.
The back to back design here seems to work good.
Dale H
Well, you're right Dale, if they were 100ma LED's, you might need a heftier resistor. However, you'd probably not be using a 300 ohm resistor for 100ma LED's. 
I just finished the conversion and it works really well. I used 5mm LEDs and 300 ohm resistors. Those tiny resistors fit snugly on the back of the light assembly, and they can stand vertically in the route of the original leads.
The only tweaking necessary was to get the LEDs to contact the buses inside the light head. I am very pleased with the results. Now onto the more difficult 195 conversion. More to follow.
Here's a tip to keep the chrome reflectors on snug. Mine were warped from the heat radiated from the incandescent bulb. Put some shrink sleeve on the sockets to make any loose reflector fit better.
This whole project took me about an hour to accomplish.
Is your diagram in the thread up to date?
Yes, now it is. I tested the tower conversion up to 14Vac and it works well with more illumination than the incandescent bulbs gave, no heat and no noticeable flicker.
Great, we should have an archive for stuff like that drawing, very helpful.
Thanks for taking the extra time to share, Bobby.
Susan,
I enjoy giving something back for all of the good help I get from this forum.
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