6688

The 6688  (European: E180F) (Russian: 6Ж9П) (P/N 154-0215-00) is a miniature high-slope VHF/UHF pentode vacuum tube with a B9A (Noval) miniature 9-pin base, primarily intended "for use in wideband amplifiers in telephone carrier systems, radar equipment and measuring equipment".

It is used in:

• the staircase generator circuit of the 3T77 and 3T77A
• the P80 cathode-follower probe
• TR-4602, Hungarian 551 clone
• the 526
• the 4S2A

Some instruments using part 6688

Instrument	Manufacturer	Class	Model	Description	Introduced
3T77	Tektronix	Plug-in	3T77	Sampling sweep plug-in	1962
3T77A	Tektronix	Plug-in	3T77A	Sampling sweep plug-in	1966
4S2A	Tektronix	Plug-in	4S2A	Dual channel sampling plugin	1965
526	Tektronix	Audio/Video	526	NTSC Vectorscope	1959
P80	Tektronix	Probe	P80	Active probe for 581/585+80	1959
TR-4602	EMG	Oscilloscope	TR-4602	25 MHz dual beam oscilloscope	(?)

Links

• Raytheon CK 6688 Datasheet (PDF)
• 6688 @ radiomuseum.org

Pictures

• 

  P80 probe internal view

Some instruments using part 6688

Instrument	Manufacturer	Class	Model	Description	Introduced
3T77	Tektronix	Plug-in	3T77	Sampling sweep plug-in	1962
3T77A	Tektronix	Plug-in	3T77A	Sampling sweep plug-in	1966
4S2A	Tektronix	Plug-in	4S2A	Dual channel sampling plugin	1965
526	Tektronix	Audio/Video	526	NTSC Vectorscope	1959
P80	Tektronix	Probe	P80	Active probe for 581/585+80	1959
TR-4602	EMG	Oscilloscope	TR-4602	25 MHz dual beam oscilloscope	(?)