Re: New FT8 Digital Mode Easier on IRF510?

Robert Hudson

Hi John and all

While replacing the final  FET I forgot to put the insulator under the nut holding it to the heat sink case so it was shorted s soon as power was applied and burn’t out the winding on T3.   I rewound it with 0.63mm wire on the original toroid and the wires fitted the centre hole without any problems.    I saw the info  about changing the toroid.    I wonder if it is becoming saturated when using digital modes.   I also learnt to put a 2 amp in the power supply lead , much easier to replace than the FET.    Also my local supplier did not have the original FET but a higher current rating and seems to work well. (IFR-540)  This was not my radio but will purchase one for myself.   Great project kit thanks Adam.

On 13 Aug 2017, at 9:08 am, landrjoh@... [CHINA_QRP] <CHINA_QRP@...> wrote:


Is it acceptable to use a heavier gauge (larger diameter) wire when winding a larger toroid such as the FT50-43?

Thank you,


---In CHINA_QRP@..., wrote :

This is why our recommendation is that you change the ferrite toroid from FT37-43 to FT50-43 or even bigger.

Bob Hudson

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