Note 18 - Business Segments - Business Segment Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Jun. 30, 2024	Jun. 30, 2023
Revenues	$ 42,312	$ 43,250
Operating Income (Loss)	1,093	2,228
Depreciation and amortization	42,540	42,186
Depr. and Amort.	4,341	5,088
Capital Expenditures	542	4,498
Segment Reporting, Reconciling Item, Corporate Nonsegment [Member]
Revenues	0	0
Operating Income (Loss)	(230)	(80)
Depreciation and amortization	383	500
Depr. and Amort.	27	0
Capital Expenditures	211	26
Manufacturing [Member]
Revenues	16,057	13,827
Manufacturing [Member] | Operating Segments [Member]
Revenues	16,057	13,827
Operating Income (Loss)	616	(58)
Depreciation and amortization	17,978	13,864
Depr. and Amort.	393	481
Capital Expenditures	58	143
Testing Services [Member]
Revenues	17,933	23,130
Testing Services [Member] | Operating Segments [Member]
Revenues	17,933	23,130
Operating Income (Loss)	(322)	1,648
Depreciation and amortization	20,193	24,559
Depr. and Amort.	3,849	4,532
Capital Expenditures	235	4,329
Distribution [Member]
Revenues	8,297	6,270
Distribution [Member] | Operating Segments [Member]
Revenues	8,297	6,270
Operating Income (Loss)	1,129	816
Depreciation and amortization	1,609	1,275
Depr. and Amort.		0
Capital Expenditures	38	0
Real Estate Segment [Member]
Revenues	25	23
Real Estate Segment [Member] | Operating Segments [Member]
Revenues	25	23
Operating Income (Loss)	(100)	(98)
Depreciation and amortization	2,377	1,988
Depr. and Amort.	72	75
Capital Expenditures	$ 0	$ 0