Note 5 - Property and Equipment - Property and Equipment (Details) - USD ($)	Dec. 31, 2023	Dec. 31, 2022
Buildings	$ 493,000	$ 493,000
Machinery and equipment	15,461,000	14,948,000
Office furniture and equipment	2,541,000	2,393,000
Leasehold improvements	658,000	606,000
Software	3,000	3,000
Property, Plant and Equipment, Gross	19,156,000	18,443,000
Less accumulated depreciation and amortization	(13,569,000)	(12,701,000)
Total net property and equipment	$ 5,587,000	$ 5,742,000