BA23 Enclosure - Revision history

Jnc: +New category

2024-07-26T15:14:57Z

+New category

← Older revision		Revision as of 15:14, 26 July 2024
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	[[Category: DEC Mounting Boxes]]		[[Category: DEC Mounting Boxes]]
			[[Category: QBUS Hardware]]

Jnc: link to MicroNote online

2024-07-24T01:26:44Z

link to MicroNote online

← Older revision		Revision as of 01:26, 24 July 2024
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	===Termination===		===Termination===

	The BA23 backplane includes removable SIP termination resistors at the bottom. Termination may be 120 ohms or 240 ohms, depending on processor board. Per [[~~DEC~~ MicroNote 35, "~~Q-bus~~ Expansion ~~Concepts~~"]], these termination packs are removed when an expansion chassis is used with the BA23. Keep this in mind when separating an expanded QBus system!		The BA23 backplane includes removable SIP termination resistors at the bottom. Termination may be 120 ohms or 240 ohms, depending on processor board. Per [[MicroNote]] #35, "Backplane Expansion/Termination" (below), these termination packs are removed when an expansion chassis is used with the BA23. Keep this in mind when separating an expanded QBus system!

	==BA23 Internal Cabling==		==BA23 Internal Cabling==
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	* [http://bitsavers.trailing-edge.com/scandocs.trailing-edge.com/micropdp11-volume_2_enclosures-EK-186AA-MG-001.pdf BA23 Enclosure Maintenance] (EK-186AA-MG-001)		* [http://bitsavers.trailing-edge.com/scandocs.trailing-edge.com/micropdp11-volume_2_enclosures-EK-186AA-MG-001.pdf BA23 Enclosure Maintenance] (EK-186AA-MG-001)
			* [https://www.ibiblio.org/pub/academic/computer-science/history/pdp-11/hardware/micronotes/numerical/micronote35.txt Backplane Expansion/Termination]
	* [http://filedump.glitchwrks.com/cap_lists/dec_ba23_aa12131.pdf DEC BA23 AA12131 Power Supply Capacitor List]		* [http://filedump.glitchwrks.com/cap_lists/dec_ba23_aa12131.pdf DEC BA23 AA12131 Power Supply Capacitor List]

	[[Category: DEC Mounting Boxes]]		[[Category: DEC Mounting Boxes]]

Jnc: /* Cooling Considerations */ Avoid redirs

2024-07-23T13:28:14Z

Cooling Considerations: Avoid redirs

← Older revision		Revision as of 13:28, 23 July 2024
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	==Cooling Considerations==		==Cooling Considerations==

	The BA23 uses an airflow path which pulls cooling air through the card cage, into the [[power supply]], and exhausts it through the top (in vertical orientation) or left (horizontal orientation, from the front) side of the chassis through two 120V 120mm fans. The fan closest to the rear of the chassis is mostly responsible for power supply and [[~~QBus~~]] card cage cooling, the fan closest to the front of the chassis handles storage area cooling.		The BA23 uses an airflow path which pulls cooling air through the card cage, into the [[power supply]], and exhausts it through the top (in vertical orientation) or left (horizontal orientation, from the front) side of the chassis through two 120V 120mm fans. The fan closest to the rear of the chassis is mostly responsible for power supply and [[QBUS]] card cage cooling, the fan closest to the front of the chassis handles storage area cooling.

	Operating the BA23 with the I/O panel removed may reduce cooling efficiency, leading to hot running or overheating when running programs which stress the system, such as the [[XXDP]] '''VMJAB0''' memory exerciser, especially in configurations that include a [[KDJ11-B]]. The intake side of the chassis should be kept free from obstructions during operation, as the fans in the output side will pull intake air from the path of least resistance.		Operating the BA23 with the I/O panel removed may reduce cooling efficiency, leading to hot running or overheating when running programs which stress the system, such as the [[XXDP diagnostic package\|XXDP]] '''VMJAB0''' memory exerciser, especially in configurations that include a [[KDJ11-B CPU\|KDJ11-B]]. The intake side of the chassis should be kept free from obstructions during operation, as the fans in the output side will pull intake air from the path of least resistance.

	When operating the BA23 in a rack mounted configuration, ensure adequate intake and exhaust airflow. This often precludes the use of rack side skins.		When operating the BA23 in a rack mounted configuration, ensure adequate intake and exhaust airflow. This often precludes the use of rack side skins.

Glitch: /* BA23 H9278 Backplane */

2024-07-19T12:38:22Z

BA23 H9278 Backplane

← Older revision		Revision as of 12:38, 19 July 2024
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	<br clear=all>		<br clear=all>

			===Termination===

			The BA23 backplane includes removable SIP termination resistors at the bottom. Termination may be 120 ohms or 240 ohms, depending on processor board. Per [[DEC MicroNote 35, "Q-bus Expansion Concepts"]], these termination packs are removed when an expansion chassis is used with the BA23. Keep this in mind when separating an expanded QBus system!

	==BA23 Internal Cabling==		==BA23 Internal Cabling==

Glitch: /* Cooling Considerations */

2024-07-19T12:31:04Z

Cooling Considerations

← Older revision		Revision as of 12:31, 19 July 2024
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	==Cooling Considerations==		==Cooling Considerations==

	The BA23 uses an airflow path which pulls cooling air through the card cage, into the power supply, and exhausts it through the top (in vertical orientation) or left (horizontal orientation, from the front) side of the chassis through two 120V 120mm fans. The fan closest to the rear of the chassis is mostly responsible for power supply and QBus card cage cooling, the fan closest to the front of the chassis handles storage area cooling.		The BA23 uses an airflow path which pulls cooling air through the card cage, into the [[power supply]], and exhausts it through the top (in vertical orientation) or left (horizontal orientation, from the front) side of the chassis through two 120V 120mm fans. The fan closest to the rear of the chassis is mostly responsible for power supply and [[QBus]] card cage cooling, the fan closest to the front of the chassis handles storage area cooling.

	Operating the BA23 with the I/O panel removed may reduce cooling efficiency, leading to hot running or overheating when running programs which stress the system, such as the XXDP '''VMJAB0''' memory exerciser, especially in configurations that include a KDJ11-B. The intake side of the chassis should be kept free from obstructions during operation, as the fans in the output side will pull intake air from the path of least resistance.		Operating the BA23 with the I/O panel removed may reduce cooling efficiency, leading to hot running or overheating when running programs which stress the system, such as the [[XXDP]] '''VMJAB0''' memory exerciser, especially in configurations that include a [[KDJ11-B]]. The intake side of the chassis should be kept free from obstructions during operation, as the fans in the output side will pull intake air from the path of least resistance.

	When operating the BA23 in a rack mounted configuration, ensure adequate intake and exhaust airflow. This often precludes the use of rack side skins.		When operating the BA23 in a rack mounted configuration, ensure adequate intake and exhaust airflow. This often precludes the use of rack side skins.

Glitch: /* Cooling Considerations */

2024-07-19T12:28:57Z

Cooling Considerations

← Older revision		Revision as of 12:28, 19 July 2024
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	==Cooling Considerations==		==Cooling Considerations==

			The BA23 uses an airflow path which pulls cooling air through the card cage, into the power supply, and exhausts it through the top (in vertical orientation) or left (horizontal orientation, from the front) side of the chassis through two 120V 120mm fans. The fan closest to the rear of the chassis is mostly responsible for power supply and QBus card cage cooling, the fan closest to the front of the chassis handles storage area cooling.

			Operating the BA23 with the I/O panel removed may reduce cooling efficiency, leading to hot running or overheating when running programs which stress the system, such as the XXDP '''VMJAB0''' memory exerciser, especially in configurations that include a KDJ11-B. The intake side of the chassis should be kept free from obstructions during operation, as the fans in the output side will pull intake air from the path of least resistance.

			When operating the BA23 in a rack mounted configuration, ensure adequate intake and exhaust airflow. This often precludes the use of rack side skins.

	==External links==		==External links==

Glitch: Adding section for BA23 cooling considerations

2024-07-19T12:23:14Z

Adding section for BA23 cooling considerations

← Older revision		Revision as of 12:23, 19 July 2024
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	You can install three more type A inserts by removing the bracket between the third and fourth cutouts and installing an adapter plate.		You can install three more type A inserts by removing the bracket between the third and fourth cutouts and installing an adapter plate.

			==Cooling Considerations==

	==External links==		==External links==

Glitch: /* BA23 H7864 Power Supply */

2024-07-19T12:20:52Z

BA23 H7864 Power Supply

← Older revision		Revision as of 12:20, 19 July 2024
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	You can increase the fan voltages to +12 Vdc by changing a power supply jumper.		You can increase the fan voltages to +12 Vdc by changing a power supply jumper.
	The [[KA630]] CPU module’s thermal and acoustical specifications for example, are based on the +10 volt setting.		The [[KA630]] CPU module’s thermal and acoustical specifications for example, are based on the +10 volt setting.
	The required fan power does not affect the 230 W output.		The required fan power does not affect the 230 W output.

			=== Capacitor Issues ===

			The BA23 power supply contains one or more RIFA capacitors, which should be replaced before operation. These capacitors fail due to moisture ingress from cracks in the encapsulation. They release great quantities of smoke when they fail.

			The BA23 power supply assembly AA12131, manufactured by Aztec, has been found with leaking general purpose and low ESR capacitors, and should be recapped when disassembled for RIFA replacement. The large capacitors in the fan supply circuit generally do not require replacement, nor do the bulk capacitors immediately after the AC line rectifiers. A capacitor list has been provided in the External Links section.

	==BA23 I/O Panel==		==BA23 I/O Panel==

Glitch: /* External links */

2024-07-19T12:16:26Z

External links

← Older revision		Revision as of 12:16, 19 July 2024
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	* [http://bitsavers.trailing-edge.com/scandocs.trailing-edge.com/micropdp11-volume_2_enclosures-EK-186AA-MG-001.pdf BA23 Enclosure Maintenance] (EK-186AA-MG-001)		* [http://bitsavers.trailing-edge.com/scandocs.trailing-edge.com/micropdp11-volume_2_enclosures-EK-186AA-MG-001.pdf BA23 Enclosure Maintenance] (EK-186AA-MG-001)
	* [http://filedump.glitchwrks.com/cap_lists/dec_ba23_aa12131.pdf~~] (~~DEC BA23 AA12131 Power Supply Capacitor List)		* [http://filedump.glitchwrks.com/cap_lists/dec_ba23_aa12131.pdf DEC BA23 AA12131 Power Supply Capacitor List]

	[[Category: DEC Mounting Boxes]]		[[Category: DEC Mounting Boxes]]

Glitch: /* External links */

2024-07-19T12:15:33Z

External links

← Older revision		Revision as of 12:15, 19 July 2024
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	* [http://bitsavers.trailing-edge.com/scandocs.trailing-edge.com/micropdp11-volume_2_enclosures-EK-186AA-MG-001.pdf BA23 Enclosure Maintenance] (EK-186AA-MG-001)		* [http://bitsavers.trailing-edge.com/scandocs.trailing-edge.com/micropdp11-volume_2_enclosures-EK-186AA-MG-001.pdf BA23 Enclosure Maintenance] (EK-186AA-MG-001)
			* [http://filedump.glitchwrks.com/cap_lists/dec_ba23_aa12131.pdf] (DEC BA23 AA12131 Power Supply Capacitor List)

	[[Category: DEC Mounting Boxes]]		[[Category: DEC Mounting Boxes]]