Pictured above are a pair of NOS Ford A-12300 ignition condensers. These have the Ford script and the zinc can.
Pictured below is a 1928 letter from Ford in reply to a reporter's question about the rating of the ignition condenser. According to the Ford letter, the capacitance is 0.3 microfarads.
Also noted in the letter is the fact that the ignition coil has 250 turns of #20 enameled wire in 4 layers in the Primary winding, and that the Secondary winding has 16,000 turns of #38 enameled wire.
A word about Condensers:
It is generally unreliable and not recommended to use NOS old condensers due to the technology used to make them. Many of them are subject to failure due to perforation of the internal wax paper type insulator which separates the foil layers.
This failure risk is compounded by the physical location of the condenser on a Model A. It is placed inside the cast iron distributor casting, just above the cylinder head, and close to the exhaust manifold.
The Model A distributor is a high temperature environment with little air circulation or cooling. Virtually all other automotive condensers are placed up high away from engine heat, and inside more thermally conductive aluminum distributors.
To minimize the risk of condenser failure, it is generally held that the modern "burnout-proof" condensers produced specifically by A&L Parts Specialties are the best performing and most reliable. The A&L condenser has a modern polyester film internal insulator and is specifically designed to withstand the high heat conditions found in the Model A application.
Contact:
A&L Parts Specialties
Box 301
Canton, Connecticut 06019
(860) 693-2620
No web site