Synchro Signal Frequency changes

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SUMMARY

The forum discussion centers on issues related to synchro signal frequency changes in a glide slope indicator system. The user reports a frequency drop from 400Hz to 1.2KHz when connected to the indicator, despite the system functioning correctly in standalone mode. Key troubleshooting suggestions include checking for load issues, verifying the output with different instruments, and considering the potential for test equipment errors. The discussion emphasizes the importance of using appropriate tools, such as oscilloscopes, for accurate diagnostics.

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  • Understanding of synchro systems and their operation
  • Familiarity with glide slope indicators and their functionality
  • Knowledge of troubleshooting techniques for electronic systems
  • Experience with measurement tools like multimeters and oscilloscopes
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  • Investigate the use of oscilloscopes for analyzing phase relationships in synchro signals
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Electronics engineers, avionics technicians, and anyone involved in troubleshooting glide slope indicator systems or synchro signal outputs.

  • #31
Is it possible that it has been rewired wrongly, or the wrong cables are being used to make the connections.
My suspicion is that the connections to one phase has been reversed by connection to the wrong terminals, or is shorted to ground.
That would give a completely different set of V(s1-s2), V(s2-s3), V(s3-s1) voltages.
Check the connections.
Measure the three voltages relative to the common centre voltage which may not be ground.
 
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  • #32
grasscut said:
I honestly do not have the information. and i really wish i could share more.
i try to make do with what i have and the information you guys had shared with me thus far.
Are you saying that neither unit has a name plate on it? Even a few photos would help. We are too much in the dark to be of real help.
 
  • #33
Baluncore said:
Is it possible that it has been rewired wrongly, or the wrong cables are being used to make the connections.
My suspicion is that the connections to one phase has been reversed by connection to the wrong terminals, or is shorted to ground.
That would give a completely different set of V(s1-s2), V(s2-s3), V(s3-s1) voltages.
Check the connections.
Measure the three voltages relative to the common centre voltage which may not be ground.
It might be the cause where the glide slope indicator itself has wired the S1S2S3 wrongly, but i don't know what's the configuration like. Even if the connection is wrong, will it affect the frequency? because the frequency seems to be quite a drastic change though. I have measured my system output with an angle position indicator and my outputs are correct. Even at the end of the system, i measured the wires of my outputs and it seems fine too. However, the voltage and frequency just changed when its connected to the glide path indicator terminal.

sophiecentaur said:
Are you saying that neither unit has a name plate on it? Even a few photos would help. We are too much in the dark to be of real help.
I just got to know the brand is AGI.
 
  • #34
The lack of certification plates with manufacturer and model numbers suggests it has been scrapped. That may be because it was faulty.
Where did you get it from? Scrapped? Stolen? Junk shop?
The frequency might be bad because you are not measuring the wrong signal or relative to the wrong reference.
When you measure the voltage and frequency, what do you measure it relative to?
What actually is the instrument? Ground or aircraft based? Attitude indicator, turn and bank or glide slope indicator.
Is there a similar instrument on google immages? Can you give us a link or a pictures of your unit?
 
  • #35
Baluncore said:
The lack of certification plates with manufacturer and model numbers suggests it has been scrapped. That may be because it was faulty.
Where did you get it from? Scrapped? Stolen? Junk shop?
The frequency might be bad because you are not measuring the wrong signal or relative to the wrong reference.
When you measure the voltage and frequency, what do you measure it relative to?
What actually is the instrument? Ground or aircraft based? Attitude indicator, turn and bank or glide slope indicator.
Is there a similar instrument on google immages? Can you give us a link or a pictures of your unit?

I measured the voltage and frequency across S1S2, S2S3, S1S3. i did mention that it is glide slope indicator in my previous post
 
  • #36
?8 Insufficient information to progress the matter.
 
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  • #37
@grasscut, without more information and/or pictures we can't help tough any more.

If you get the nameplate data and pictures, send me a PM. Just click on my name and start a conversation.

Until then, this thread is locked.
 
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