Re: E4401B No 50MHZ Cal signal
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Hi Jon,
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Yes, I see an IF signal coming out of A8J3 when I follow the RF verification procedure when using an *external* 50 MHZ source.? The signal does very with attenuation, as describe in the service guide.?
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-- Mike
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Can you see a 21.7Mhz IF signal on the cable plugged into A3J2?? I was looking over pages 55 - 75 of the ESA Service guide for a E4401B and there is a verification process to check
on RF deck function.? I only suggest this because your original message stated your seeing signals but wasn't sure if they were as expected in Amplitude and correct frequency.??
On Saturday, March 30, 2019, 12:58:42 PM CDT, Tom B <tbryan@...> wrote:
Did you make sure the cal signal was turned on?? You can turn it off on the E4401B.
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On 3/30/2019 1:39 PM, Michael Williams wrote:
Hi Mark,
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Thanks for the reply and the thoughts.
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From the info in my CLIP, the 50 MHZ CAL signal is generated by dividing the 800 MHZ 2nd LO by 16.? The 2nd LO gets its power from
the TEST MUX (U56).? This mux is dead ¨C no enable signal, no activity on any of the control lines.? That¡¯s where I¡¯m stuck, I can¡¯t figure out if it¡¯s a hardware or software issue that is causing the 2nd LO to not get turned on.? The CLIP is not
very clear on what tells the fractional divider (U55) to enable it.
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The 10MHz reference clock is the timing source for the 800 MHZ 2nd LO, and is present, both internally and at the 10MHZ output connector in
the back.
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Thanks again,
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Mike
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