Condensed Consolidated Income Statements - USD ($)	3 Months Ended	6 Months Ended
Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2022	Mar. 31, 2021
Income Statement [Abstract]
Net revenue	$ 30,654,000	$ 21,352,000	$ 50,760,000	$ 40,316,000
Cost of goods sold	24,462,000	15,206,000	40,863,000	31,189,000
Gross profit	6,192,000	6,146,000	9,897,000	9,127,000
Operating expenses:
Product engineering and development	920,000	1,069,000	2,269,000	1,914,000
Selling, general and administrative	3,364,000	3,838,000	6,763,000	7,032,000
Total operating expenses	4,284,000	4,907,000	9,032,000	8,946,000
Operating income	1,908,000	1,239,000	865,000	181,000
Other income (expense), net:
Interest and dividend income, net of fees	296,000	327,000	573,000	1,130,000
Net realized and unrealized gains (losses) on marketable securities, net	(1,488,000)	1,294,000	(1,065,000)	3,488,000
Other	(137,000)		(137,000)
Other income (expense),net	(1,329,000)	1,621,000	(629,000)	4,618,000
Income before income tax expense	579,000	2,860,000	236,000	4,799,000
Income tax expense	140,000	572,000	71,000	960,000
Net income	$ 439,000	$ 2,288,000	$ 165,000	$ 3,839,000
Basic income per common share	$ 0.03	$ 0.16	$ 0.01	$ 0.26
Diluted income per common share	$ 0.03	$ 0.16	$ 0.01	$ 0.26

The aggregate costs related to goods produced and sold and services rendered by an entity during the reporting period. This excludes costs incurred during the reporting period related to financial services rendered and other revenue generating activities.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 924
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 11.L)
-URI http://asc.fasb.org/extlink&oid=6472922&loc=d3e499488-122856

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.2(a),(d))
-URI http://asc.fasb.org/extlink&oid=123367319&loc=SL114868664-224227