Difference between revisions of "L"

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title=Tektronix Type L |
 
title=Tektronix Type L |
 
summary=High sensitivity amplifier plugin |
 
summary=High sensitivity amplifier plugin |
image=type L front.jpg |
+
image=Tek type l front.jpg |
 
caption=Tektronix Type L |
 
caption=Tektronix Type L |
 
introduced=1957 |
 
introduced=1957 |
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* [http://w140.com/mmm/tek-l.pdf Tektronix Type L Manual (PDF)]
 
* [http://w140.com/mmm/tek-l.pdf Tektronix Type L Manual (PDF)]
 
* [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, bad-OCR)]]
 +
* [[Media:tek_type_l_fcp.pdf|Tektronix Type L Factory Calibration Procedure (PDF, OCR, bad-OCR)]]
 +
* [[Media:Tek type l cal outline.pdf|Tektronix Type L Calibration Outline (PDF, OCR)]]
 
}}
 
}}
 
The '''Tektronix Type L''' is an amplifier plug-in for [[500-series scopes]].
 
The '''Tektronix Type L''' is an amplifier plug-in for [[500-series scopes]].
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{{MissingSpecs}}
 
{{MissingSpecs}}
 +
 +
==Internals==
 +
 +
The input signal traverses a frequency-compensated attenuator network controlled by the Volts/cm switch,
 +
and is then coupled to the first cathode follower tube (V5832), a [[5654]]/[[6AK5W]] RF pentode.
 +
The screen supply of this cathode follower is switched from +100 V to a decoupling
 +
network fed from the +225 V rail when the ×10 Mode is selected.
 +
 +
The output of input amplifier is then switched via a 10× amplifier (if ×10 mode is selected) 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 ×10 amplifier stage is built with three 5654/6AK5W tubes, the first two of which are configured as
 +
amplifiers, and the last one as an output cathode follower.
 +
 +
The diode D5972 on the first 5654/6AK5W amplifier tube's cathode (V5942) is used to protect the cathode bypass capacitor C5972, a 500 μF/6 V electrolytic, in case someone would pull out V5942 with power applied,
 +
in which case the cathode bias of −150 V would come across C5972 and destroy it. 
 +
 +
Heater supplies for the tubes are derived from the +75 V<sub>DC</sub> supply available at pin 15 of
 +
the mainframe interface, to avoid any mains interference/hum from the regular AC heater supply.
  
 
==Pictures==
 
==Pictures==
  
 
<gallery>
 
<gallery>
 +
type L front.jpg
 
Tek type l.jpg
 
Tek type l.jpg
 
Tek type l top.jpg
 
Tek type l top.jpg
 
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

Latest revision as of 11:15, 5 May 2021

Manuals – Specifications – Links – Pictures

The Tektronix Type L is an amplifier plug-in for 500-series scopes.

The Type L is a Type K plus a 10x-gain AC-coupled preamp that extends the maximum sensitivity to 5 mV/div. Bandwidth in a 545 is 30 MHz at 50 mV/div and above, 3 Hz-24 MHz at 20 mV/div and below.

Type 53/54L was introduced in 1957 along with the 536 and its companion 53/54T sweep plug-in. It was renamed the Type L in 1959. It was the fastest 5 mV plug-in until the 1A1 in 1964. It was dropped after 1972.

K, L, and T are tied for longest production life, at 16 years. B, D, and G are next at 15 years.

Late versions have a BNC connector instead of a UHF connector.

Lavoie Laboratories produced an unauthorized clone, the LA-265-L.

Specifications

please add

Internals

The input signal traverses a frequency-compensated attenuator network controlled by the Volts/cm switch, and is then coupled to the first cathode follower tube (V5832), a 5654/6AK5W RF pentode. The screen supply of this cathode follower is switched from +100 V to a decoupling network fed from the +225 V rail when the ×10 Mode is selected.

The output of input amplifier is then switched via a 10× amplifier (if ×10 mode is selected) 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 ×10 amplifier stage is built with three 5654/6AK5W tubes, the first two of which are configured as amplifiers, and the last one as an output cathode follower.

The diode D5972 on the first 5654/6AK5W amplifier tube's cathode (V5942) is used to protect the cathode bypass capacitor C5972, a 500 μF/6 V electrolytic, in case someone would pull out V5942 with power applied, in which case the cathode bias of −150 V would come across C5972 and destroy it.

Heater supplies for the tubes are derived from the +75 VDC supply available at pin 15 of the mainframe interface, to avoid any mains interference/hum from the regular AC heater supply.

Pictures