Coil I have has an open and damaged secondary (3.4 ohms winding).
Can somebody provide me some tech information about this winding:
- wire size
- number of turns
- widing direction (clockwise?)
- any particular hint?
- drawing?
If it's the outside winding- the tickler winding, it's fairly easy to rewind. It is NOT a critical winding. I use #34 wire since I have a spool of it; any wire #34 to 38 will work; as I recall it takes about 17 turns and they can be wound without removing the coil if you are careful. The exact number of turns is NOT critical. Several people here will be upset with this advice but I have done this perhaps 5 times.
The wire usually opens on the outside where it makes a 90 degree bend to the solder joint. (The original coil winding machine created a stress at this point which opens over time). It is possible to carefully unwind one turn (or two) to find the open and reconnect it.
If you rewind or find your open winding, you will need to carefully scrape the insulation from the wire with a small, sharp knife blade before soldering.
Thanks Pate for taking your time providing me an answer.
One last question: what is the direction of winding looking at the base of the coil - clockwise or counterclockwise?
You will find the correct winding direction when you unwind the old coil. Also, when you rewind the coil, leave your leads long enough to reverse them if necessary. Phase IS important here but can be simply corrected by swapping the leads.
Hi Pete, I will do that. Thanks for your answer.
Hello Pete, I redid the winding using a #36 wire, in a counterclockwise direction, coated it with a proper wax and the radio is playing well cause I had replaced all paper caps, including the ones in the cap bank, refurbished the electrolytic cap and replaced all the "dog bones" out of spec resistors.
Thanks again for your help. Valentino (from Brazil)