Fitting RotaTone to a GPO 706 / 746 / 8746 – And TrimPhone 722
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Here is how a converted GPO 706 / 746 / 8746 should be wired before RotaTone is fitted.
Note A – Rectifier no. 205 – should already be fitted, email us if you require one.
Note B – 3.3k resistor – should be fitted (if required), if not there will be a strap/link. A 3.3kΩ REN should be fitted if your telephone has 2 x 500Ω bell coils. If there are 2 x 2000Ω bell coils, only a strap/link is required.
A GPO 706 / 746 / 8746 fitted with RotaTone and Polarity Guard
Note: If you have terminal 19A and/or 19B – The RotaTone red wire can be terminated there and no link wire on the underside of the board is required.
The 706 RotaTone fitting is the same as the (8)746 for all components, except the link wire. Then there are 2 options depending whether or not a circuit board is present on your 706.
706 Link wire placement – No circuit board model – 2 images – Both taken before RotaTone is fitted.
… then attach the other end here.
RotaTone location – 706 – ‘No circuit board’ model.
RotaTone location – 706 – ‘Circuit board’ model.
RotaTone location – (8)746
Solder a small solder eyelet to each of the Orange, White and Brown leads of the RotaTone. Note: Ensure the white wire, that connects to the D4 terminal on the dial is not touching any other terminal.
* On some of the newer dials, the 5 terminal are laid out in reverse order. When disconnecting the original dial loom, note how the orange, pink and brown cables are connected. The orange, white and brown of the RotaTone connect to the same terminals (pink=white).
Clean dial contacts to ensure RotaTone works exactly as it should.
The 3 points to clean are shown below. As you can see, one of the sets is in a closed position already so can be cleaned by running the cleaning strip between them a few times. The other 2 sets can be closed by turning the dial, then cleaned.
White dial wire, D4 solder lug adjustment.