Seriss Corporation - 1A2 Key Phone System Equipment

 1A2 "Single Board" KSU
These boards are an easy "single circuit board" solution to managing multiline "1A2" business phones popular in the 1950's - 1980's in the United States and other countries, collectively called "key systems".

The current version of this board is REV-J6A.

Board revisions are, in progression of new-to-old:
J6A, J5A, J5, J4, J3, J2, J1, H / H1, G1, G, F1, F, E, B.

You can see the entire revision history which describes in great detail what's different in each board revision.

If you're interested in these boards, contact erco@seriss.com with the email Subject: "1A2 KSU Inquiry" and I can supply ordering info for fully assembled/tested boards. Include info on which phone models you expect to use with the board.

Amphenol ⇌ RJ45 Cable Reducer & Expander
These boards let you use simple RJ45 cat5/cat5e network cabling to interconnect 1A2 phones to the Seriss KSU without needing 25 pair cables or 66 blocks.

Lines 1,2,3 and 5 as well as bells and buzzers can be carried over three RJ45 cables without any special punch blocks or configuration. Fewer cables can be used for fewer lines. (Line 4 is not supported; to fully support 5 lines or more, you should use 25 pair cable.)

Designed mainly for use between 1A2 phones and the Seriss KSU. Click here for details.

If you're interested in purchasing these boards, contact erco@seriss.com with the email Subject: "1A2 RJ45 amphenol adapters inquiry" and I can supply ordering info for fully assembled/tested boards.

Seriss 82B Connection Block
(for 4A Speakerphones)
This Seriss 82b connection block board is a modern re-implementation of the Western Electric 82b connection block used to interconnect 4a speakerphone components with 1A2 key telephone sets, such as the 565 / 2565 Western Electric sets, and the 5 line Touch-A-Matics.

If you're interested in purchasing 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.

Include your phone set model# and 4A speakerphone components you plan you use. Example: a 2565 phone set with a 108a speaker, 680a transmitter, 85B1 power unit. Make sure speaker and transmitter have intact connectors at the ends of their cables!