Condensed Consolidated Statements of Operations - USD ($)	3 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Income Statement [Abstract]
Net revenue	$ 20,106,000	$ 18,964,000
Cost of goods sold	16,401,000	15,983,000
Gross profit	3,705,000	2,981,000
Operating expenses:
Product engineering and development	1,349,000	845,000
Selling, general and administrative	3,399,000	3,194,000
Total operating expenses	4,748,000	4,039,000
Operating (loss)	(1,043,000)	(1,058,000)
Other income (expense), net:
Interest and dividend income, net of fees	277,000	804,000
Realized and unrealized gains on marketable securities, net	423,000	2,193,000
Other income (expense),net	700,000	2,997,000
Income (loss) before income tax expense (benefit)	(343,000)	1,939,000
Income tax expense (benefit)	(69,000)	388,000
Net income (loss)	$ (274,000)	$ 1,551,000
Basic income (loss) per common share	$ (0.02)	$ 0.11
Diluted income (loss) per common share	$ (0.02)	$ 0.11