66 block stupidity

I need to find whoever decided to make both 66 blocks with the split down the middle and blocks without it with no identifying mark as to which type is which and pour glitter* over their head.

At left: no split. I’d been putting bridge clips on it for no reason and got a rude surprise (Zeppelin on a country station!) when I expected to have the left three pegs and the right three isolated.

At right: has the split. You have to install bridge clips to join the two sides.

* Biodegradable glitter of course – the sugar or seaweed based kind

2 comments

  1. It’s quite easy to tell them apart. Look at the tap orientation at positions 3/4.

    On the 3/3 split blocks, the orientation of the tabs changes in the middle. The openings on both sides face center.

    On the mult blocks, the leftmost tap faces right, and all others face left, in sync with telco practice of having the main feed on the left, and station taps on the right.

    66 blocks were originally used for 1A2 key systems, and in large systems, a single 25 pair feed might be looped down a column of mult blocks, with each mult block supporting 5 stations.

    It is also worth noting that 2/2/2 blocks also exist, as well as other specialized types, such as feed-thru types with single taps on the face, and wire-wrap pins on the rear.

    https://www.siemon.com/e-catalog/ECAT_GI_page.aspx?GI_ID=66_field-terminated-m-series-s66-blocks

    Bob
    AF6RR

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