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It really doesn't have an "adjustment" in it like a lot of SSB radios will have. The same variable-key mod used in a Cobra 29LTD or such works okay in this one. Rather than taking out a jumper wire that leads to the driver stage, this one has a 10 Ohm resistor R20 that feeds modulated power to the driver. Making this resistance value higher, and putting a 100 uF or so electrolytic capacitor across it will provide a reduced, fixed carrier and preserve modulated swing. Putting a NPN darlington power transistor with the capacitor in parallel with it IN PLACE of the 10 ohm resistor will allow variable key just like the Cobra 29/PC-76 etc. radios. There must be a bunch of web pages out there describing how to do that one.
It's a 1978 radio, so I hope it has been stored someplace dry. Once a radio gets to the 25-year mark, stuff starts to go bad just from age. If it was kept somewhere damp, or somewhere really hot, like an attic it could end up needing a bunch of just-plain maintenance. If the channel selector switch gets "noisy", or scratchy inside you could end up on any odd frequency. The PLL chip is unlocked, so simple switch-and-resistor mods will get you a bunch of channels. An intermittent or dirty channel selector will get you lots of wrong channels.
It really doesn't have an "adjustment" in it like a lot of SSB radios will have. The same variable-key mod used in a Cobra 29LTD or such works okay in this one. Rather than taking out a jumper wire that leads to the driver stage, this one has a 10 Ohm resistor R20 that feeds modulated power to the driver. Making this resistance value higher, and putting a 100 uF or so electrolytic capacitor across it will provide a reduced, fixed carrier and preserve modulated swing. Putting a NPN darlington power transistor with the capacitor in parallel with it IN PLACE of the 10 ohm resistor will allow variable key just like the Cobra 29/PC-76 etc. radios. There must be a bunch of web pages out there describing how to do that one.
It's a 1978 radio, so I hope it has been stored someplace dry. Once a radio gets to the 25-year mark, stuff starts to go bad just from age. If it was kept somewhere damp, or somewhere really hot, like an attic it could end up needing a bunch of just-plain maintenance. If the channel selector switch gets "noisy", or scratchy inside you could end up on any odd frequency. The PLL chip is unlocked, so simple switch-and-resistor mods will get you a bunch of channels. An intermittent or dirty channel selector will get you lots of wrong channels.
Need help lost my channel chart . Cobra 148 GTL with a 8719 and 11,1125 crystal 26.175 to 28.045 , Need the chart I can fill in the blanks slide 2ck up and 12 kc down
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