Re: New FT8 Digital Mode Easier on IRF510?

Robert Hudson

Thanks Adam

The instruction text says to twist the the wires together and the photo of the toroids shows them in parallel.   I rewound the T3 coil using the method in the photo.   Having come from a motor winding background you need to identify the start and finish of the coils and as such I have seen biflar windings done in 2 different colours which overcomes the problem of getting 2 starts together and hence to finishes.      They transceiver works very well.   

Thanks Bob
On 13 Aug 2017, at 11:20 am, Adam Rong rongxh@... [CHINA_QRP] <CHINA_QRP@...> wrote:

It is true that the wire gauge has little impact to the performance of the transformer. Heavier gauge will have a bit less loss but harder to wind.


于 2017-8-13 8:08, Robert Hudson vk2aor@... [CHINA_QRP] 写道:

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

Bob Hudson  VK2AOR
President CCARC
0415 969 308
Lecture Co-ordinator and Publicity
Wyong Field Day  25thFebruary 2018.

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