Scott, Despite the leakage, the XG1 is quite useful for MDS measurements. The calculation given in the manual using readings made at the 1 uV level will come within a dB or two of MDS measurements made using the traditional method of a well shielded, calibrated low level generator followed by a step attenuator. If you wish to use the XG2 for that traditional MDS measurement method, it must be placed in a shielded enclosure, and I believe you should also change the BNC connector because its plastic case would allow sufficient leakage to skew the measurement data.
73, Don W3FPR On 10/29/2010 7:02 PM, Scott Ellington wrote: > That's correct. To measure MDS you have to reduce the XG2 signal with an > external attenuator to around -140 dBm. Leakage from the XG2 into the > receiver by radiation may make that impossible. This also depends on how > well the receiver itself is shielded, as well as how well the cables to it > are filtered, etc. > > One easy way to tell if you have a leakage problem is to actually listen to > the receiver as you increase the attenuation. The signal should quite > abruptly drop below the noise and become completely inaudible. > > I found that with the K3, the leakage from the unshielded XG2 was too high, > though it worked fine with another transceiver. This, of course, is no > shortcoming of the K3; that other transceiver outweighs it about 6 to 1. > > Scott K9MA > > > > On Oct 29, 2010, at 5:46 PM, Matt Zilmer wrote: > >> Probably because polycarbonate is a ineffective shield against stray >> RF exiting the XG2 by radiation rather than conduction. > Scott Ellington > Madison, Wisconsin > USA > > > > ______________________________________________________________ > 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 > ______________________________________________________________ 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
