linrad support: A high level mixer with parallel J310 as switches for conversion from HF to 70 MHz.
(Jan 8 2004)
This mixer is very similar to the mixer used in the RX144 unit It is a doubly balanced mixer with four parallel J310 junction FET transistors for each switch. There is a switchable 5 dB attenuator in front of each mixer.

Fig. 1. Schematic diagram for the HF to 70 MHz mixer.

Fig. 2. The second channel is identical. Only the component numbering differs.