[Elecraft] Case for XG2

[Don Wilhelm]

  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
>
>
>
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