New project. Back in the day (1962) Johnson sold the Messengers. They were used for base or mobile operation. The messenger 1 was a 5 channel crystal controlled 27Mhz CB. Many of them were converted to the "Business band" and utilized in Taxi cabs, plus other small business applications. When used in a vehicle, the Messenger used a vibrator power supply, switching the vehicles 6 or 12vdc system to generate the CB's power requirements. These days, the radios are pretty much worthless, since there are so many new small transceivers on the market. So, my friend Scott and I brainstormed the subject. He has one that we will be converting to 10 meter AM band, utilizing a DDS VFO. His will run as a transceiver using the offset function of the fancy VFO. The offset is required to shift frequency 455kc's for the receive section. I am changing mine over to the 40 meter band, AM and CW. My Messenger will only be a transmitter. With some tweeking, this little guy can put out 10 watts! Heres another fun fact, The messenger oscillator does not multiple frequency. Therefore when it was a CB, the transmit crystal was cut for the actual channel, ex: 27.085 (channel 11). So, as a 40 meter transmitter, it will use the direct frequency from the VFO. Ex: 7.290 Mhz. Using the Johnson VFO-122, this transmitter could be used on the 40 or 80 meter band. A cool monobander transmitter! I will be playing with this project and posting more info. Yes, this is far from a guitar amp, but gives you some insight on modification of old obsolete electronics!
8 мар 2024