diy IF transformers: first attempt.

[Amie]

Now we know the testgear, how are you injecting and sampling the signals? Bearing in mind this can have a big effect on the result.

Hi Jeffrey.

OK, so, function generator set to a max frequency of 490kHz and a sweep width of 50kHz, output checked at this by the counter. Repetition  of sweep for these settings comfortable for the scope horizontal tb set to 0.1mS /div. Output amplitude over this small range is practically constant, and set at 1v. Scope set for vertical amplitude of 10mV/div.

Both "windings" of the experimental IFT are identical, but input fed through 40k source resistance and output to the scope by way of  ×10 probe, (resistive loading at 1M not a problem but input C of ≈20pF knocks it off tune badly, obviously any in circuit strays and loading will have to be allowed for as normal). I would have liked to have used 49pf or 68pf fixed C and 100pF trimmer but although I had some new ones, 9 of the 10 were faulty

Thanks,
Amie.