IFD540/440 VHF Weak Tx or Rx

If the VHF seems to operate fine on start-up, but gradually get worse over time, it may be a sign that the IFD has inadequate cooling.  You can always download the logs from the IFD in question and email them to [email protected], along with a brief synopsis.  If internal temperatures exceed programmed thresholds, the VHF will start to dial back the RF to save the VHF from overheating.  

If the VHF seems to constantly be weaker than expected, our first recommendation is to have a qualified service facility perform a VSWR test on the antenna in question.  Per the IFD installation documentation VSWR should be no greater than 2.0:1 at a given frequency.

                          GOOD                                                                               

                  BAD