Consolidated Statements of Cash Flows - USD ($)	3 Months Ended	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2021	Dec. 31, 2020
Cash Flows from Operating Activities:
Net income (loss)	$ (1,297,000)	$ (1,297,000)	$ 79,000
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	536,000	536,000	529,000
Stock-based compensation	469,000		392,000
Gain on forgiveness of debt	0		(896,000)
Amortization of discount on note payable	61,000		91,000
Non-cash interest	80,000		121,000
Changes in operating assets and liabilities:
Contracts and other receivables	(931,000)		2,950,000
Costs and estimated earnings in excess of billings on uncompleted contracts	233,000		(625,000)
Inventories, net	(650,000)		1,156,000
Prepaid expenses and other current assets	(927,000)		(126,000)
Right-of-use assets	690,000		605,000
Accounts payable and accrued expenses	(6,358,000)		4,523,000
Deferred revenues	(1,604,000)		1,843,000
Operating lease liabilities	(754,000)		(645,000)
Other liabilities	0		0
Net cash provided by (used in) operating activities	(10,452,000)		9,997,000
Cash Flows from Investing Activities:
Capital expenditures	(64,000)		(396,000)
Net cash provided by (used in) investing activities	(64,000)		(396,000)
Cash Flows from Financing Activities:
Repurchase of treasury stock	(197,000)		(174,000)
Proceeds from bank promissory note	0		890,000
Repayment of long-term borrowings	(352,000)		0
Proceeds from exercise of warrants	0		15,000
Proceeds from issuance of stock	45,000		2,000
Net cash provided by (used in) financing activities	(504,000)		733,000
Net increase (decrease) in cash	(11,020,000)		10,334,000
Cash, beginning of period	19,012,000	19,012,000	8,678,000
Cash, end of period	7,992,000	7,992,000	19,012,000
Supplemental disclosure of cash flow information:
Cash paid for interest	348,000		154,000
Cash paid for taxes	51,000		62,000
Non-cash financing activities:
Forgiveness of bank promissory note (see Note 3)	0		896,000
Operating lease additions	$ 5,364	$ 5,364,000	$ 0