Pioneer F-26

{ preliminary }

Extra rare FM tuner and later addition to the Series 20 set of components.

The F-26 was however not a completely new design as it was a repackaged and electronics-wise more modern version of the Japan-only TX-9900 (1974), also available in strict dual-mono layout in the magnificent Exclusive F3 (1976).

The visible part of the quality lies in the resulting stereo separation and s/n specifications : 55dB (1khz) and 83dB (stereo) / 86dB (mono).
We're here in the Sony ST-A7B league for stereo separation (56dB) and even beyond for s/n ratio (75dB / 80dB) !

Features-wise, the only switch available is tied to a back knob which sets the desired muting level between 20 and 40dB. The rest is... bare !

The tuning knob itself acts as resistance : when basic tuning is done and the fingers (assuming one tunes with his fingers...) leave the knob, an automatic fine-tune circuit instantly comes in to precisely lock on the desired frequency with 100Khz precision. The wide/narrow selection is however automatic and cannot be set manually.

The back also holds an FM Auto knob (30...50dB), V + H multipath, DET outputs, plus fixed and variable outputs ; all terminals are gold-plated.

Parts include dual-gate MOS-FETs in the 2-stage RF amp, epoxy PCBs, Pioneer, Hitachi, Fujitsu and Mitsubishi ICs.
The crucial parts (38Khz LPF and parallel balanced linear detector, the latter being the heart of the F-26's ultra specifications) are Pioneer-made, just like the SAW filters.

TX-9900, Exclusive F3 and F-26 : these three versions of same, all very well designed, are however very rare and don't seem to have sold in tangible numbers, even in Japan.
The F-26 is nevertheless part of the all-time design gems. Had it been put in a discrete wood enclosure, it would have been even better.



The catalog used here still isn't translated from japanese to english...