Interesting. How would you measure the impedance the sdr rx or even the K3, for that matter adds to the circuit? I often wondered this when tuning a bandpass filter, to work with a receiver, using a return loss bridge, how can you be sure the rx is 50ohm...?
73 Dean On Sun, Dec 5, 2021, 6:27 PM Michael Tope <[email protected]> wrote: > Yeah, unless the splitter is active, the isolation is only going to be > as good as the source match (i.e. VSWR looking back toward the RF out > port of the K3). The devil is always in the details. > > 73, Mike W4EF........... > > On 12/5/2021 1:48 PM, Jim Brown wrote: > > On 12/5/2021 1:18 PM, Joe Subich, W4TV wrote: > >> This only works 1) if the SDR impedance is consistently high from > >> 100 KHz to 54 MHz and 2) the SDR has excess gain to compensate for > >> the loading from the K3 receiver. > >> > >> However without a splitter, there is no protection for the K3 receiver > >> against spurious signals generated by the SDR! > > > > YES! And that, along with the stub-aspect of the loop to an > > unterminated load, are the reasons for using one of the MiniCircuits > > hybrid splitters. Note, however, that they are passive devices, and > > like all passive devices, depend on all ins and outs be properly > > terminated to meet isolation specs. > > > > 73, Jim K9YC > > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[email protected] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to [email protected] > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [email protected]
