UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post - FT-101ZD DC converter query

Mike. Watterson · 3rd Aug 2019, 8:31 pm

I don't think any of the MkIII version have the socket. My MKII had the connector and my MkIII does not.
You can see that the HT inverter is pretty simple from looking at the circuit and hardly more than a transistorised vibrator pack.

The current draw is pretty severe. Moding to use 12V for LT direct and mains from 12V inverter might make more sense.

I've used my FT101ZD MkII and then my MkIII on generators. Unless you have a running vehicle with heavy duty battery and alternator the DC operation isn't very practical.

I think that's why it was discontinued with the MkIII. Certainly all earlier models I seen have the connector even without the "DC Converter box" which is little more than two transistors on a heatsink with a couple of caps.
Connections are +12V, 0V, push pull drive (x2) and feedback windings to bases (x2).
It's well documented on the FoxTango group.

3rd Aug 2019, 8:31 pm	#3
Mike. Watterson Heptode Join Date: Dec 2014 Location: Limerick, Ireland. Posts: 901	Re: FT-101ZD DC converter query I don't think any of the MkIII version have the socket. My MKII had the connector and my MkIII does not. You can see that the HT inverter is pretty simple from looking at the circuit and hardly more than a transistorised vibrator pack. The current draw is pretty severe. Moding to use 12V for LT direct and mains from 12V inverter might make more sense. I've used my FT101ZD MkII and then my MkIII on generators. Unless you have a running vehicle with heavy duty battery and alternator the DC operation isn't very practical. I think that's why it was discontinued with the MkIII. Certainly all earlier models I seen have the connector even without the "DC Converter box" which is little more than two transistors on a heatsink with a couple of caps. Connections are +12V, 0V, push pull drive (x2) and feedback windings to bases (x2). It's well documented on the FoxTango group.