SB-2X

The SB-2X is a 2 meter SSB/CW portable, with 1W output. It was sold by Mizuho in the late 1970s, replacing the SB-2M. The rig runs on internal AA cell batteries or from an external 12V DC source. Improvements over the SB-2M included the addition of RIT, an internal charging circuit, and a lighted dial with a momentary switch for the lamp. The SB-2X featured a very sensitive single conversion receiver. The rig was VXO controlled with each of four crystals provding 200kHz of coverage, for a total of up to 800Mhz of the 2m band. This was a huge improvement over the 50KHz per crystal in the older SB-2M. Crystals for 144.000-144.400 were provided from the factory. The SB-2M had a built-in telescopic whip antenna as well as an SO-239 connector on the rear of the radio for use with an external antenna. A Remote connector allows for T/R switching of the matching LA-2X 10W linear amplifier. A carrying case was also available for the SB-2X.

Specifications:

General:
Frequency Coverage:
Four 200kHz segments between 144.000-146.000MHz (144,000-144.400 provided)
Mode: A3J (USB), A1
Frequency Control: VXO
Frequency Stability: within 200Hz per 30 minutes from 60 minutes after power on
Power requirements: 13.5VDC
Power consumption: max. 400mA transmit, 95mA receive with no signal
Size: 188mm(D) x 120mm(W) x 56mm(H)
Weight: 1.6kg

Transmitter:
RF Output Power: 1W (PEP)
Spurious Radiation: less than -60dB
Carrier Suppression: more than 40dB
Unwanted Sideband Suppression: more than 40dB

Receiver:
Receiving System: single conversion
Intermediate Frequency: 9MHz
Sensitivity: less than 0.5µV for 15dB S/N
Selectivity: more than 2.4kHz at -6dB, less than 4.8kHz at -60dB
Audio Output: 1W at 8 ohms

Manual - Japanese with partial English translation (PDF format)
Schematic Diagram (PDF format)
Special thanks to Junichi Nakajima, JL1KRA, for his translation.

-Last updated 10 July 2006