Sorry to take up bandwidth here, but I'm trying to modify an old CB amp
to use with the K3.
It has a pair of MRF 455s. I've rewound the input transformer to 4:1 and
amended the capacitors across both input and output transformers.
I've put a bias supply with a standing current of 200MA. It is putting
out 100 watts but is very non linear. It is also nowhere near 50 ohms
impedance on the input as the SWR at best is 2:1 and on some bands awful:1.
I suspect the problem lies with the transformers, the cores of which I
have no information. Has anyone on list had any experience with this PA
design. What should the inductance of the input and output transformers
be and is the nonlinearity due perhapd the tranformers not being man
enough for the job.
Any answers direct to me off list would be much appreciated. May need to
order some transformers from Communications Concepts.
73
John G3YPZ
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