The 10dB attenuator is probably recommended as it will help to improve the VSWR of the source impedance of the sig gen that is used to test the 8473C detector. This will help to minimise the overall mismatch uncertainty of the test system and this will give more consistent performance.?
?
You can use other attenuator values, but a 6dB attenuator won't improve the source impedance as well as a 10dB attenuator. Obviously, you would need to use a decent quality attenuator rated for the frequency range of interest, and this will need to be a very special part if you wanted to test up at frequencies beyond 18GHz. Otherwise the VSWR of the attenuator might actually be worse than the VSWR of the signal generator up at 18GHz or so.
?
A healthy 8473C will already have an internal termination resistance of about 50 ohms so it shouldn't need an extra external dc path to ground at its input. It should be possible to measure the resistance of the input with a DMM to make sure it is OK and undamaged.?
?
?
