I meant OFF and not ON for the internal preamp. I don't use internal preamp ON.
The issue is most internal preamps are not designed for 160m, they need to cover up to 50 MHz Even the ICOM Norton preamp does not have the muscle to handle the signals level on 160m. If you turn << OFF >> you internal preamp and use a better preamp outside the radio with a good BPF or pre-selector you will always have the flexibility to adjust the system NF reducing RF gain. But there is no way to improve NF, it is all about less degradation of the signal to noise ratio. _________________ Topband Reflector Archives - http://www.contesting.com/_topband