Cascading DP34s

[AntAltMike]

Last year I installed a DP34 trunkline system that placed four DP34s in series with one another with no problems. The antenna signals travel about 150-200 feet to a single junction closet, where each of the three LNB lines is amplified by a Channel Master 5116 inline amplifier before entering the first DP-34, and then the individual receiver coaxes run 100 to 200 feet to each receiver.

There are presently 13 receivers all on this same floor (3rd floor of an eight story building) connected to these four DP-34s. The customer (a University) now wants me to expand the system by five receivers. Four will be on the same floor as the other thirteen, and one will be on the fifth floor.

I am not a DISH dealer and haven't analyzed the DP34s. I assume that a slight amount of amplification takes place on the through signal path, so if I continue to string them together, then the Third Order Intermodulation Distortion, which goes up by 6dBc for every doubling of the amplifiers in a balanced cascade, will eventually reach an unacceptable level (-40dBc is the recommended maximum permissible 3rd order IMD level).

My inclination is to put one DP34 on the fifth floor, and to split the signal in the third floor junction closet so that there are parallel cascades of three and two DP34s there.

I might also source the fifth floor DP34 with high frequency splitters so that its through amplifiers are not part of the intermodulation equation affecting the third floor outputs. In such an arrangement, I would keep the Channel Master inline amps where they are, on the third floor.

Should I use splitters that are power-blocked on one leg, or splitters that pass power on both legs but are diode steered? Or is there some other standard architecture that DISH commercial installers use in large systems?There is no danger of ever losing my LNB powering due to receivers being unplugged.

 

[SimpleSimon]

You're just lucky that the fourth DP34 is working at all. You're definitely over the limit (200 feet) for distance on those feeds.

If you still want to try, E* has DP Splitters. They are power-blocked on one side.

The best solution from the hardware perspective is to hang another dish, or swap out the DP Twin (assuming) for a pair of DP Duals. This gives you more native feeds.

 

[boba]

He could also use a DP Quad with three DP-34s off each pair of outputs. Three DP 34s are the maximum DISH recommends daisy chained.

 

[40_oz]

He said each of the 3 LNB lines, so I am assuming he is using a superdish..in which case i am even more surprised that a 4th switch would work without issues at that distance.
We've done quite a few retirement homes/apartment complexes and usually just hung a new dish for every 12 customers. If keeping them plugged in is not an issue, you could also go to a 44 switch and the dp+ splitters that are now included with dual tuners. which would effectively double the amount you can run off 1 SD.
Of course it may be more cost/time effective just to throw up another SD unless you have the 44/splitters layin aroun.