Приемник прямого преобразования.
Sometimes I indicated on the japanese CQ magazine that some vacuum tube can be used by 12VDC on its plate voltage. That of December 1992 I indicated 6BM8*2 7MHz super radio. That of September 1993 I indicated 12AU7 0-V-1 radio. That of Mai 1996 I indicated 6AJ8 DC radio. In this homepageI will indicate the another product of this idea.
See fig 1! The oscillator is normal grid-tuned-feedback-oscillator. Direct convertor is single balanced product-detector. It is tuned 7MHz. And it has only one stage of audio amplifier. This machine has total 22dB gain. So it needs full size dipole or some kind of good antenna. With this machine and V-dipole, I can hear the 7MHz ssb and cw signal. Because it is constructed by balanced type detector, it has no QRM by 7MHz broadcastings
Kazuhiro Sunamura, (JF1OZL)