Repair of CS800 External Speaker Problem

Connect Systems is going to offer you three options for fixing the external speaker problem:

1. You can send the radio to us and we will pay for shipping both ways. We will get you a FedEx or USPS call tag to send it back to us. WE WILL NOT REIMBURSE YOU IF YOU SEND IT YOURSELF.

2. We will send you a P4KE12CA diode and have you install it yourself. To install the diode you need to take off the top cover and install the diode on top of the Speaker Jack. This is a relatively easy job because it is NOT surface mount. The diodes are a D041 case with leads.

3. You do nothing.

4. At this time this is only a possibility. We will supply a diode on an external device that will plug into the radio and you will then plug your speaker into that external device.

The problem was with our design and we take full responsibility for getting the problem resolved.


With the current design without the diode, you can short the speaker leads and it will not cause any damage. With the diode you can use any speaker of any ohms. The radio was optimized for 8 ohms impedance but will work fine at any impedance without damaging the radio.

For those that are curious, the design flaw was that the radio gets an inductive kickback which rises above the voltage of a couple of FET switches that are rated at a maximum of 20 volts. Because the inductive kickback is related to the Q of the speaker coil, the inductance of the speaker coil, and the rise time or fall time of the voltage across the speakers, the speaker characteristics play an important part.

Jerry Wanger KK6LFS
http://cs800.blogspot.com