Ten-Tec Model 208 Audio CW Bandpass Filter for the Argonaut 509 Transceiver

The Model 208 CW Filter is an accessory audio bandpass filter intended for use with the Ten-Tec Argonaut transceiver. It consists of the Model 245 printed ciruit assembly mounted in a small enclosure, along with a three position selector switch and attached cable. The 208 plugs directly into the Argonaut Model 509 ACCESSORIES socket, whereas a slight modification is necessary when using the filter with the older Model 505 Argonaut. Service Note SN-6-505 details the modifications.

• Bandwidth: 150 Hz @ -3 dB, 1.45 kHz @ -60 dB in CW-1 position; 260 Hz @ -3 dB, 2.8 kHz @ -20 dB in CW-2 position
• Shape Factor: 7.2 to 1 @ 6/60 dB points
• Center Frequency: 750 Hz
• Input Impedance: 220 k
• Output Impedance: Less than 10 ohms
• Insertion Gain: 2.5 dB
• Semiconductors: 2 ICs
• Powered by Transceiver - +12 VDC @ 2 mA