Note 5 - Revenue - Disaggregation of Revenue (Details) - USD ($)	3 Months Ended		9 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Total Net Sales	$ 25,970,045	$ 21,892,244	$ 65,756,545	$ 61,065,759
Percent of net sales	100.00%	100.00%	100.00%	100.00%
Broadband Service Providers [Member]
Percent of net sales	97.00%	97.00%	96.00%	95.00%
Build-to-print Customers [Member]
Percent of net sales	3.00%	3.00%	4.00%	5.00%
UNITED STATES
Total Net Sales	$ 25,090,614	$ 20,243,754	$ 62,765,455	$ 55,861,025
Non-US [Member]
Total Net Sales	$ 879,431	$ 1,648,490	$ 2,991,090	$ 5,204,734