[evlatests] doppler tracking

[Ken Sowinski]

On Mon, 23 Jul 2007, Gustaaf van Moorsel wrote:

> 1 - Any even number of Hertz (including, of course, '0') in the
>     flukes leads to excellent data on all baselines
>
> 2 - Any odd number of Hertz in the flukes leads to no fringes on
>     crossed baselines

Might this be related to the fact that we have 1 Hz tuning
resolution for IFs A and D, but only 2 Hz for IFs B and C?