Note 4 - Discontinued Operations - Sale of Cable TV Segment (Details) - USD ($)		1 Months Ended	12 Months Ended
	May 29, 2019	Mar. 31, 2019	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2017	Jun. 30, 2019	Nov. 29, 2018
Current assets of discontinued operations				$ 16,925,526
Non-current assets of discontinued operations				1,524,972
Current liabilities of discontinued operations				2,392,780
Income tax provision			8,000	119,000	$ 684,000
Discontinued operations, net of tax			(1,267,344)	(1,536,159)	2,357,629
Cable TV Business Segment [Member]
Net purchase price			14,200,000
Pretax loss on sale of net assets of Cable TV segment			1,500,000
Cable TV Business Segment [Member] | Discontinued Operations, Disposed of by Sale [Member]
Net purchase price			14,203,199
Net assets sold			15,695,574
Pretax loss on sale of net assets of Cable TV segment			(1,492,375)
Cash received from real estate facility sales			7,075,000
Cash received from sale of Cable TV segment			753,199
Promissory note from sale of Cable TV segment			6,375,000
Total net sales			13,743,339		22,806,175
Cost of sales			10,096,553		15,067,820
Operating, selling, general and administrative expenses			3,411,869		4,676,398
Other expenses			1,886		20,328
Income (loss) from discontinued operations			233,031		3,041,629
Income tax provision			8,000		684,000
Discontinued operations, net of tax			(1,267,344)		$ 2,357,629
Cable TV Business Segment [Member] | Discontinued Operations, Held-for-sale [Member]
Accounts receivable				1,821,870
Pretax loss on sale of net assets of Cable TV segment
Inventories				11,425,551
Prepaid expenses				11,352
Assets held for sale				3,666,753
Current assets of discontinued operations				16,925,526
Land and building				2,208,676
Machinery and equipment				2,800,835
Leasehold improvements				9,633
Less accumulated depreciation				(3,502,712)
Net property and equipment				1,516,432
Deposits and other assets				8,540
Non-current assets of discontinued operations				1,524,972
Accounts payable				1,356,800
Accrued expenses				438,074
Notes payable – current portion				597,906
Current liabilities of discontinued operations				2,392,780
Total net sales				19,940,705
Cost of sales				16,134,944
Operating, selling, general and administrative expenses				5,201,214
Other expenses				21,706
Income (loss) from discontinued operations				(1,417,159)
Income tax provision				119,000
Discontinued operations, net of tax				$ (1,536,159)
Cable TV Business Segment [Member] | Leveling 8 [Member]
Contract price						$ 10,300,000
Less: Real estate sales		$ 2,100,000
Less: Working capital adjustment			700,000			1,100,000
Cash received from real estate facility sales						3,900,000
Promissory note from sale of Cable TV segment						$ 6,400,000
Cable TV Business Segment [Member] | Leveling 8 [Member] | Discontinued Operations, Disposed of by Sale [Member]
Contract price	$ 10,314,141
Less: Real estate sales	2,075,000
Less: Working capital adjustment	1,110,942
Net purchase price	7,128,199
Accounts receivable	2,038,305
Inventories	10,258,487
Prepaids and other assets	73,073
Property and equipment, net	335,980
	12,705,845
Accounts payable	1,306,294
Accrued expenses	466,759
	1,773,053
Net assets sold	10,932,792		10,932,792
Pretax loss on sale of net assets of Cable TV segment	$ (3,804,593)
Cable TV Business Segment [Member] | David Chymiak [Member]
Net purchase price							$ 5,000,000
Cable TV Business Segment [Member] | David Chymiak [Member] | Discontinued Operations, Disposed of by Sale [Member]
Net purchase price		7,075,000
Net assets sold		4,762,782	$ 4,762,782
Pretax loss on sale of net assets of Cable TV segment		$ 2,312,218