Using Doppler Direction Finders with AOR DV1 Receiver

Recently one of our customers requested that we include the AOR DV1 as a receiver option.  We are always happy to support as many receivers as possible, so we gladly agreed.  Our customer sent us a DV1 and we proceeded to add the firmware to control the frequency, squelch, and volume.  Since each receiver requires a different set of calibration constants we performed our calibration routine and entered the constants.  All appeared to be well.  However, occasionally when the receiver was powered off and then back on the bearing would shift by 180 degrees.  We traced the problem down to the fact that the phase of the DV1 audio is not constant for a given received signal.  Something in the processing of the received signal causes the phase to shift.  This issue does not make the DV1 unusable with our direction finders; however, each time the receiver is turned on the user must verify the calibration.  We have reported this issue to AOR and they have indicated to us that they are working on a fix.  When that fix becomes availalble we will release firmware that will support the DV1.

In the interim if you plan on using an AOR DV1 receiver with our direction finders, please make sure you check the calibration prior to proceeding on your direction finding journey.