Note 1 - Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2022

Notes Tables

Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]

(in thousands)	2022		2021		2020
Weighted average common shares outstanding		48,178		47,409		41,854
Effect of dilutive stock options and restricted stock units		621		1,051		-
		48,799		48,460		41,854

Schedule of Inventory, Current [Table Text Block]

	December 31,		December 25,
	2022		2021
Raw materials and purchased parts	$	106,041	$	92,798
Work in process		36,024		40,732
Finished goods		28,076		27,523
Total inventories	$	170,141	$	161,053

Property, Plant and Equipment [Table Text Block]

	December 31,			December 25,
	2022			2021
Land and land improvements	$	7,066		$	7,703
Buildings and building improvements		31,161			31,711
Machinery and equipment		105,109			95,542
		143,336			134,956
Less accumulated depreciation and amortization		(78,325	)		(70,999	)
Property, plant and equipment, net	$	65,011		$	63,957

Disaggregation of Revenue [Table Text Block]

(in thousands)	2022		2021		2020
Systems-Semiconductor Test & Inspection	$	474,655	$	541,589	$	317,821
Non-systems-Semiconductor Test & Inspection		338,120		318,865		267,419
Systems-PCB Test		-		17,831		33,293
Non-systems-PCB Test		-		8,929		17,474
Net sales	$	812,775	$	887,214	$	636,007