TG501: Difference between revisions

Revision as of 14:02, 10 December 2021

Tektronix TG501
time mark generator Tektronix TG501 Produced from 1974 to 1995 Manuals Tektronix TG501 Manual (OCR, stitched schematics) Tektronix TG501 Schematics, stitched (All manuals in PDF format unless noted otherwise)

Manuals – Specifications – Links – Pictures

The Tektronix TG501 is a time mark generator plug-in for the TM500 system.

There is also a TG501A.

Note the output must be terminated into 50 Ω or there may be no signal at all.

Key Specifications

Interval	1 ns to 5 s in 1−2−5 sequence
Timing accuracy	Stability 1×10^-5, long-term drift 1×10^-5 per month (with Option 1, 5×10^-7 / 1×10^-7 per month)
Error Readout	Accuracy 1 digit (±0.1% points), Range to ±7.5%
Amplitude	≥1 V peak on 5 s through 10 ns; ≥750 mV_p-p on 5 ns and 2 ns; ≥200 mV_p-p on 1 ns (separate output) (all into 50 Ω)
Trigger Output	Slaved to marker output from 5 s through 100 ns. Remains at 100 ns for all faster markers
External Reference Input	1 MHz, 5 MHz or 10 MHz; TTL compatible (internally hard wired so output frequencies counted down to 1 MHz)

Rear Interface Signals

Connector Pin		Description
Signal	Return	Description
28A	27A	Marker Out (requires front BNC disconnection)
27B	28B	Trigger Out (requires front BNC disconnection)
25A	26A	Internal 1 MHz Clock Out (TTL)
24B	25B	External Clock Input
26B	22B	Data Good (High when BCD data valid)
17A..20A	22B	bit 4..1 BCD Display data, MSD
21A..24A	22B	bit 4..1 BCD Display data, LSD
16A	22B	Fast=Low, Slow=High

Internals

The TG501 internally produces a 1 MHz reference clock, either from an internal crystal oscillator, or from an externally supplied frequency.

A 100 MHz VCO is phase-locked to this reference frequency (in fixed-frequency mode) or to the output of a variable 1 MHz astable multivibrator (in variable frequency mode). When the variable oscillator is in use, its frequency is digitally compared to the fixed 1 MHz reference and displayed as a deviation in percent with a pair of LEDs indicating the sign (fast or slow).

A chain of dividers running off the 100 MHz clock provide the selectable output markers.

Links

See the TG501/Repairs page for repair information.
Tek TG501A Time Mark Gen Restoration by NFM @ YouTube
TG501 Repair and Calibration by Zenwizard Studios @ YouTube
TG501 In-Depth Troubleshooting of a Stubborn Unit by Zenwizard Studios @ YouTube

Pictures

TG501

TG501 early version
TG501 late version
TG501 early version
TG501 early version
TG501 output waveform

TG501A

@@ Line 1: / Line 1: @@
 {{TM500 | mfg=Tektronix | type=TG501 | function=time mark generator | class=pulse generator | image=Tek tg501 on.JPG | introduced=1974 | discontinued=1995 |
-designers= |manuals=
+manuals=
-* [http://w140.com/smb/TG501_SM.pdf Tektronix TG501 Manual (OCR, PDF)]
+* [[Media:070-1576-02.pdf|Tektronix TG501 Manual]] (OCR, stitched schematics)
-* [[Media:TG501 schematics.pdf|Tektronix TG501 Schematics (stitched, PDF)]]
+* [[Media:TG501 schematics.pdf|Tektronix TG501 Schematics, stitched]]
 }}
 There is also a TG501A.
-Note the [http://www.eevblog.com/forum/repair/tektronix-tg501-out-put-problem/ output must be terminated into 50 Ω] or there may be no signal at all.
+Note the [https://www.eevblog.com/forum/repair/tektronix-tg501-out-put-problem/ output must be terminated into 50 Ω] or there may be no signal at all.
 {{BeginSpecs}}
@@ Line 16: / Line 16: @@
 {{Spec | External Reference Input | 1 MHz, 5 MHz or 10 MHz; TTL compatible (internally hard wired so output frequencies counted down to 1 MHz) }}
 {{EndSpecs}}
+==Rear Interface Signals==
+{| class="wikitable"
+|-
+! colspan="2" | Connector Pin
+! rowspan="2" | Description
+|-
+! Signal
+! Return
+|-
+| 28A      || 27A || Marker Out (requires front BNC disconnection)
+|-
+| 27B      || 28B || Trigger Out (requires front BNC disconnection)
+|-
+| 25A      || 26A || Internal 1 MHz Clock Out (TTL)
+|-
+| 24B      || 25B || External Clock Input
+|-
+| 26B      || 22B || Data Good (High when BCD data valid)
+|-
+| 17A..20A || 22B || bit 4..1 BCD Display data, MSD
+|-
+| 21A..24A || 22B || bit 4..1 BCD Display data, LSD
+|-
+| 16A      || 22B || Fast=Low, Slow=High
+|}
+==Internals==
+The TG501 internally produces a 1 MHz reference clock, either from an internal crystal oscillator, or from an externally supplied frequency.
+A 100 MHz VCO is phase-locked to this reference frequency (in fixed-frequency mode) or to the output of a variable 1 MHz astable multivibrator (in variable frequency mode).
+When the variable oscillator is in use, its frequency is digitally compared to the fixed 1 MHz reference and displayed as a deviation in percent with a pair of LEDs indicating the sign (fast or slow).
+A chain of dividers running off the 100 MHz clock provide the selectable output markers.
 ==Links==
+* See the [[TG501/Repairs]] page for repair information.
 * [https://www.youtube.com/watch?v=U5LQpqwqNIU Tek TG501A Time Mark Gen Restoration] by NFM @ YouTube
-* See the [[TG501/Repairs]] page for repair information.
+* [https://www.youtube.com/watch?v=FIe9WzdIZ9g TG501 Repair and Calibration] by Zenwizard Studios @ YouTube
-* [https://www.youtube.com/watch?v=FIe9WzdIZ9g Zenwizard Studios - TG501 Repair and Calibration]
+* [https://www.youtube.com/watch?v=rF5V7D0VZeE TG501 In-Depth Troubleshooting of a Stubborn Unit] by Zenwizard Studios @ YouTube
-* [https://www.youtube.com/watch?v=rF5V7D0VZeE Zenwizard Studios - TG501 In Depth Troubleshooting of a Stubborn Unit.]
 ==Pictures==
+===TG501===
+<gallery>
+Tek tg501 on.JPG          | TG501 early version
+Tg 501 late.jpg           | TG501 late version
+Tek tg501 internal1.jpg
+Tek tg501 internal2.jpg
+Tek tg501 internal3.jpg
+Tek tg501 internal4.jpg
+Tek tg501 internal5.jpg
+Tek tg501 internal6.jpg
+Tek tg501 internal7.jpg
+Tek tg501 early left.jpg  | TG501 early version
+Tek tg501 early right.jpg | TG501 early version
+Tek tg501 waveform.jpg    | TG501 output waveform
+</gallery>
+===TG501A===
 <gallery>
-Tek tg501 on.JPG|TG501 early version
+Tek tg501a.jpg
-Tg 501 late.jpg|TG501 late version
-Tek tg501a.jpg|TG501A
-Tek tg501 waveform.jpg |TG501 output waveform
-Tek tg501 internal1.jpg|TG501
-Tek tg501 internal2.jpg|TG501
-Tek tg501 internal3.jpg|TG501
-Tek tg501 internal4.jpg|TG501
-Tek tg501 internal5.jpg|TG501
-Tek tg501 internal6.jpg|TG501
-Tek tg501 internal7.jpg|TG501
-Tek tg501 early left.jpg|TG501 early version
-Tek tg501 early right.jpg|TG501 early version
 </gallery>
 [[Category:Time mark generators]]