When DirecTV came out with their SWM (Single Wire Multiswitch) dish they created both a boon and a bomb for RVers.  The new dish was a boon in that it brought all satellite feeds from the LNB into the RV on one cable.  From there it was relatively easy to distribute the signal to multiple receivers using their splitter box (see photo below) 

The bomb was the difficulty in setting up the dish on the road.  It requires a 21 volt power supply which is not compatible with most of the satellite finders RVers use. There are some new model finders out there designed for the SWM but they tend to be pricey ($200+).   The SWM dish also requires the user to keep the receiver powered off when aligning the LNB if they are using a satellite finder to tune in the LNB.

We here at TV4RV never gave much thought to these problems until we came upon this thread in the RV.Net forum pages.  The discussions in this thread go on for 9 pages as we write this, so we can only assume this is a BIG issue.  There is a lot of helpful advice in this thread and we encourage you to read it through if you have or are thinking of using a SWM dish.

From what we understand from reading through this thread and from other on-line sources there seems to be a fairly easy and relatively inexpensive solution for those users who prefer using the satellite finder setup method over the "2 person" setup method.  DirecTV has a part called "SWM ODU Alignment Signal Locator ASL-1".  This device allows you to pass power from the power supply to the LNB which then sends signals from satellites 101 and 119 to two individual outputs.  In addition it steps down the 21 volt dc power from the power supply to 18 volts dc at another output terminal that can be used to power a satellite finder.  See below for options.

Once the signals have been located and fine-tuned for maximum strength the ASL-1 and finder can be removed and the power cable can be connected directly to the LNB.  At this point the receiver can be powered up to verify that setup has been completed.