Note 5 - Inventories (Details Textual) - USD ($) |
3 Months Ended | 12 Months Ended | |
|---|---|---|---|
Dec. 31, 2019 |
Dec. 31, 2018 |
Sep. 30, 2019 |
|
| Inventory Write-down | $ 28,000 | ||
| Inventory Valuation Reserves, Ending Balance | 1,275,000 | $ 1,275,000 | |
| Telco [Member] | |||
| Inventory Write-down | 0 | 0 | |
| Inventory Valuation Reserves, Ending Balance | $ 1,300,000 | $ 1,300,000 | |