Difference between revisions of "517"

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The Tektronix 517 is a 50MHz scope [[introduced in 1950]] or [[introduced in 1951|1951]]. The power supply is an external box, like the [[507]], [[551]] and [[555]].
+
{{Oscilloscope Sidebar |
The 517 does not take plug-ins. There is also a 517A.   
+
title=Tektronix 517 |
 +
summary=50 MHz scope |
 +
image=Tek 517 front.jpg|
 +
caption= Tektronix 517 front view |
 +
introduced=1951 |
 +
discontinued=1965 |
 +
manuals=
 +
* [http://w140.com/tek_517_calibration.pdf Tektronix 517 Calibration Guide]
 +
* [http://w140.com/tek_517_early.pdf Early 517 Manual (PDF)]
 +
* [http://w140.com/tek_517_early_OCR.pdf Early 517 Manual (PDF, OCR)]
 +
* [http://w140.com/tek_517_517a_v2.pdf Later Manual Covering the 517 and 517A (PDF)]
 +
* [http://w140.com/tek_517_517a_OCR.pdf Later Manual Covering the 517 and 517A (PDF, OCR)]
 +
 
 +
* [[Media:tek_517_calibration_guide.pdf|Tektronix 517 Calibration Guide (PDF, OCR)]]
 +
}}
 +
The '''Tektronix 517''' is a 50 MHz scope [[introduced in 1950]] or [[introduced in 1951|1951]].
 +
The power supply is an external box, like the [[507]], [[551]] and [[555]].
 +
The 517 does not take plug-ins.
 +
There is also a 517A (1955-1965).
 +
 
 +
==Specifications==
 +
The power consumption of a 517 is 1250 watts.
 +
The indicator unit weighs 76 pounds and the external
 +
power supply weighs 72 pounds.   
 +
 
 +
=== Historic Context ===
 
The 517 closely resembles a scope that Tektronix developed under a contract  
 
The 517 closely resembles a scope that Tektronix developed under a contract  
 
for the US military during 1949 and 1950.  (See link below.)
 
for the US military during 1949 and 1950.  (See link below.)
  
Tektronix engineer Frank Hood recollects:
+
Tektronix engineer [[Frank Hood]] recollects:
 
<blockquote>
 
<blockquote>
"A lot of progress was made in 1949 and 1950. Work was well underway by Logan Belleville, Dick Rhiger and Howard on the high speed scope, the 517. This used some brand new circuitry, distributed (or chain) amplifiers, using 16 to 20 tubes in each stage to get the power needed to handle the high frequencies. Our best prediction at that time was that there were only about 30 to 50 people in the whole world who had need of a scope with 60 to 100 megacycle bandwidth. As it turned out, when we brought out a higher speed scope, people were able to design equipment of greater bandwidth and needed even faster measuring instruments. The cycle was regenerative. Having faster, more accurate measuring tools created a demand for even more measuring tools. We eventually sold several thousand of this instrument."
+
"A lot of progress was made in 1949 and 1950.  
 +
Work was well underway by [[Logan Belleville]], [[Dick Rhiger]] and [[Howard Vollum|Howard]]
 +
on the high speed scope, the 517.
 +
This used some brand new circuitry, [[distributed amplifier|distributed (or chain) amplifiers]],
 +
using 16 to 20 tubes in each stage to get the power needed to handle the high frequencies.
 +
Our best prediction at that time was that there were only about 30 to 50 people in the whole world
 +
who had need of a scope with 60 to 100 megacycle bandwidth.
 +
As it turned out, when we brought out a higher speed scope,
 +
people were able to design equipment of greater bandwidth and needed even faster measuring instruments.
 +
The cycle was regenerative.
 +
Having faster, more accurate measuring tools created a demand for even more measuring tools.
 +
We eventually sold several thousand of this instrument."
 
</blockquote>
 
</blockquote>
  
 +
==Internals==
 +
=== External Power Supply ===
 
The external power supply and oscilloscope are connected by a removable cable
 
The external power supply and oscilloscope are connected by a removable cable
 
with a Jones plug on one end and a Jones socket on the other end.   
 
with a Jones plug on one end and a Jones socket on the other end.   
 
Units with serial numbers from 101 through 1739 use 12-pin Jones 2412 connectors;  
 
Units with serial numbers from 101 through 1739 use 12-pin Jones 2412 connectors;  
after that it is a 16-pin Jones connector. (Was a 16-pin Jones connector used or
+
after that it is a 16-pin Jones connector.  
did they go directory from the 12-pin Jones connector to the 16-pin Amphenol power connector
+
''(Was a 16-pin Jones connector used or did they go directory from the 12-pin Jones connector
used by the [[555]]?) The voltages on the 12-pin connector are:
+
to the 16-pin Amphenol power connector used by the [[555]]?)''
 +
 
 +
The voltages on the 12-pin connector are:
  
* Pin 1: +750V, regulated
+
* Pin 1: +750 V, regulated
* Pin 2: +475V, regulated
+
* Pin 2: +475 V, regulated
* Pin 3: +350V, unregulated
+
* Pin 3: +350 V, unregulated
* Pin 4: +225V, regulated
+
* Pin 4: +225 V, regulated
* Pin 5: +150V, regulated
+
* Pin 5: +150 V, regulated
 
* Pin 6: Ground
 
* Pin 6: Ground
* Pin 7: -250V, regulated
+
* Pin 7: −250 V, regulated
* Pin 8: +180V, unregulated
+
* Pin 8: +180 V, unregulated
  
 
Later 517A units uses the same cable as the [[551]] and [[555]].   
 
Later 517A units uses the same cable as the [[551]] and [[555]].   
 
Although they use the same cable, they are completely incompatible.
 
Although they use the same cable, they are completely incompatible.
 
The voltages are different.  The 517's external power supply
 
The voltages are different.  The 517's external power supply
provides +750V to the indicator unit.  The highest voltage provided by
+
provides +750 V to the indicator unit.  The highest voltage provided by
 
the 555 and 551 power supplies is +500V.  Also, for example, the 517A
 
the 555 and 551 power supplies is +500V.  Also, for example, the 517A
has +180 on pin 8 of the 16-pin connector while the 555 and 551 have
+
has +180 V on pin 8 of the 16-pin connector while the 555 and 551 have
-150V on pin 8.   
+
-150 V on pin 8.   
  
 +
=== Distributed Amplifiers ===
 
The 517 makes extensive use of the [[distributed amplifier]] concept.   
 
The 517 makes extensive use of the [[distributed amplifier]] concept.   
 
Originally the [[5XP]] CRT was used,  
 
Originally the [[5XP]] CRT was used,  
which has 38V/cm vertical deflection sensitivity when operated with 24kV acceleration voltage.  
+
which has 38 V/cm vertical deflection sensitivity when operated with 24 kV acceleration voltage.  
(Is this correct?  It doesn't agree with the 5XP datasheet.)
+
''(Is this correct?  It doesn't agree with the 5XP datasheet.)''
Since the vertical sensitivity at the input connector is 0.1V/cm, we can calculate that  
+
 
 +
Since the vertical sensitivity at the input connector is 0.1 V/cm, we can calculate that  
 
the voltage gain from the input connector to the vertical deflection plates is 380.  
 
the voltage gain from the input connector to the vertical deflection plates is 380.  
For 4cm deflection, a 152-volt differential output swing is required.  There are DC blocking  
+
For 4 cm deflection, a 152 V differential output swing is required.  There are DC blocking  
capacitors at various places in the signal path.  The slowest sweep is 20 us/cm.  The 517 is  
+
capacitors at various places in the signal path.  The slowest sweep is 20 μs/cm.  The 517 is  
 
not designed for low-frequency use.  
 
not designed for low-frequency use.  
 +
 
The vertical signal path is as follows:
 
The vertical signal path is as follows:
  
Line 49: Line 92:
 
* Gain Stage 3: single-ended, seven sections, distributed, [[6AK5]] pentodes  
 
* Gain Stage 3: single-ended, seven sections, distributed, [[6AK5]] pentodes  
 
* Trig Pickoff: one common-cathode [[6CB6]] pentode
 
* Trig Pickoff: one common-cathode [[6CB6]] pentode
* Signal Delay: 51 feet of RG63U 125-ohm coaxial cable
+
* Signal Delay: 51 feet of RG63U 125-ohm coaxial cable (65ns)
 
* Phase Splitter: single-ended in, differential out, three sections, distributed, [[6CB6]] pentode
 
* Phase Splitter: single-ended in, differential out, three sections, distributed, [[6CB6]] pentode
 
* Gain Stage 4: differential, six sections, distributed, [[6CB6]] pentodes
 
* Gain Stage 4: differential, six sections, distributed, [[6CB6]] pentodes
Line 55: Line 98:
  
 
There is a trigger amplifier in the 517 which can take its input from  
 
There is a trigger amplifier in the 517 which can take its input from  
an external source, or  
+
an external source, or from the trigger pickoff in the vertical pre-amp, or  
from the trigger pickoff in the vertical pre-amp, or  
+
from the internal rate generator circuit.  The trigger amplifier circuit has
from the internal rate generator circuit.   
 
The trigger amplifier circuit has
 
 
five stages:
 
five stages:
  
Line 67: Line 108:
 
* Gain Stage 4: single-ended, common-cathode, [[6AG7]] pentode
 
* Gain Stage 4: single-ended, common-cathode, [[6AG7]] pentode
  
The 517 uses 24kV total acceleration voltage on the CRT.  This is generated by the Type 420 High Voltage
+
=== High Voltage Power Supply ===
Power Supply subsystem in the 517.  It uses a 1.8kHz oscillator to produce the high voltage, unlike
+
The 517 uses 24 kV total acceleration voltage on the CRT.   
other Tek scopes which use HV oscillators in the ultrasonic range.
+
This is generated by the [[420|Type 420]] High Voltage Power Supply subsystem in the 517.   
+
It uses a 1.8 kHz oscillator to produce the high voltage,
The power consumption of a 517 is 1250 watts.  The indicator unit weighs 76 pounds and the external
+
unlike other Tek scopes which use HV oscillators in the ultrasonic range.
power supply weighs 72 pounds. 
 
 
 
517 units with serial numbers 101 through 925 use the DuMont 5XP CRT. 
 
Later units use a Tek-made CRT, the T517PxH/T54PxH, where "x" designates
 
the [[phosphor]] type: 1, 2, 7, 11, or 16.  The 5XP has three anode connections:
 
6.6kV, 13.3kV, and 20kV.  The Tek-made CRT has just one anode connection, 20kV,
 
and has 15 V/cm sensitivity at 24kV total acceleration voltage.
 
  
 
The 517 has a switch on the front panel that selects between normal vertical sensitivity,
 
The 517 has a switch on the front panel that selects between normal vertical sensitivity,
which uses the full 24kV acceleration voltage, and "X2" mode, which drops the acceleration
+
which uses the full 24 kV acceleration voltage,  
voltage to 12kV for a doubling of the vertical sensitivity.  The control works by  
+
and "X2" mode, which drops the acceleration voltage to 12 kV for a doubling of the vertical sensitivity.   
switching the the voltage division ratio of the feedback to the error amplifier in the HV supply.
+
The control works by switching the voltage division ratio of the feedback to the error amplifier in the HV supply.
 +
 
 +
== CRTs Used in the 517 ==
 +
517 units with serial numbers 101 through 925 use the [[5XP|DuMont 5XP CRT]]. 
 +
Later units use a Tek-made CRT, the [[T517|T517PxH/T54PxH]], where "x" designates
 +
the [[phosphor]] type: 1, 2, 7, 11, or 16.  The 5XP used [[multi-band acceleration]]
 +
and has three anode connections, at 6.6 kV, 13.3 kV, and 20 kV. 
 +
The Tek-made CRT has just one anode connection, 20 kV,
 +
and has 15 V/cm sensitivity at 24 kV total acceleration voltage.
  
 
The 517 might be the only Tektronix instrument to have a part made of wood.
 
The 517 might be the only Tektronix instrument to have a part made of wood.
Line 89: Line 131:
 
the probe power.
 
the probe power.
  
In 1965, following the introduction of the 50MHz [[547]], the
+
== Comparison of 517 with 547 ==
517 was discontinued. The 547 uses a non-distributed solid-state vertical
+
In 1965, following the introduction of the 50 MHz [[547]], the 517 was discontinued.
amplifier, [[tunnel diodes|tunnel diode]] triggering, and a 6.5 V/cm CRT,  
+
The 547 uses a non-distributed solid-state vertical amplifier,
 +
[[tunnel diodes|tunnel diode]] triggering, and a 6.5 V/cm CRT,  
 
thereby achieving good performance with
 
thereby achieving good performance with
 
lower cost, size, weight, complexity, and power consumption than the 517.
 
lower cost, size, weight, complexity, and power consumption than the 517.
  
 
+
{| border="1" class="wikitable" style="text-align: center;"
{| border="1" style="text-align: center;"
 
 
|+ Comparison of 517A with 547
 
|+ Comparison of 517A with 547
 
! scope="col" |
 
! scope="col" |
! scope="col" | 517A
+
! scope="col" width="33%" | 517A
! scope="col" | 547 with 1A1
+
! scope="col" width="33%" | 547 with 1A1
 
|-
 
|-
 
! scope="col" | Bandwidth
 
! scope="col" | Bandwidth
| 50MHz
+
| 50 MHz
| 50MHz
+
| 50 MHz
 
|-
 
|-
 
! scope="col" | Sensitivity
 
! scope="col" | Sensitivity
Line 118: Line 160:
 
|-
 
|-
 
! scope="row" | Weight
 
! scope="row" | Weight
| 148 pounds
+
| 148 lb / 67 kg
| 71 pounds
+
| 71 lb / 32 kg
 
|-
 
|-
 
! scope="row" | Complexity
 
! scope="row" | Complexity
Line 126: Line 168:
 
|-
 
|-
 
! scope="row" | Power Consumption
 
! scope="row" | Power Consumption
| 1250 watts
+
| 1250 W
| 510 watts
+
| 510 W
 
|}
 
|}
  
Line 135: Line 177:
 
since a fast scope requires a fast pulse generator to test it.
 
since a fast scope requires a fast pulse generator to test it.
  
 +
The [[P170CF]] cathode-follower probe was designed for use with the 517.
 +
 +
== Links==
 
* [http://w140.com/tektronix_milspec_high_speed_scope_OCR.pdf Final Report on Tektronix MILSPEC High Speed Scope (PDF, cleaned up and OCR)]
 
* [http://w140.com/tektronix_milspec_high_speed_scope_OCR.pdf Final Report on Tektronix MILSPEC High Speed Scope (PDF, cleaned up and OCR)]
 
* [http://w140.com/tektronix_milspec_high_speed_scope.pdf Final Report on Tektronix MILSPEC High Speed Scope (5MB, PDF, cleaned up)]  
 
* [http://w140.com/tektronix_milspec_high_speed_scope.pdf Final Report on Tektronix MILSPEC High Speed Scope (5MB, PDF, cleaned up)]  
 
* [http://w140.com/MILSPEC_High_Speed_Scope.pdf Final Report on Tektronix MILSPEC High Speed Scope (220MB, PDF, original)]
 
* [http://w140.com/MILSPEC_High_Speed_Scope.pdf Final Report on Tektronix MILSPEC High Speed Scope (220MB, PDF, original)]
* [http://w140.com/tek_517_calibration.pdf Tektronix 517 Calibration Guide]
 
* [http://w140.com/tek_517_early.pdf Early 517 Manual (PDF)]
 
* [http://w140.com/tek_517_early_OCR.pdf Early 517 Manual (PDF, OCR)]
 
* [http://w140.com/tek_517_517a_v2.pdf Later Manual Covering the 517 and 517A (PDF)]
 
* [http://w140.com/tek_517_517a_OCR.pdf Later Manual Covering the 517 and 517A (PDF, OCR)]
 
 
* [http://w140.com/flynn_johnson_fast_gray_wedge.pdf Flynn and Johnson "Fast Grey Wedge Analyzer for High Input Rates"]
 
* [http://w140.com/flynn_johnson_fast_gray_wedge.pdf Flynn and Johnson "Fast Grey Wedge Analyzer for High Input Rates"]
 
* [http://w140.com/thomas_and_hearst-measurement_of_exploding_wire_energy.pdf Thomas and Hearst, "An Electronic Scheme for Measurement of Exploding Wire Energy"]
 
* [http://w140.com/thomas_and_hearst-measurement_of_exploding_wire_energy.pdf Thomas and Hearst, "An Electronic Scheme for Measurement of Exploding Wire Energy"]
  
 +
==Pictures of 517 ==
 +
<gallery>
 +
517_cat_whole.jpg|front
 +
517_cat_int_left.jpg|bottom internal
 +
517_cat_int_right.jpg|right internal
 +
517_cat_int_top.jpg|top internal
 +
517_cat_ps_int.jpg|power supply internal
 +
517 power connector.jpg|12-pin Jones socket on power supply
 +
Jones 12pin male.jpg|12-pin Jones plug
 +
Tek 517 jones plug.jpg|Original Tek 517 cable with Jones plug
 +
Jones 12m inside.jpg|12-pin Jones plug inside
 +
Tek 517 420 hv.jpg|High voltage supply
 +
Tek 517 front.jpg|Front view
 +
Tek 517 indicator jones.jpg|12-pin Jones connector on indicator unit
 +
Tek 517 left.jpg|Left internal view
 +
Tek 517 vert output.jpg|Distributed vertical output amplifier
 +
Tek 517 wood cap support.jpg|Wooden support for capacitor C826
 +
Tek crt table.png|Tek CRT Reference Chart
 +
517 trig amp underside.jpg
 +
517 vert stages one through three.jpg
 +
517 4th vert stage.jpg
 +
517 right internals.jpg
 +
517 timing switch 2.jpg
 +
517 timing switch 1.jpg
 +
517 power test point.jpg
 +
517 hv osc.jpg
 +
Tek 517a vert pre.png | Vertical pre-amplifier circuit
 +
Tek 517a vert amp.png | Vertical amplifier circuit
 +
Tek 517a trigger amp.png | Trigger amplifier circuit
 +
Tek 517 late sweep.png |
 +
Tek 517a crt circuit.png | CRT circuit
 +
Tek 517a trigger rate gen.png |
 +
Tek 517 hvps2.png | High-voltage power supply circuit
 +
517 ps fan.jpg
 +
517 ps bottom left.jpg
 +
517 ps bottom right.jpg
 +
517 ps front left int.jpg
 +
517 ps right rear bottom.jpg
 +
517 ps bottom.jpg
 +
517 ps right int.jpg
 +
517 assembly2.jpg
 +
B170_A.JPG| [[B170-V|B170-V 170 Ω attenuator]]
 +
Tek 517 ad.jpg
 +
517a rear vert interface.jpg|Direct CRT access mod
 +
517a single sweep controls.jpg|Single-sweep mod
 +
Tek 517 735 on cart.jpg
 +
Tek 517 735 left.jpg
 +
Tek 517 735 front.jpg
 +
Tek 517 735 front upper.jpg
 +
Tek 517 735 front lower.jpg
 +
Tek517 Scope01.jpg
 +
Tek517 Scope02.jpg
 +
Tek517 Scope03.jpg
 +
Tek517 Scope04.jpg
 +
Tek517 Scope05.jpg
 +
Tek 517 lvps internal.jpg
 +
517 PowerSupply01.jpg
 +
517 Cable PS-Scope.jpg
 +
517 Cable Conn.jpg
 +
517 Cable Conn2.jpg
 +
Tek 517 with 5xp crt.jpg|517 with [[5XP]] CRT
 +
Tek 517 right internal 5xp.jpg|517 with [[5XP]] CRT
 +
Tek 517 early rear chassis.jpg
 +
Tek 517 early bottom.jpg
 +
Tek 517 early bottom rear.jpg
 +
Tek 517 early bottom front.jpg
 +
Tek 517 crt gun connections.jpg
 +
</gallery>
 +
 +
==Pictures of 517A ==
 
<gallery>
 
<gallery>
Image:517_cat_whole.jpg|front
+
517A_1.JPG |517A Front
Image:517_cat_int_left.jpg|bottom internal
+
517A_2.JPG |517A Power Supply
Image:517_cat_int_right.jpg|right internal
+
6_57.JPG |517A with cart
Image:517_cat_int_top.jpg|top internal
 
Image:517_cat_ps_int.jpg|power supply internal
 
Image:517 power connector.jpg|12-pin Jones socket on power supply
 
Image:Jones 12pin male.jpg|12-pin Jones plug
 
Image:Jones 12m inside.jpg|12-pin Jones plug inside
 
Image:Tek 517 420 hv.jpg|High voltage supply
 
Image:Tek 517 front.jpg|Front view
 
Image:Tek 517 indicator jones.jpg|12-pin Jones connector on indicator unit
 
Image:Tek 517 left.jpg|Left internal view
 
Image:Tek 517 vert output.jpg|Distributed vertical output amplifier
 
Image:Tek 517 wood cap support.jpg|Wooden support for capacitor C826
 
Image:Tek crt table.png|Tek CRT Reference Chart
 
Image:517 trig amp underside.jpg
 
Image:517 vert stages one through three.jpg
 
Image:517 4th vert stage.jpg
 
Image:517 right internals.jpg
 
Image:517 timing switch 2.jpg
 
Image:517 timing switch 1.jpg
 
Image:517 power test point.jpg
 
Image:517 hv osc.jpg
 
Image:Tek 517a vert pre.png
 
Image:Tek 517a vert amp.png
 
Image:Tek 517a trigger amp.png
 
Image:Tek 517 late sweep.png
 
Image:Tek 517a crt circuit.png
 
Image:Tek 517a trigger rate gen.png
 
Image:517 ps fan.jpg
 
Image:517 ps bottom left.jpg
 
Image:517 ps bottom right.jpg
 
Image:517 ps front left int.jpg
 
Image:517 ps right rear bottom.jpg
 
Image:517 ps bottom.jpg
 
Image:517 ps right int.jpg
 
Image:517 assembly2.jpg
 
Image:B170_A.JPG| 170 ohms Attenuator
 
File:Tek 517 ad.jpg
 
File:517a rear vert interface.jpg|Direct CRT access mod
 
File:517a single sweep controls.jpg|Single-sweep mod
 
 
</gallery>
 
</gallery>
 +
 +
[[Category:Monolithic tube scopes]]
 +
[[Category:Introduced in 1950]]

Latest revision as of 19:43, 9 September 2020

Manuals – Specifications – Links – Pictures

The Tektronix 517 is a 50 MHz scope introduced in 1950 or 1951. The power supply is an external box, like the 507, 551 and 555. The 517 does not take plug-ins. There is also a 517A (1955-1965).

Specifications

The power consumption of a 517 is 1250 watts. The indicator unit weighs 76 pounds and the external power supply weighs 72 pounds.

Historic Context

The 517 closely resembles a scope that Tektronix developed under a contract for the US military during 1949 and 1950. (See link below.)

Tektronix engineer Frank Hood recollects:

"A lot of progress was made in 1949 and 1950. Work was well underway by Logan Belleville, Dick Rhiger and Howard on the high speed scope, the 517. This used some brand new circuitry, distributed (or chain) amplifiers, using 16 to 20 tubes in each stage to get the power needed to handle the high frequencies. Our best prediction at that time was that there were only about 30 to 50 people in the whole world who had need of a scope with 60 to 100 megacycle bandwidth. As it turned out, when we brought out a higher speed scope, people were able to design equipment of greater bandwidth and needed even faster measuring instruments. The cycle was regenerative. Having faster, more accurate measuring tools created a demand for even more measuring tools. We eventually sold several thousand of this instrument."

Internals

External Power Supply

The external power supply and oscilloscope are connected by a removable cable with a Jones plug on one end and a Jones socket on the other end. Units with serial numbers from 101 through 1739 use 12-pin Jones 2412 connectors; after that it is a 16-pin Jones connector. (Was a 16-pin Jones connector used or did they go directory from the 12-pin Jones connector to the 16-pin Amphenol power connector used by the 555?)

The voltages on the 12-pin connector are:

  • Pin 1: +750 V, regulated
  • Pin 2: +475 V, regulated
  • Pin 3: +350 V, unregulated
  • Pin 4: +225 V, regulated
  • Pin 5: +150 V, regulated
  • Pin 6: Ground
  • Pin 7: −250 V, regulated
  • Pin 8: +180 V, unregulated

Later 517A units uses the same cable as the 551 and 555. Although they use the same cable, they are completely incompatible. The voltages are different. The 517's external power supply provides +750 V to the indicator unit. The highest voltage provided by the 555 and 551 power supplies is +500V. Also, for example, the 517A has +180 V on pin 8 of the 16-pin connector while the 555 and 551 have -150 V on pin 8.

Distributed Amplifiers

The 517 makes extensive use of the distributed amplifier concept. Originally the 5XP CRT was used, which has 38 V/cm vertical deflection sensitivity when operated with 24 kV acceleration voltage. (Is this correct? It doesn't agree with the 5XP datasheet.)

Since the vertical sensitivity at the input connector is 0.1 V/cm, we can calculate that the voltage gain from the input connector to the vertical deflection plates is 380. For 4 cm deflection, a 152 V differential output swing is required. There are DC blocking capacitors at various places in the signal path. The slowest sweep is 20 μs/cm. The 517 is not designed for low-frequency use.

The vertical signal path is as follows:

  • Optional B170-V external input attenuator
  • Gain Stage 1: single-ended, six sections, distributed, 6AK5 pentodes
  • Gain Stage 2: single-ended, six sections, distributed, 6AK5 pentodes
  • Gain Stage 3: single-ended, seven sections, distributed, 6AK5 pentodes
  • Trig Pickoff: one common-cathode 6CB6 pentode
  • Signal Delay: 51 feet of RG63U 125-ohm coaxial cable (65ns)
  • Phase Splitter: single-ended in, differential out, three sections, distributed, 6CB6 pentode
  • Gain Stage 4: differential, six sections, distributed, 6CB6 pentodes
  • Gain Stage 5: differential, twelve sections, distributed, 6CB6 pentodes

There is a trigger amplifier in the 517 which can take its input from an external source, or from the trigger pickoff in the vertical pre-amp, or from the internal rate generator circuit. The trigger amplifier circuit has five stages:

  • Phase Splitter: 6J6 dual-triode connected as a differential amplifier
  • Gain Stage 1: single-ended, three sections, distributed, 6AK5 pentodes
  • Gain Stage 2: single-ended, three sections, distributed, 6AK5 pentodes
  • Gain Stage 3: single-ended, common-cathode, 6AG7 pentode
  • Gain Stage 4: single-ended, common-cathode, 6AG7 pentode

High Voltage Power Supply

The 517 uses 24 kV total acceleration voltage on the CRT. This is generated by the Type 420 High Voltage Power Supply subsystem in the 517. It uses a 1.8 kHz oscillator to produce the high voltage, unlike other Tek scopes which use HV oscillators in the ultrasonic range.

The 517 has a switch on the front panel that selects between normal vertical sensitivity, which uses the full 24 kV acceleration voltage, and "X2" mode, which drops the acceleration voltage to 12 kV for a doubling of the vertical sensitivity. The control works by switching the voltage division ratio of the feedback to the error amplifier in the HV supply.

CRTs Used in the 517

517 units with serial numbers 101 through 925 use the DuMont 5XP CRT. Later units use a Tek-made CRT, the T517PxH/T54PxH, where "x" designates the phosphor type: 1, 2, 7, 11, or 16. The 5XP used multi-band acceleration and has three anode connections, at 6.6 kV, 13.3 kV, and 20 kV. The Tek-made CRT has just one anode connection, 20 kV, and has 15 V/cm sensitivity at 24 kV total acceleration voltage.

The 517 might be the only Tektronix instrument to have a part made of wood. There is a wood support for a large electrolytic capacitor, C826, which filters the probe power.

Comparison of 517 with 547

In 1965, following the introduction of the 50 MHz 547, the 517 was discontinued. The 547 uses a non-distributed solid-state vertical amplifier, tunnel diode triggering, and a 6.5 V/cm CRT, thereby achieving good performance with lower cost, size, weight, complexity, and power consumption than the 517.

Comparison of 517A with 547
517A 547 with 1A1
Bandwidth 50 MHz 50 MHz
Sensitivity 50 mV/cm 50 mV/cm
Cost in 1964 $3500 $2475
Size scope + power supply all in one
Weight 148 lb / 67 kg 71 lb / 32 kg
Complexity 130 tubes 45 tubes
Power Consumption 1250 W 510 W

Some 517 modification kits are listed on page 181 of the 1959 catalog.

Tek sold the 108 pulse generator as a tool for maintaining the 517, since a fast scope requires a fast pulse generator to test it.

The P170CF cathode-follower probe was designed for use with the 517.

Links

Pictures of 517

Pictures of 517A