Funkwerk 25kHz/8.33kHz radio
 

If 8.33kHz is set during setup, will it receive a 25kHz transmission?
I have come to the conclusion that it will not always receive.( sleeping receiver syndrome)
My tests seem to indicate that it is slightly off frequency, sometimes received and sometimes
not, the transmission always received by atc. Maybe a wider band receiver?
When set to 25kHz there is no problem, is this the required setting for the U.K?

This used to happen on the Bae146 when 8.33 radios were first installed.

Any thoughts from the radio enginners please.

There is a note about needing to set the desired frequency 5 kHz higher for a 25 kHz chanel when using an 8.33 kHz channel spacing in the Operation and Instruction manual at Funkwerk Avionics USA - compact aircraft radios and transponders. This is mentioned in section 2.5.1 (for the ATR833-LCD). See if this makes any difference.

Thank you very much EEngr. That explains the problem perfectly.
When this topic was discussed, I had no access to the radio manua,l thanks a million for the link.
There is a article in the May 13 Light Aviation magazine regarding this, but no mention of the "fudge"
required when 8.33 is selected.