![]() | If you're interested in these boards, contact erco@seriss.com with the email Subject: "1A2 82B block inquiry" and I can supply ordering info for fully assembled/tested boards. Try to include info on which phone models you expect to use with the board, and any other details/questions you can think of. |
Here's a video showing how to set up and test a 4A speakerphone system with a 2565 using the Seriss 82B block:
In place of an "Option Plug", the Seriss 82B uses a more conventional 8-position jumper to select between these two features:
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Ring Cut-Off - Option "A" This option cuts off the phone's ringer while the speakerphone is in use. |
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Auxiliary Relay - Option "B" This option enables ringing during a speakerphone call, and causes a switch closure between KSU pins 25 and 50 while the speakerphone is in use, which can be used, for instance, to turn on a "Speakerphone In Use" lamp at a secretary's desk. |
NOTE: Not all 1A2 key telephone sets support speakerphone. Some key sets lack the violet pairs on the station cable. This can usually be visually confirmed by looking at a 5 line phone's amphenol connector and checking if the violet pair pins are missing.
Also, as described in the above video, some phones supporting speakerphone might have been modified by a previous installer to spare off the violet pairs (where they've been isolated and taped off) to support bridging. In such cases, to restore the phone for speakerphone use, you must move the violet pairs back to the factory defaults terminal screws. I've highlighted the violet pairs in these BSP schematics for the 2565HK/HKM and 2565GKMS model phones to aid in restoring their factory defaults (Click to view large schematics):
![]() 2565HK/HKM |
![]() 2565GKMS |
For more info on the 82B connection block, its options and its option screws, refer to: BSP 512-700-100 "4A Speakerphone System".
Also, for each telephone set that supports 4A speakerphones, there's usually a section that describes wiring considerations specific to that phone set, e.g. 565 and 2565 model sets: BSP 512-720-405 "565- and 2565 Set Connections / Speakerphone System 4A".
The left hand side labeled "ON" and "OFF" is basically a large rocker switch:
The 108B speaker has a cable with a partial amphenol connector that connects to the 82B block, giving it access to the selected phone line over the phone set's violet pairs, control signals from the 680A transmitter through the 82B connection block, and 18VAC power from the terminals on the connection block.
While the 4A speaker system is pretty good at preventing "feedback", it's still best to keep the 680A transmitter at least a foot or two away from the speaker to prevent feedback issues that can cause the unit to mute itself.
This connects to the 82B connection block's screw terminals labeled "AC", and provides power to both the 108B speaker's internal amplifier circuit and 680A transmitter's power switch and power lamp.
Here's the 82B (REV A) Sprint Layout file (.lay6), the Gerber (.gbr) and Drill (.drl) files in a zip, and a BOM Parts List. Note that the male amphenol, AMP1, needs two small slots machined by hand to accept the notched mini-amphenol connectors from the 108A speakerphone and 608A transmitter. Notching the connector is described below under the "Board Assembly" instructions.
All of the parts are usually available from Digikey. The amphenols can sometimes be in short supply, and can be ordered directly from the manufacturer, TE Connectivity. Solder-type amphenols can also be used in place of the press-fit type connectors.
![]() Hakko CHP DP-24-N Depaneling Tool |
![]() Nibbler slot cutting size |
![]() Align nibbler with 2nd pin from each end to cut slots. |
![]() Amphenol with "nibbled" slot |