L: Difference between revisions

1,614 bytes added ,  22 November 2019
m
Details about D5972
No edit summary
m (Details about D5972)
(4 intermediate revisions by 3 users not shown)
Line 11: Line 11:
* [http://w140.com/tek_fcp/tek_type_l_factory_cal_proc.pdf Tektronix Type L Factory Calibration Procedure (PDF)]
* [http://w140.com/tek_fcp/tek_type_l_factory_cal_proc.pdf Tektronix Type L Factory Calibration Procedure (PDF)]


* [[Media:070-336.pdf|Tektronix Type L Manual (PDF, OCR)]]
* [[Media:070-336.pdf|Tektronix Type L Manual (PDF, OCR, bad-OCR)]]
* [[Media:tek_type_l_fcp.pdf|Tektronix Type L Factory Calibration Procedure (PDF, OCR, bad-OCR)]]
* [[Media:tek_type_l_fcp.pdf|Tektronix Type L Factory Calibration Procedure (PDF, OCR, bad-OCR)]]
}}
}}
Line 33: Line 33:


{{MissingSpecs}}
{{MissingSpecs}}
==Internals==
The input is switched via a Frequency compensated attenuator network which is controlled by the Vols/CM Switch.
Input is then coupled to first cathode follower V5832, a 5654/6AK5W RF Pentode.
The screen supply of this  cathode follower is switched from +100 to a decoupled network from +225V rail when the X10 Mode is selected.
The output of input amplifier is then switched via a 10X Amplifier - if the X10 mode is selected in the front panel - or directly to the paraphase or phase inverter made up of two [[12AU6]] tubes. This stage converts the input signal to a differential push-pull output. This output is passed to the final output drivers, which are two cathode follower sections with a pair of [[12AT7]] tubes. The differential output is then passed to pin 1 and 3 of the connector to drive the vertical amplifier inside the chassis.
The 10X amplifier stage is built with 3 5654/6AK5W tubes. First two are configured as amplifier and the last one as  output cathode follower.
Diode D5972 on the first 5654/6AK5W amplifier V5942 tube's cathode is used to protect the cathode bypass capacitor C5972. C5972 is a 500 μF/6V cathode bypass Capacitor.
In case someone pulls out V5942 and power on the plug-in, the cathode bias of -150V will come across C5972 and can potentially destroy it. This diode is used to prevent such scenarios and to drive the voltage to ground via R1958 (12K) if such condition occurs. 
Heater for the tubes are derived from +75VDC heater supply available at pin 15 of the connector. This is to avoid any interference/hum from the regular AC heater supply at 60Hz.


==Pictures==
==Pictures==
Line 42: Line 58:
Tek type l left.jpg
Tek type l left.jpg
Tek type l bottom.jpg
Tek type l bottom.jpg
Tek type l top2.jpg
Tek type l in 541a.jpg|Type L in [[541|541A]]
Tek type l in 541a.jpg|Type L in [[541|541A]]
Tek type l perf.png | Performance in Different Scopes
Tek type l perf.png | Performance in Different Scopes
1,537

edits