005: 144 to 2400MHz transverter (JA3GCT board)

b. 局発出力とMixer出力にそれぞれI/D型BPFを追加
c. mixerをrat-race型のSBMからDBMに変更
d. 受信入力端にisolator追加
e. 受信トップをGaAsFETからHEMTに変更
f. MGF0904-MGF0905の2段アンプを追加
2400-2402MHz, 2424-2426MHz Pout 3.5W spurious -55dB NF 2.6dB/28dB gain DC13.5V

After I bought 2.4GHz transverter board of a KEN electronics, several problems appeared. Therefore I was obliged to make some modification soon. The problem was mainly concerned with the stability and spurious of the local oscillator (54 times multiplied of 42MHz crystal oscillator). I remember that I remade the oscillator units (up to 376MHz) three times. I decided to use 2,256MHz that is 48times multiplied of 47MHz after all. The purious level was finally cleared the aiming level by addition of the inter-digital BPF. Because I made many modification as following, the original part of the KEN electronics became only the straight amplifier of 2,400MHz after all.

1.local oscillator
2. inter-digital BPF
3. mixer changed from rat-race type of SBM to DBM
4. isolator was added
5. GaAsFET was changed to HEMT
6. two stage power amplifier added (MGF0904-0905) making was in 1992.

2400-2402MHz, 2424-2426MHz Pout 3.5W spurious radiation -55dB NF 2.6dB/28dBgain DC13.5V





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