Bypassing Battery Connector, Wiring, Fusing and Green-wire problems.



utting NiMH in the existing battery carrier is dangerous because there is no fusing/current-limiting and the springs cause significant voltage. You also have to do the Green wire mod.

 Putting in another complete NiMH pack is a hassle because the connectors are so tiny and the wiring has significant voltage drop.  

Why not avoid all these problems by putting in new wiring from the main board using decent sized wire, inline fuses and a batery-pack connector which is robust and easily obtainable where YOU live, or that matches the Battery Packs YOU have. Then connect a matching plug on your pre-made NiMH pack or make up your own low-resistance-pack by buying cells with solder-tabs on them.  

The connection can be easily made to the Main Board in a way that can be unsoldered in case you have to return it under warranty or when you sell it.  The rear of the Battery-lead socket is easily accessible once the top cover is removed.  The existing bettery lead is left in place in case you need to use it with the standard Battery Pack.

Disconnect all power and batteries.  Remove the top cover.  Position the FT817 with the Front Panel closest to you. On the Main Board you will the the 2-pin Speaker Connector.  Looking towards the back from this connector there are two large electrolytic capacitors.  To the right of the Electrolytic nearest the Loudspeaker Connector you will see 5 pins which come from the other side of the board - this is the back of the socket that the battery cable connects to (yes there is another source of voltage drop here).  

The pin closest to the front is the Green lead.  The next two futher back are the Positive leads and one of these connects to TP1083 - solder the new Positive lead here.  The two closest to the back are the Battery Negative leads - solder the new Negative lead here. Do not solder the Negative lead to the main earth on the PCB - the -ve lead goes via a filter first.


Mike VK2BMM