Need advice with install...

[AppliedAggression]

I currently have a Dish500 and a 300 pointed at 61.5. I'm using legacy with (2) 21 switches powering 2 dp receivers. Now my new 721 should be arriving today along with a dp twin, dp single and a dp34 switch.

It makes the most since to have the dp34 switch closer to the receivers so I wouldn't have to run as much cable. Does it make any difference if the lines coming out of the LNBs go into the ground block first, or into the switch then into the grounding block?

I also wanted to make sure that dp can handle a 100' run of cable before it reaches the switch. Will this work? My only other concern is that I recently read on a site that if you're going from DishPro to legacy, you MUST run a check switch with everything unplugged before plugging up the legacy LNBs and switches, probably because of the powering of the switch/LNB. Is there anything I should know before removing the old LNBs and installing the new ones?

 

[Mr Tony]

I currently have a Dish500 and a 300 pointed at 61.5. I'm using legacy with (2) 21 switches powering 2 dp receivers. Now my new 721 should be arriving today along with a dp twin, dp single and a dp34 switch.

It makes the most since to have the dp34 switch closer to the receivers so I wouldn't have to run as much cable. Does it make any difference if the lines coming out of the LNBs go into the ground block first, or into the switch then into the grounding block?

LNB to ground block to the DP34

I also wanted to make sure that dp can handle a 100' run of cable before it reaches the switch. Will this work? My only other concern is that I recently read on a site that if you're going from DishPro to legacy, you MUST run a check switch with everything unplugged before plugging up the legacy LNBs and switches, probably because of the powering of the switch/LNB. Is there anything I should know before removing the old LNBs and installing the new ones?

DishPro will allow up to a 200' run...so 100 wouldnt be a problem.
if you are going from Legacy to DP, unhook the line to the receiver and run a check switch to clear the memory. Then you should be OK

 

[Grandude]

I am quite sure that the ground block will be redundant in your case. The DP34 Switch
has a place to attach the ground wire.
Also it seems that I read somewhere that putting the DP34 closer to the receivers is better. Don't know why but the reduction of the number of cables is a good idea.

 

[JohnDoe#2]

Your hook-up scheme should be fine. But you may want to replace the ground block if you can't verify that the old one is rated for DP (~2.5Mhz).

Actually, when converting from legacy to DishPro it isn't necessary to "clear the matrix" with a switch test. But when converting from DP back to legacy it certainly is necessary to prevent the higher DP control voltage from damaging the legacy LNBFs.

 

[SimpleSimon]

I saw a DishPro cable length table somewhere (sorry, can't think of where right now). There ARE some significant limits depending on where the switch lives in relation to the other boxes. Sorry, but all I can remember is that it was NOT symmetrical, and at one end of the table it got down to 10' from the dish became max for the switch.

Just a heads up - I'll try and find it after I check some more posts.

UPDATE. My bad. It was a Legacy chart at http://ekb.dbstalk.com/181
Nothing to do with DishPro.

 

[Grandude]

I saw a DishPro cable length table somewhere (sorry, can't think of where right now). There ARE some significant limits depending on where the switch lives in relation to the other boxes.

I finally found where I read it. In the DP34 Multidish Switch Installation Guide it states on page 6 that you can have up to 200 feet of cable between a DishPro
LNBF and a DishPro satellite receiver with the DB34 Switch connected at any point along the 200 feet of cable. The cable must be rated for 950 to 2150 MHz.
Item 4 on page 8 states "The switch takes the place of a ground block." My note: This of course only applies if the switch is installed at a location convenient to tying into the existing building ground.
To me this would mean the best place to install the switch is at the point of entry into the house, close to the building ground when using it in lieu of a ground block. If mounting the switch inside somewhere, it would be a good idea to install a ground block at the entrance of the cable into the house.

 

[SimpleSimon]

Good stuff - thanks! And in case my post update got missed - the table I found was NOT for DishPro, so not relevant.

I agree with your recommendation - mount the switch at the cable entry point and ground it well - I mean correctly, not just to a garden hose faucet or something.