CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2023	Dec. 31, 2022
Income Statement [Abstract]
Net sales	$ 12,588	$ 11,282	$ 24,526	$ 22,369
Cost of sales	9,786	8,659	18,066	16,791
Gross profit	2,802	2,623	6,460	5,578
Operating expenses:
Selling expenses	37	68	63	122
General and administrative expenses	1,200	951	2,195	1,975
Research and development costs	788	467	1,593	1,395
Total operating expenses	2,025	1,486	3,851	3,492
Operating income	777	1,137	2,609	2,086
Interest expense	(139)	(128)	(271)	(258)
Unrealized gain (loss) on marketable equity investments	(40)	2,740	(2,593)	3,165
Interest and other income	22	7	46	225
Gain on sale of investments				7
Income (loss) before income taxes	620	3,756	(209)	5,225
Income tax benefit (expense)	(120)	(1,004)	94	(1,270)
Net income (loss)	$ 500	$ 2,752	$ (115)	$ 3,955
Basic net income (loss) per share:
Net income (loss)	$ 0.14	$ 0.77	$ (0.03)	$ 1.10
Diluted net income (loss) per share:
Net income (loss)	$ 0.14	$ 0.75	$ (0.03)	$ 1.08
Weighted-average common shares outstanding:
Basic	3,547	3,574	3,547	3,595
Diluted	3,612	3,652	3,547	3,672
Common shares outstanding	3,541	3,554	3,541	3,554