[time-nuts] EFOS2 Maser acting up :(

[Ole Petter Ronningen]

Corby,

When you write "I.F. Level", I assume you mean the 5.7KHz going to the PLL
- or are you monitoring some other signal?

Re LO; I would expect any issue with the LO would be directly observable on
the output from the Maser - only an isolation amp in between. Have you
measured the EFC on the LO? It could have drifted out of range..

Ole

On Mon, Aug 13, 2018 at 10:10 PM <cdelect at juno.com> wrote:

> Hi,
>
> The EFOS2 Maser is having an "issue", the I.F.level is intermittently
> fluctuating and sometimes drops all the way to zero. I've always wanted
> to see the "raw" output from the cavity so now was my chance! Installed
> two SMA cables  bringing the output of the circulator and the input to
> the LNA out to where I can get at them. Managed to catch it at zero and
> hooked a Spec-A to the output of the circulator. Hooray, The Maser cavity
> output is good, so the problem lies downstream. Installed a directional
> coupler between the two lines looking back into the LNA. Can see a
> healthy 1440 Mhz L.O. leakage and logged a reference level. Now just
> waiting for it to drop again and see if it's the L.O. If not I'll have to
> dive in again and move my monitor SMAs to look at the 19.6...Mhz I.F.
> signal. Pix shows the cavity signal on the spec-A.
>
> Cheers,
>
> Corby_______________________________________________
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