> >I would like to keep my new Daiwa CN-801 (UHF connectors) SWR Power > >meter in the Tx line permanently. Is this a good idea? It is > > No; the power sensing diode may generate IMD.
The IMD problem seems to happen very dependent on the sampler type and location. After talking with some of the gang at Telewave and a few other mfgrs I've found they and I both feel it's best to avoid un unprotected diode type power sampler on a wideband (view to the outside world) coax line. So the simple fix in a basic system might be just to park a quality bandpass cavity in front of the sensor unit. Depending on how you adjust the cavity... the reading will still be relative. cheers, s.