User's Manual

The upconverter is adjusted to provide the downstream Intermediate Frequency (IF) signal at
the center frequency appropriate for the transmit module within the Hub Transceiver to create
the desired RF carrier frequency. See Table in the Antenna and Frequency Planning section of
this manual for more information. The output of the upconverter is connected with RG-6 cables
through a 12 dB tap, and thence through the lightning protector to the cable to the Hub
Transceiver.
The 12 dB taps provide less than 1 dB of attenuation to the signal passing through and “copy” of
the signal 12 dB lower in level to the tap port. These are utilized for inserting a spectrum
analyzer for system set-up and maintenance without disturbing the normal cable connections.
5.3.4 Splitters, Pads and Taps
There are many vendors that make splitters, pads (attenuators) and taps for the Cable TV
industry. Channel Vision is one vendor (www.channelvision.com), and photos of the items are
in Figure 5-22. The splitter shown is 2:1, which is the most commonly used in the ARCell
applications. It is important to select parts specified to 1 GHz, in contrast to the 900 MHz parts
sold in grocery stores.
The Channel Vision 2:1 model #HS-2 has an insertion loss of 3.5 dB and is under $4.
The Channel Vision 12 dB tap model #TP12dB has an insertion loss of less than 1 dB and is
under $7. Pay careful attention to the port labels. The main signal is attached to the “IN” port,
the “TAP OUT” port is the signal attenuated by 12 dB, and the “OUT” port is the main signal with
almost no attenuation.
The Channel Vision 10 dB pad model #3000-10 is under $2.
Regardless of the brand, the tap and splitter have the same shape, so take care to connect the
cables to the proper port on the proper unit.
The splitter is officially a splitter/combiner, but it is not used as a combiner in these examples.
Splitter
Tap
Pad
June 2003 Page 5-12