82

From TekWiki
Revision as of 15:37, 10 October 2021 by Peter (talk | contribs)
(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)
Jump to navigation Jump to search
Tektronix 82
85 MHz Dual trace amplifier
Type 82 front view (earlier style)

Compatible with 580-series scopes

Produced from 1962 to 1972

Manuals


Manuals – Specifications – Links – Pictures

The Tektronix Type 82 is a dual-trace plug-in for the 580-series scopes. The Type 82 combined with a 585 or 585A provides a 4 nanosecond risetime (85 MHz bandwidth).

Key Specifications

Rise time 4 ns in ×1 mode, 4.3 ns in ×10 mode (in 585 mainframe)
Bandwidth 85 MHz in ×1 mode, 80 MHz in ×10 mode (in 585 mainframe); 70 MHz/66 MHz, respectively, with P6008 probe
Deflection 50 V/Div to 100 mV/Div in ×1 mode, 5 V/Div to 10 mV/Div in ×10 mode (1-2-5)

Internals

The front end of the Type 82 has three versions, depending on serial number range. In all versions, the signal path starts with a 7586 nuvistor cathode-follower, followed by bipolar diff-amps and diode channel switching, followed by a distributed output amplifier made of three 6DJ8 tubes, with differential 93 Ω outputs.

The use of a distributed amplifier in a plug-in is unusual. Note that the 58x series differs from 500-series scopes mainly in that the vertical signal interface between the plug-in and the mainframe is a low controlled impedance (93 ohms), as opposed to other 500-series scopes that present a high impedance to the plug-in.

Stan Griffiths wrote:

If you feed [a fast risetime] signal into an early type 82, you will find that the top three least sensitive positions have really terrible frequency response ... so bad, in fact, that some customers thought they were broken. When told this was normal, these customers wondered why Tek ever included them on the plugin. The answer was that they were still useful for low frequency signals ... but Tek never really made it well known that these 82 attenuator positions were lousey. I think this was fixed on the later 82's as Tek learned how to make better attenuators. If you have an early 82 and need to look at high frequency signals on the less sensitive ranges, the answer is to get ×100 probes and use them on the more sensitive ranges where the frequency response is better.

The P6008 voltage probe was designed for use with the Type 82.

The 585 manual warns that for proper performance with the 82 and higher-numbered plug-ins, 585 non-A scopes with serial numbers before 2585 should have the back termination of the final distributed amplifier output modified to the later circuit (modification 040-275).

Prices

Year 1965 1969 1971*
Type 82 $650 $695 $925
2020 value $5,340 $4,900 $5,910
* "Limited demand" instrument

Pictures


Some Parts Used in the 82

Page Class Description Used in
6DJ8 Vacuum Tube (Dual Triode) dual triode 132 502 502A 503 504 515 516 519 529 RM529 533 535 543 544 545 545A 545B 546 547 549 555 556 565 581 581A 585 585A 661 2A60 2A63 3A7 3A8 1121 1A4 67 81 82 86 3B1 3B4 1S1 B O W Z Telequipment S32A Telequipment D52 Telequipment TD51 Telequipment S52 Telequipment S51 Telequipment Type A
7586 Vacuum Tube (Triode) Nuvistor triode 1A1 1A2 1A5 10A2 10A2A 11B1 11B2A M 321 321A 3A74 3T77 6R1A 3A1 3A3 3A5 3A6 3A8 3A74 3S76 3T77A 4S1 6R1 82 86