Note 8 - Concentrations of Credit Risk	6 Months Ended
Apr. 30, 2021
Notes to Financial Statements
Concentration Risk Disclosure [Text Block]	Note 8 – Concentrations of credit risk Financial instruments that potentially subject us to concentrations of credit risk consist primarily of cash and cash equivalents and accounts receivable. We maintain our cash and cash equivalents with high-credit quality financial institutions. At April 30, 2021, we had cash and cash equivalent balances in excess of federally insured limits in the amount of approximately $13.4 million. Two customers, both distributors, accounted for approximately 12% and 11% of net sales for the three months ended April 30, 2021, and 14% and 11%, respectively, of net sales for the six months ended April 30, 2021. These distributors had accounts receivable balances that accounted for 14% and 13%, respectively, of the total net accounts receivable balance at April 30, 2021. The two distributors also accounted for 17% and 11% of net sales for the three months ended April 30, 2020, and 14% and 11%, respectively, of net sales for the six months ended April 30, 2020. In the same six-month period, another customer, a wireless carrier, accounted for 11% of net sales. The two distributors had accounts receivable balances that accounted for 19% and 14%, respectively, of the total net accounts receivable balance at April 30, 2020. Although these customers have been on-going major customers of the Company, the written agreements with these customers do not have any minimum purchase obligations and they could stop buying our products at any time and for any reason. A reduction, delay or cancellation of orders from these customers or the loss of these customers could significantly reduce our future revenues and profits.

Note 8 - Concentrations of Credit Risk

6 Months Ended

Apr. 30, 2021

Concentration Risk Disclosure [Text Block]

Note 8 – Concentrations of credit risk

Financial instruments that potentially subject us to concentrations of credit risk consist primarily of cash and cash equivalents and accounts receivable. We maintain our cash and cash equivalents with high-credit quality financial institutions. At April 30, 2021, we had cash and cash equivalent balances in excess of federally insured limits in the amount of approximately $13.4 million.

Two customers, both distributors, accounted for approximately 12% and 11% of net sales for the three months ended April 30, 2021, and 14% and 11%, respectively, of net sales for the six months ended April 30, 2021. These distributors had accounts receivable balances that accounted for 14% and 13%, respectively, of the total net accounts receivable balance at April 30, 2021. The two distributors also accounted for 17% and 11% of net sales for the three months ended April 30, 2020, and 14% and 11%, respectively, of net sales for the six months ended April 30, 2020. In the same six-month period, another customer, a wireless carrier, accounted for 11% of net sales. The two distributors had accounts receivable balances that accounted for 19% and 14%, respectively, of the total net accounts receivable balance at April 30, 2020. Although these customers have been on-going major customers of the Company, the written agreements with these customers do not have any minimum purchase obligations and they could stop buying our products at any time and for any reason. A reduction, delay or cancellation of orders from these customers or the loss of these customers could significantly reduce our future revenues and profits.