Practical question about RF impedance matching:
I have a receiver with an SMA female connector on it. I would like to connect a cheap AM antenna to it.
SMA, like many other connectors, has a 50 ohm impedance, and AM loop antennas tend to have twin-lead outputs at 300 ohms.
All right–I know I need a balun transformer for good efficiency. 300 to 75 ohm transformers are extremely common, but 300 to 50 seems nonexistent. The common 300-75 transformers convert to an F connector, which makes sense since F is typically 75 ohm. I can get F to SMA converters, but they don’t seem to typically include a 75-50 ohm transformer.
So what’s the deal? It seems that if this were a valid thing, it would be easy to find converters. Maybe the difference between 50 and 75 is negligible enough not to matter? Is there something else I’m missing? Thanks.