FAQ X-108G The difference in the sensitivity of the transceiver with different IF filters. (1 Viewer)

[Alexandr 2000]

• Hello everyone I want to ask if anyone has checked the sensitivity of this transceiver with different IF filters? I checked in CW mode with a 2.3kHz 50mkV filter from the generator, the S-meter shows S=9, and when the 0.5kHz filter is turned on, the same signal is determined by the S-meter as S=6. Is it a malfunction? Or is it so on all transceivers? Sensitivity drops on a narrow band of IF.
  
  
  
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[Alexandr 2000]

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[santana]

• Hello everyone I want to ask if anyone has checked the sensitivity of this transceiver with different IF filters? I checked in CW mode with a 2.3kHz 50mkV filter from the generator, the S-meter shows S=9, and when the 0.5kHz filter is turned on, the same signal is determined by the S-meter as S=6. Is it a malfunction? Or is it so on all transceivers? Sensitivity drops on a narrow band of IF.
  
  

My rig had virtually nil audio output on the 500hz filter 6khz and 2.3khz were fine--cured by resoldering the connections between the filter pcb and the main pcb(both sides where the projections from the filter pcb come thru on the main pcb.

 

[Alexander]

Soldered the connection of the filters to the main board. Didn't solve the problem. Who can tell you where else to look?

 

[Chris Wilson]

I mostly use the rig for CW. While the CW filter drops the S meter reading significantly, the signal to noise ratio improves significantly. I tend to give RST reports relative to the base noise, rather than rely on the meter.
I have a Yaesu FT747GX and that knocks an S point off the signal, but again, the noise drops off significantly against the signal
Hope this helps

 

[Alexander]

Thanks for the tips!