I was testing radio link in our city and with mine country house. The testing transceiver was Kenwood TK-760G-1. I am a bit disappointed with the quality of radio link.
The frequency of radio is about 132? ~ 174 MHz. The output power is up to 25W. The transceiver was in high power mode and the antenna burned the hand quite well. The output stage of the radio is built using Mitsubishi RF module M67741H. The output power of the module in 150 … 175 band range is 35W when powered from 12.5V PSU. Inside the module there are two transistors (or maybe amps) and few passive elements. According to diagrams in datasheet, the module maybe can be used in FM band with transmitter like Veronica.
I was using simple quarter wavelength antennas. The link quality was poor. Even when I attached special external antenna placed on the roof. Meanwhile the radio link using old soviet transmitter was ideal. Ant the output power of ÐœÐ°ÑÐº (164MHz) transceiver is only 10…15W. Maybe the reason of it is the sensitivity of receiver? Bur in old radio it is about 0.4 … 0.8Î¼V, while kenwood states 0.25 … 0.33Î¼V. It is strange.
One more interesting moment- old soviet transmitter can be tuned to 0.2Î¼V sensitivity and up to 50W (!) output power without changing components.
Now I need to reprogram Kenwood to other bands and test again. Maybe the used frequency is jammed? I soldered RS232 to TTL converter with MAX232 chip. Also found special software in the internet. While programing I receive “-PC-” on transceiver display and lot of errors on PC. Someone told, that kenwood PC link is very lame and I need to use old PC and exact cable like original one from kenwood. Damn capitalists- they use lame hardware to make user to buy original cables. Hundreds of dollars for fucking few transistor cable…