Page last updated 27th April 2018
Crystal Filter Switching
The photos below is a PIN diode switched SSB & AM crystal filter board. As well as filter switching, the transmit and receive paths can also be switched making it useful in a transceiver application. Hence the four SMA connectors.... Transmit in & out as well as Receive in & out.
RF Power Meter with Auto Ranging SWR
The photos below show my implementation of a circuit that can be found on the web. It's a dual range wattmeter with a peak hold function as well as an SWR meter. The SWR meter does not need to be set for full scale in order to make an SWR reading. A directional coupler for the frequencies of interest is also required for RF sampling purposes.
The circuit below does not include the calibration potentiometers which are connected to the FWD & REF out. The upper half if the circuit is the related to the SWR function.
HYCAS I.F. Amplifer
HYCAS info not yet added!