Hi Ziv, The SD2933 is an older part - Mouser lists it as 'obsolete' and otherwise unavailable. A review of the datasheets for the two devices (VRF2933, SD2933) reveals that the VRF2933 has a higher drain-source breakdown voltage than the SD2933, and it is tolerant of SWR values up to 70:1. The SD2933 tolerates at least SWR of 3:1, possibly greater, but that is the only spec in its datasheet. The VRF2933 has a somewhat lower gate capacitance than the SD2933. In other respects, the two MOSFETs are very similar.
I suspect the SD2933 will work in place of the VRF2933, but you may need to watch the SWR on your antennas a bit more carefully to avoid exceeding the maximum drain-source breakdown voltage. You will also need to carefully check and adjust the gate bias voltage pots to ensure the proper quiescent drain currents in each MOSFET. 73, Mike, K8CN ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
