Projekt TekRep7k - Versionsgeschichte

Wolfgang: /* 04.01.2016 */

2026-01-15T20:47:54Z

04.01.2016

← Nächstältere Version		Version vom 15. Jänner 2026, 20:47 Uhr
Zeile 111:		Zeile 111:

	* Re-Seating all Transistors on the LV-Supply Board Succeeded in completely working LV-Supply, '''HOORAY'''		* Re-Seating all Transistors on the LV-Supply Board Succeeded in completely working LV-Supply, '''HOORAY'''
	* I had bought a bunch om CA3045 chips in case the one on the LV-Supply was damaged		* I had bought a bunch of CA3045 chips in case the one on the LV-Supply was damaged
	*: to check them, I replaced the CA3045 on the LV-Supply by one of the newly acquired => Works the same!		*: to check them, I replaced the CA3045 on the LV-Supply by one of the newly acquired => Works the same!
	* HV-Supply works too ( having replaced the exploded Cap by a 22uF one) !		* HV-Supply works too ( having replaced the exploded Cap by a 22uF one) !
	* after re-assembly, there are 4 connections unconnected because I did not document them at disassembly, DAMN!		* after re-assembly, there are 4 connections unconnected because I did not document them at disassembly, '''DAMN!'''
	* However, the CRT shows a beam, albeit out of focus		* However, the CRT shows a beam, albeit out of focus
	* Tracing the wires shows that two of the open connections are to go to the HV board, which is a pain in the backside because ~~thze~~ HV-supply is so deep inside the oscilloscope		* Tracing the wires shows that two of the open connections are to go to the HV board, which is a pain in the backside because the HV-supply is so deep inside the oscilloscope
	*: One of the 2 connections, however, connects the focus-pot		*: One of the 2 connections, however, connects the focus-pot
	*: The other (P1245 of HV-Supply) connecting 600V to the Storage Control Board (A15)		*: The other (P1245 of HV-Supply) connecting 600V to the Storage Control Board (A15)

Wolfgang: /* 18.12.2015 */

2026-01-15T20:45:44Z

18.12.2015

← Nächstältere Version		Version vom 15. Jänner 2026, 20:45 Uhr
Zeile 101:		Zeile 101:
	* replaced Q869 with an 2N5551. No change.		* replaced Q869 with an 2N5551. No change.
	* However, -50V produces output voltage, although too high (approx. -60V)		* However, -50V produces output voltage, although too high (approx. -60V)
	*: ~~Isuspect~~ a previous owner had it connected to 230V AC or 240V AC but the fine voltage selector was to the lowest of 3 settings.		*: I suspect a previous owner had it connected to 230V AC or 240V AC but the fine voltage selector was to the lowest of 3 settings.

	=== 26.12.2015 ===		=== 26.12.2015 ===

Wolfgang: /* 05.01.2016 */

2016-01-05T21:40:34Z

05.01.2016

← Nächstältere Version		Version vom 5. Jänner 2016, 21:40 Uhr
Zeile 133:		Zeile 133:
	* Delayed Sweep looks OK		* Delayed Sweep looks OK
	* Now to the 2 missing connections: Tracing finds:		* Now to the 2 missing connections: Tracing finds:
	** the longer, coax with blue/white coating connects to the "REMOTE ERASE IN" back panel connector		** the longer, coax with blue/white coating connects to the "REMOTE ERASE IN" back panel connector, leading to P1764 on A15 - "Cal & Storage Circuit Board"
	** the shorter, coax with green/white coating connects to ~~the~~ "EXT SS RESET IN" back panel connector		** the shorter, coax with green/white coating connects to J1047 - "EXT SS RESET IN" back panel connector, leading to P45 on A1 - "Main Interface Board"
			* These resolved, there are 3 issues, put on the backburner for now:
			*# get storage to work, which is broken because of the short circuit in the 600V-line
			*# resolve the "miracle wire" issues. I removed the miracle wire because it seemed wrong
			*# readout does not work for the time being, root cause still unknown

Wolfgang: /* 26.12.2015 */

2016-01-05T18:56:28Z

26.12.2015

← Nächstältere Version		Version vom 5. Jänner 2016, 18:56 Uhr
Zeile 107:		Zeile 107:
	* -50V can be adjusted by R861 from -60V thru -52V, unfortunately not to -50V ...		* -50V can be adjusted by R861 from -60V thru -52V, unfortunately not to -50V ...
	* Page [[Tektronix 7623 Manual]] contains selected parts of the 7623's operators manual, also to be linked from other parts.		* Page [[Tektronix 7623 Manual]] contains selected parts of the 7623's operators manual, also to be linked from other parts.

			=== 04.01.2016 ===

			* Re-Seating all Transistors on the LV-Supply Board Succeeded in completely working LV-Supply, '''HOORAY'''
			* I had bought a bunch om CA3045 chips in case the one on the LV-Supply was damaged
			*: to check them, I replaced the CA3045 on the LV-Supply by one of the newly acquired => Works the same!
			* HV-Supply works too ( having replaced the exploded Cap by a 22uF one) !
			* after re-assembly, there are 4 connections unconnected because I did not document them at disassembly, DAMN!
			* However, the CRT shows a beam, albeit out of focus
			* Tracing the wires shows that two of the open connections are to go to the HV board, which is a pain in the backside because thze HV-supply is so deep inside the oscilloscope
			*: One of the 2 connections, however, connects the focus-pot
			*: The other (P1245 of HV-Supply) connecting 600V to the Storage Control Board (A15)
			* Unfortunately, connecting these 2 results resulted in:
			** No CRT picure at all
			** The HV-Supply case, doubling as the heatsink for the HV primary oscillator transistors, becoming unbearingly hot
			** HV testpoint voltage dropping from ~614V (should be 700V according to manual) to 145V
			* Disconnecting the cable from P1245 improved things: HV supply voltages back to normal, CRT beam back there, focus control working
			* '''TODO:''' find out the cause of the error (most probably another shorted semiconductor)

			=== 05.01.2016 ===

			* Connected a Probe to the 7A18s inputs: Success!
			** Voltage calibration seems to be off because 4V calibrator show up only as 3.6 divisions at 1V/Div amplifier setting
			* Sweep frequency seems OK according to calibrator display
			* Delayed Sweep looks OK
			* Now to the 2 missing connections: Tracing finds:
			** the longer, coax with blue/white coating connects to the "REMOTE ERASE IN" back panel connector
			** the shorter, coax with green/white coating connects to the "EXT SS RESET IN" back panel connector

Wolfgang am 26. Dezember 2015 um 21:58 Uhr

2015-12-26T21:58:07Z

← Nächstältere Version		Version vom 26. Dezember 2015, 21:58 Uhr
Zeile 1:		Zeile 1:
	On ebay I found a Tektronix 7623 Oscilloscope "for Parts" for only 30.- EUR. The 7623 is not the top-of-the-line of the Tektronix 7000 Series and the thing might have been dead as a doornail but for 30 EUR I decided to take the risk and got it sent to me.		On ebay I found a [[Tektronix 7623]] Oscilloscope "for Parts" for only 30.- EUR. The 7623 is not the top-of-the-line of the Tektronix 7000 Series and the thing might have been dead as a doornail but for 30 EUR I decided to take the risk and got it sent to me.

	In my hardware time in the 1980's the Tek 7000 line was sort of the holy grail of oscilloscopes with all high quality features, modular plug-in architecture and a On-Screen readout. Of course it came with the associated steep price tag, so being able to own such a beast even after more that 30 Years and even having to repair it myself sounded very attractive.		In my hardware time in the 1980's the Tek 7000 line was sort of the holy grail of oscilloscopes with all high quality features, modular plug-in architecture and a On-Screen readout. Of course it came with the associated steep price tag, so being able to own such a beast even after more that 30 Years and even having to repair it myself sounded very attractive.

Wolfgang: /* 09.12.2015 */

2015-12-26T21:57:16Z

09.12.2015

← Nächstältere Version		Version vom 26. Dezember 2015, 21:57 Uhr
Zeile 94:		Zeile 94:

	Investigating the LV PS board showed Q872 to be blown. It being a SE7056 and no replacement type specified I thought a MPSA42 could also do the job. So I ordered 20 of these at {{Conrad}}.		Investigating the LV PS board showed Q872 to be blown. It being a SE7056 and no replacement type specified I thought a MPSA42 could also do the job. So I ordered 20 of these at {{Conrad}}.

			=== 18.12.2015 ===

			* MPSA42 have arrived
			* replaced Q872 with an MPSA42. No improvement
			* replaced Q869 with an 2N5551. No change.
			* However, -50V produces output voltage, although too high (approx. -60V)
			*: Isuspect a previous owner had it connected to 230V AC or 240V AC but the fine voltage selector was to the lowest of 3 settings.

			=== 26.12.2015 ===

			* -50V can be adjusted by R861 from -60V thru -52V, unfortunately not to -50V ...
			* Page [[Tektronix 7623 Manual]] contains selected parts of the 7623's operators manual, also to be linked from other parts.

Wolfgang: /* 20.11.2015 */

2015-12-26T19:57:35Z

20.11.2015

← Nächstältere Version		Version vom 26. Dezember 2015, 19:57 Uhr
Zeile 82:		Zeile 82:
	* 2N5551 - 20 Pcs		* 2N5551 - 20 Pcs
	* 2N2905 - 20 Pcs		* 2N2905 - 20 Pcs
	* ~~2N????~~ - 10 Pcs (dual transistor in TO39 package)		* 2N2920 - 10 Pcs (dual transistor in TO39 package)
	* CA3045 (transistor array in DIL14 package) - 3 Pcs		* CA3045 (transistor array in DIL14 package) - 3 Pcs

Wolfgang am 12. Dezember 2015 um 23:34 Uhr

2015-12-12T23:34:47Z

← Nächstältere Version		Version vom 12. Dezember 2015, 23:34 Uhr
Zeile 18:		Zeile 18:
	== Resources ==		== Resources ==

	* ~~{{PubImg\|~~Hardware/MessWerkZeuge/Tektronix_7000}}		* <html><a href="/public/public/Hardware/MessWerkZeuge/Tektronix_7000">Files</a></html>

	== The repair log ==		== The repair log ==

Wolfgang am 12. Dezember 2015 um 23:26 Uhr

2015-12-12T23:26:58Z

← Nächstältere Version		Version vom 12. Dezember 2015, 23:26 Uhr
Zeile 15:		Zeile 15:

	Additionally, [http://w140.com/tekwiki/images/0/0c/Email_address.gif Kurt] at [[http://w140.com/tekwiki/ TekWiki] ([http://w140.com/tekwiki/wiki/7623 The Tekwiki 7623 Page]) did and still does an incredible job in collecting and documenting all things Tektronix.		Additionally, [http://w140.com/tekwiki/images/0/0c/Email_address.gif Kurt] at [[http://w140.com/tekwiki/ TekWiki] ([http://w140.com/tekwiki/wiki/7623 The Tekwiki 7623 Page]) did and still does an incredible job in collecting and documenting all things Tektronix.

			== Resources ==

			* {{PubImg\|Hardware/MessWerkZeuge/Tektronix_7000}}

			== The repair log ==

	=== 02.11.2015 ===		=== 02.11.2015 ===

Wolfgang am 12. Dezember 2015 um 11:06 Uhr

2015-12-12T11:06:22Z

← Nächstältere Version		Version vom 12. Dezember 2015, 11:06 Uhr
Zeile 14:		Zeile 14:


	Additionally, ~~the People~~ at [http://w140.com/tekwiki/wiki/7623 ~~TekWiki~~] did and still do an incredible job in collecting and documenting all things Tektronix.		Additionally, [http://w140.com/tekwiki/images/0/0c/Email_address.gif Kurt] at [[http://w140.com/tekwiki/ TekWiki] ([http://w140.com/tekwiki/wiki/7623 The Tekwiki 7623 Page]) did and still does an incredible job in collecting and documenting all things Tektronix.

	=== 02.11.2015 ===		=== 02.11.2015 ===