[AdrianH]

This should be my last post on this and this is just a measure to see how it performs with the home made transformer.

Not really sure how others check out responses, but I am using a Com120B radio test set to both generate the tone and measure it, it has wide band settings in the audio section. I also used a 4 Ohm resistive load, rather than annoy the wife.

I set up at 1KHz to provide 5% distortion through the amp, (as setting I was used to using in PMR)
The test set will measure dBm into 4 Ohms, then with a constant set output went down and up to 20KHz output frequency.

20Hz 10.2 dBm*
50Hz 17.1 dBm*
100Hz 19.1 dBm*
200Hz 20.2 dBm*
250Hz 20.4 dBm
500Hz 21.0 dBm
1KHz 21.2 dBm
2KHz 21.4 dBm
4KHz 21.5 dBm
5KHz 21.5 dBm
8KHz 21.4 dBm
10KHz 21.2 dBm
15KHz 20.3 dBm
16KHz 20.1 dBm
20KHz 19.0 dBm

* I could notice some distortion on the waveform at these frequencies suspect hitting saturation, a sort of flat topping of the sine wave but only on peaks.

Looking OK to me, no not hi-fi but not that bad, I hope the roll off is down to the cap I put in across an input to knock off top end, but for my first attempt at winding a transformer, I will be trying again when i build a better amp and will try to understand more of the theory and practical aspects of it.

Adrian