QRP усилитель мощности с заземленной сеткой.
In Japanese CQ magazine , some projects by 7L1OPH (Mr.Yamano) of GG AMP is informed. His AMP had output power about 100W or 500W. I wanted to make them. But I did not have the license to handlel big power. I did not have 10W exciter. Therefore I decided to make QRP GG AMP.
I tried many types of tubes. 6FQ7, 6AV6, 6C4 made no gain. I looked a textbook of NHK (Nippon Hoso Kyoukai). The textbook teached me that the valve must have small Rp (plate resistance) for the GG AMP. The textbook teached me that the valve must have big gm (conductance) for the GG AMP. I have 100 types of tubes. 4GK5 was the tube made to use the tuner of the TV. See the circuit! This AMP was made to use for 50MHz. This AMP has 7dB gain. Maximum power of it was 1.4W. I enjoyed to make GG AMP. I enjoyed the low gain of it.
Kazuhiro Sunamura, (JF1OZL)