L-band Questionnaire

One of the goals of the Earth Terminal Refurbishment Project (ETRP) is to ensure that an L-band signal is available in the same rack in which a station's demodulators are located or in an immediately adjacent rack.

The following questions are designed to ascertain your station's current Inter-Facility-Link (IFL).

1) Which manufacturer's downconverters are currently in use for the station's downlink?

1. Typical C-band downconverter manufacturers include: Rockwell/Collins, Scientific Atlanta, Microdyne, Microphase.
2. The only L-band downconverter that we have distributed to (and are aware of being used by) PRSS stations is the Satellite Systems Corporation Model 4421 (or 4420 for a very few early users).

If the answer to question #1 is (a), then a complete conversion of the station's IFL to L-band will need to be performed. Regardless of the answer to question #1, we still need to ascertain the location of the station's downconverters, and determine whether L-band or 70 MHz signals are actually being delivered to the ABR-700 demodulator rack.

2) Where are the station's downconverters located?

1. In an equipment enclosure outdoors at the antenna site
2. In a different building than where the demods are located
3. In the same building in which the demods are located, but in another room
4. In the same room in which the demods are located
1. In the same rack as the demods
2. In a rack adjacent (same row) to the demod rack
3. In a rack not adjacent to the demod rack

If the answer to question #2 is either (a), (b), or (c), then additional work will be required by the project to assure the availability of an L-band signal in your station's demodulator rack. This prompts question #3:

3) What is the distance from the location of the downconverters to the demod rack?

In order for a station to be considered L-Band-ready by the ETRP, an extension to the current IFL will be needed to bring the downconverters into the station's demodulator rack. In these instances, a site visit by an ETRP representative may be required to develop a detailed statement of work for the IFL conversion.

L-band conversion kits consist of a Phase Locked Loop Low Noise Block Converter (PLL-LNB), two SSC 4421 downconverters, a 4-way L-band splitter, and three short F to F jumpers. These kits were shipped to a number of stations that indicated they might be able to make the L-band conversion themselves. Two years later, we are finding that many of these stations require assistance to perform the L-band conversion. If your station is still using C-band downconverters, please see question #4.

4) Can the L-band conversion kit that was shipped to your station be located?

If so, this kit will need to be installed in the racks adjacent to the demodulators by a qualified technician or an ETRP representative.

For more information about L-band conversion, please refer to the L-Band Conversion FAQ.