T25-35SA Information T25-35SA Subatible Tone Decoder Information

T25-35SA Subaudible Tone Decoder

The Mueller Broadcast Design T25-35SA subaudible tone decoder provides a simple and reliable way to detect the 25 and 35 Hz control tones sent by many satellite-delivered program networks. It is entirely self-contained and only requires audio and control hookups to your satellite receiver and equipment to be controlled.

The input is balanced and bridging, with a minimum impedance of 9.2 Kohms. This input is a true differential configuration, meaning that it will not introduce noise or other unwanted signals into your satellite audio. It will work equally well with balanced and unbalanced lines.

The detection circuits are bandpass filters which have a very narrow passband. The unit will detect on frequencies which are up to 3 Hz off (assuming a minimum tone level of -10 dB from program level), but the notch efficiency will degrade severely at these extremes. Normal tone rejection at the output is at least -20 dB, with as high as -45 dB possible if the tones are exactly on frequency.

The input level is not critical. If the output is 0 dBm nominal, the circuits are in the middle of the +/- 6 dB operating window. An easily-adjusted gain control inside the box allows input levels of -15 to +10 dBm. It is set at 0 dBm input when shipped. The output is active balanced at 0 dBm (600 ohms) nominal. Unbalanced output connections are accommodated.

Repair service

We charge a flat rate repair fee of $75 plus return shipping.  Turn around is two weeks or less, often same day we receive the unit.  Please contact us for information.

Technical support is available by phone from 10 AM until 7 PM Monday - Friday (central time) at 708-352-2166. Outside these times you can leave a message and we will call you back as soon as possible, usually within 24 hours.

The T25-35SA is no longer available new but we do service existing units.