The RF Signal Generator IG-102 came on the market in 1963 and was produced until 1977. It was the successor of the RF-1 that came on the market in 1960. There is only minor differences between the RF-1 and the IG-102. Later there was a version IG-102S that differed from the IG-102 in that there was two connectors, marked RF DIRECT, placed right below the main dialing knob. The IGW-19 then replaced the IG-102S but it was only a matter of a new color. The IG-5280 replaced the IG-102 and was produced until 1990 and was a kind of 'low end' or 'beginners' Signal Generator. On my IG-102 I have replaced the connectors to the BNC-type.