Since I am not measuring any signal directly out of the YTO, I thought perhaps something is wrong with the drive to it instead of a faulty YIG. The drive comes from connector J3 on the A14 board. Below is what I am getting on the J3 connector:
Pin 1: -14.98V (-15V supply voltage)
pin 4: 4.61V (with the connector removed I get 4.96V, not sure if this is a problem;+5V supply)
pin 5: -3.3V (main coil +)
pin 6: -14.98V (main coil -)
pin 8: 14.75V (with the connector removed I get 14.88V, not sure if this is a problem;+15V supply)
pin 9: voltage fluctuates between .5V & 2V (FM- signal)(I read 15mV with the connector removed)
pin 10: voltage fluctuates between .5V & 2V (FM+ signal) (I read 13.6V with the connector removed)
Does any of this seem normal or is something way off base? I'm just not sure what "normal" readings would be on the connector. The attached file is the connector in question.
Any advice or help would really be appreciated.
Thanks!
Tony
Edited by: 4thDoctorWhoFan on Apr 8, 2016 8:01 PM
I have had the same faillure defective YTO.
If you have another analyser with LO out, it's possible to see the call signal in an irregular sequence.
Even a signal generator will do the job. The signal replaces the original YTO frequency.
The signal source has to be steady, so no sweep and about 3,3 GHz.
I have tried this example and surprising some spikes where seen on the CRT.
Conclusion YTO defect.
Maybe it helps you to repair the analyser.
Good luck
Ary