Technical Bulletin



The TX-37 is equipped with a 400 Hz test tone that is used to test the transmitter and to aid in the tuning of receivers. We have had some complaints, even though the test tone is disengaged, of the test tone bleeding into the transmission and being apparent at the receivers. Even though the level of this tone cross-talk was quite low, a change was required to insure an acceptable level of performance.

On 12-18-1995 an Engineering Change (EC) addressing this issue was released to manufacturing. This modification requires the circuit board being removed from the chassis, cutting two traces on the back side of the board and soldering a jumper wire between two solder pads. TX-37's with this EC will not demonstrate any test tone cross-talk.

If you are aware of any product that was shipped before this date and have complaints of the test tone bleeding through, please contact Technical Support at 1-800-945-7730.
Technical Support will arrange to perform the modification at the factory or provide you with a copy of the EC.