５０MHｚのＳＳＢをやるための親受信機である。コンバータのイメージ比が取りやすいこと、いつも実際の交信が聞こえて調整に便利なことから周波数帯は７MHｚとした。１９７６年～７７年にこれを製作した当時のラインナップは6AH6(mix),
6AU6 (VFO)-MF (国際MF45510AZ)- 6BA6*2- 6BE6 (DET), 12AU7(BFO)-6BM8 オール真空管だった。その後性能アップのためミクサを７３６０、VFOを２SK19*2、検波をSN16913、AFアンプをLM380に変更した。時間を掛けたのはAGCで、回路方式や定数は何年もいじくりまわしたと思う。MOS-FET（３SK35,45,53）のコンバータ群をつなぎ、サイクル２１の６ｍバンドでアジア、北米、南米、オセアニア、アフリカなど多くのDX信号を捉えた思い出深い受信機で、現在は２５０Hz
X’talフィルタも搭載し、７MHｚのQRPP交信にも使用している。
7.00-7.24MHz SSB (2.3kc), CW (250Hz), S/N more than 10dB (0dBµV input),
image ratio 70dB, AC100V
This is the receiver to connect a VHF converter to do VHF-SSB. Because
the image ratio of the converter is better, and an actual contact is always
easy to catch, I set a frequency band to 7MHz and it was very convenient
for an adjustment of making. Line-up was 6AH6 (mix) and 6AU6 (VFO) -MF(kokusai
MF45510AZ) - 6BA6*2- 6BE6 (DET) and 12AU7 (BFO)-6BM8, It was all vacuum
tube ! when this was made in 1976-77. Later, I chose RCA7360 for the mixer
and VFO of 2SK19*2 and detector of SN16913 (Gilvert cell) and the AF amplifier
were changed to LM380. I think it was AGC that I spent much time to improve
on this receiver. The circuit system and the fixed number were modified
for years. Asia, North America, South America, Oceania and Africa, this
receiver worked in a pair with MOS-FET converters, and caught many DX signals
on 6m band of cycle 21. A 250Hz X'tal filter is loaded and it's being also
used for a QRPP work of 7MHz at present.
7.00-7.24MHz SSB (2.3kc), CW (250Hz), S/N more than 10dB (0dBµV input),
image ratio 70dB, AC100V
