Annual report pursuant to Section 13 and 15(d)

Note 7 - Concentrations (Details Textual)

v3.23.3
Note 7 - Concentrations (Details Textual)
12 Months Ended
Sep. 30, 2023
USD ($)
Sep. 30, 2022
USD ($)
Sep. 30, 2021
Sep. 30, 2020
Property, Plant and Equipment, Net $ 21,527,000 $ 18,229,000    
MEXICO        
Property, Plant and Equipment, Net 7,003,000 4,213,000    
Oulu, Finland [Member] | Nestor Cables [Member]        
Property, Plant and Equipment, Net 6,703,000 6,916,000    
Keila, Estonia [Member] | Nestor Cables [Member]        
Property, Plant and Equipment, Net $ 660,000 $ 280,000    
Revenue Benchmark [Member] | Customer Concentration Risk [Member]        
Number of Major Customers 1 1 2 2
Revenue Benchmark [Member] | Customer Concentration Risk [Member] | One Customer [Member]        
Concentration Risk, Percentage 16.00% 14.00%    
Revenue Benchmark [Member] | Customer Concentration Risk [Member] | Two Customers [Member]        
Concentration Risk, Percentage     28.00%  
Accounts Receivable [Member] | Customer Concentration Risk [Member]        
Number of Major Customers 3 1    
Accounts Receivable [Member] | Customer Concentration Risk [Member] | One Customer [Member]        
Concentration Risk, Percentage   20.00%    
Accounts Receivable [Member] | Customer Concentration Risk [Member] | Customer One [Member]        
Concentration Risk, Percentage 16.00%      
Accounts Receivable [Member] | Customer Concentration Risk [Member] | Customer Two [Member]        
Concentration Risk, Percentage 13.00%      
Accounts Receivable [Member] | Customer Concentration Risk [Member] | Customer Three [Member]        
Concentration Risk, Percentage 11.00%