Do both diplexers need to pass DC for Amplified antenna?

Oakenshld

SatelliteGuys Family
Original poster
Jan 20, 2004
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I have done some searches, but cant find a difinitive answer for this. I have a Dish 500 with 2 sw-21s. On goes to the upstairs reciever and is fine. The other I have diplexed in the attic to an antenna, then single run of RG-6 to the 811, then diplexed out again at the 811 for Sat and ANT.

I have purchases an in-line powered amplifier..

http://www.radioshack.com/product.a..._name=CTLG_003_010_001_000&product_id=15-1170

My questions are:

1) Where do I put the in-line AMP and where do I put the power inserter,if I even need to, or will the 811 power it with DC pass on the ANT side of my diplexer.

2) Do both diplexers need to pass DC through the ANT side.

Thanks for all the help.

oak
 
I don't think you can safely diplex a powered antenna.
I can think of one way to safely do it, but will wait for more knowledgeable people here to respond first.
 
Is this a powered antenna or just an inline amp? If just an inline amp.
Just make sure the low side of the diplexer (OTA side) will not pass DC.
Put the amplifier after the split near your TV.
 
You should only amplify the OTA antenna signal and not the satellite signal plus the OTA antenna. Starting from the antenna it should be- antenna, inline amp, diplexer w/ the satellite signal and antenna signal connecting into one, in through your house and then diplexed again to seperate the signals.
 
Replace the 15-1170 with a 15-2505. It will work better and you won't have to worry about the inline stuff.
 
Oakenshld,

If you don't want to use the power inserter, only one of your diplexers needs to pass DC on both ports. That would be the diplexer on the antenna end.
The flow would be: antenna, amp, dual port power pass diplexer, single cable,
regular diplexer, satellite in and antenna in on your receiver. Make sure your diplexer is after the SW-21 switch as this switch will not pass the antenna signal.
 
ats7627 said:
Oakenshld,

If you don't want to use the power inserter, only one of your diplexors needs to pass DC on both ports. That would be the diplexor on the antenna end.
The flow would be: antenna, amp, dual port power pass diplexor, single cable,
regular diplexor, satellite in and antenna in on your receiver. Make sure your diplexor is after the SW-21 switch as this switch will not pass the antenna signal.

Thanks ATS and all, that's what I needed to know. Now to find a dual DC passive diplexer.

Oak :up
 
Quote{If you don't want to use the power inserter, only one of your diplexers needs to pass DC on both ports. That would be the diplexer on the antenna end.}

Perhaps I don't understand, if you do this won't the dc voltage from the Sat receiver pass through to the antenna side and interfere with the amp on that side?
 
Unh. rcbridge is on the right track. If we're talking about Legacy LNBFs, you can NOT put a OTA antenna power inserter on any part of the line carrying satellite signals.

Plain and simple, put the power inserter between the amp and the diplexer, and make sure all your diplexers are DC Blocking.

Anything else gets real futzy.
 
SimpleSimon said:
Unh. rcbridge is on the right track. If we're talking about Legacy LNBFs, you can NOT put a OTA antenna power inserter on any part of the line carrying satellite signals.

Plain and simple, put the power inserter between the amp and the diplexer, and make sure all your diplexers are DC Blocking.

Anything else gets real futzy.

OK, That changes things a bit. I have legacy Duals. So maybe this will work better.

Antenna -> inline amp -> power inserter (I have power plug in attic) -> Diplexer (DC Block ANT side) -> single cable -> Diplexer (DC Block ANT side) -> cable from ANT on Diplexer to ANT IN on 811 AND cable from SAT on diplexer to SAT on 811.

Is this acceptable?

Thanks again for all the help.

Oak
 
SimpleSimon said:
Unh. rcbridge is on the right track. If we're talking about Legacy LNBFs, you can NOT put a OTA antenna power inserter on any part of the line carrying satellite signals.

Plain and simple, put the power inserter between the amp and the diplexer, and make sure all your diplexers are DC Blocking.

Anything else gets real futzy.

Simon,

In this situation the dual DC pass diplexer would provide power to the inline amp via the satellite receiver, therefore, no power inserter would be required. The only power on the coax comes from the receiver. JVI makes a dual DC pass diplexer specifically for powering antenna amps via the satellite receiver. I have used these on installations myself and it works great.
 
ats7627 said:
Simon,

In this situation the dual DC pass diplexer would provide power to the inline amp via the satellite receiver, therefore, no power inserter would be required. The only power on the coax comes from the receiver. JVI makes a dual DC pass diplexer specifically for powering antenna amps via the satellite receiver. I have used these on installations myself and it works great.

I guess my question would be..

Would the amplifier itself provide better (higher dB, cleaner, etc) performance if I use a dual power pass diplexer using no power inserter and let the STB power it, or would it better the way I described above, with the power inserter right at the amplifier in the attic before going through the 1st standard (non ANT side power passing) diplexer?

Or is this just a test and see?

Thanks, Oak
 
Oak,

The Radio Shack amp you are using has a very high noise figure anyway (7.5db max with UHF). I would do it which ever way is easier for you.
 
I agree that Legacy (and DishPro) can provide power to "things". But there are limits. That being said, the limit is probably high enough to run the OTA amplifier - unless the cable runs are too long.

My big question is, how does the amplifier respond to the fact that Legacy uses different voltages?

OK, concerns aside, I say Post #10 is best but it could very well be that DC-passing diplexers WILL power the amp OK.
 
SimpleSimon said:
I agree that Legacy (and DishPro) can provide power to "things". But there are limits. That being said, the limit is probably high enough to run the OTA amplifier - unless the cable runs are too long.

My big question is, how does the amplifier respond to the fact that Legacy uses different voltages?

OK, concerns aside, I say Post #10 is best but it could very well be that DC-passing diplexers WILL power the amp OK.

OK, I have hooked it up via post #10 and everything is coming in @ 85-94%. I am lucky that all my DTV locals exept one share the same tower and the other is only 2 miles from the 1st one. Got PBS, UPN, CBS, NBC, ABC, and FOX. No droppouts. Thanks for everyone's help.

Oak. :clap
 

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