how to connect sd dvr and 3 additional recievers

You need to add one of these http://www.solidsignal.com/pview.asp?p=WB68&d=Zinwell-WB68-DIRECTV-Approved-Wide-Band-Frequency-(Ku%2FKa)-6x8-Multiswitch-(WB68)

Run the four lines from the Dish into the 6x8 inputs then rune dedicated RG6 to each  receiver from the 6 x8 outputs.

Note that a 2x4 would not work.  Any multiswitch must have at least the same number of inputs as the dish has outputs, in this case four.  The 6x8 Zinwell is a good choice, use the first four inputs on the left end of the six inputs.

I checked the Fresno DMA data, and you need to see the 119 satellite in order to receive SD locals, so gl1800 and dcd are correct in their advice.  Using the 2x4 switch would lose all your locals, because you would only receive the 101 satellite. But, just for completeness, if you were a customer using the 18x20 phase III oval dish and did NOT need 119 (because you were in an area where your SD locals were on 101, and you did not need the ethnic package or the handful of other channels on 119) you could use the 2x4. Essentially this would make your dish appear to the receiver as if it weree an 18in round dish.

Tex,  That's interesting, I was actually unaware of that choice.  If you would, can you expand a bit?  Would the user (in the hypothetical case) connect two of the four dish feeds to the 2x4 and use the other two dish feeds to go directly to the receivers?  Essentially providing six feeds?  And then the feeds from the multiswitch would drop the 110 and 119 signals but I assume the two direct feeds would still appear as a 3 LNB dish?

I assume that my statement that "Any multiswitch must have at least the same number of inputs as the dish has outputs" is true if you wish to perfectly mirror the dish output  to the multiswitch output?

Yes, if you connect two cables from the oval dish dish (any ports) to the 2 connections on the multiswitch, and then tell the receivers attached to the multiswitch that they are connected to an 18in round dish, then they will act as if they are.  The two other outputs from the dish can be individually connected to additional SD receivers, and those receivers can access all the satellites on the phase III, not just 101.  You've thought it through correctly.

Yes, your statement is correct if you want to access all the capabilities of the dish through the multiswitch, which most of the time people do.

From time to time we see posts where DirecTv installers have created one of these "hybrid" systems, and they can be difficult to understand (and debug) so they are best avoided!  People should follow your "rule" unless they really know what they are doing!

AND just for more information, BUT not for normal use, you can also take two of the four and feed a 2x4 and then take the other two and feed a second 2x4 and then tell all recievers that they are on the 18" with mulitswitch. This gives you a total of 8 recievers.    A cleaner way is to use a 4x8 or 4x16

This system must be ALL SD recievers. Not a recommanded intall, but it does work.

Thanks much guys, I'll retire a wiser man tonight due to your treatise.