Do Diplexer’s denigrate signal quality in any way?

[golfgame]

Here is my issue. I previously used a Samsung TS360 HD receiver with no issues. I changed to a HR10-250 for the Tivo features. While using the Samsung I received all of the OTA HD channels from Detroit. After making the change to the HR10-250 I had some issues in reception which turned out to be a cabling issue.

I have a 3 LNB dish with (2) leads coming in. One went to the Samsung and one went to another Sony receiver that services the rest of the house for the non-HD feeds. In addition there is (1) lead coming in from the OTA antenna that went directly to the Samsung OTA IN jack. Picture was great.

DTV sent out a tech to see what was up with the HR10-250. Because that receiver requires (2) leads from the dish his solution was to install a “Perfect Vision PVDP3 Diplexer" out at the Dish and fed the OTA lead and (1) of the Sat leads thru it. The remaining lead from the Dish was left hooked up to the Sony receiver.

That setup works with the exception that I am now not receiving the Fox HD OTA channel. DTV’s answer is to install an in line Amp to boost the signal. I have not tried that yet.

From my location in Rochester, MI all of the channels that come from Detroit are from 199* - 223* on the compass and range in distance from 15.8 miles to 17.7 miles. NBC is at 207* and 15.8 miles. The problem Fox channel is at 207* and 17.7 miles.

Only once have I had reception on the Fox HD channel.

I know this is a rambling post but I would really like to receive the Fox HD signal. Does anyone have any input on this issue?

Thanks,

[maharg18]

Yes diplexors can slightly degrade the signal. The solution would be either run another cable from the antenna to the HD Tivo just for the antenna, or install a pre-amp which should help.

[golfgame]

Yes diplexors can slightly degrade the signal. The solution would be either run another cable from the antenna to the HD Tivo just for the antenna, or install a pre-amp which should help.

What is a Pre-Amp?

What do they do?

How much are they?

Where do you get them?

:)

[Proc]

Get rid of the diplexer and run the coax straight from your OTA antenna to the receiver. I had an H10 receiver that got nothing (I am also in Detroit) via OTA. When I removed the diplexer, it dramatically improved (especially Channel 7 which was the worst and still is for me to get in next to Channel 50-UPN). I've since upgraded to the H20 (the H20-600 LG made-model) which has an excellent OTA tuner. Its much better than the one in the H10 and the HR10-250. The new D* DVR should use a much-improved OTA receiver. However, it will be MPEG4, which will allow you to get the Detroit locals in via the receiver if you upgrade to the AT9/5LNB dish.

[golfgame]

Get rid of the diplexer and run the coax straight from your OTA antenna to the receiver. I had an H10 receiver that got nothing (I am also in Detroit) via OTA. When I removed the diplexer, it dramatically improved (especially Channel 7 which was the worst and still is for me to get in next to Channel 50-UPN). I've since upgraded to the H20 (the H20-600 LG made-model) which has an excellent OTA tuner. Its much better than the one in the H10 and the HR10-250. The new D* DVR should use a much-improved OTA receiver. However, it will be MPEG4, which will allow you to get the Detroit locals in via the receiver if you upgrade to the AT9/5LNB dish.
The way I understand it you need two leads to be able to record 2 channels at once. With only one lead available from the dish with out the diplexer you would only have one lead. The diplexer is providing the second lead in a sense. Could a third lead be run from the dish? Because it has 3 LNB's does that mean 3 leads are available? Remember I am using the current second lead to feed the oldr Sony receiver.
:confused:

[JimSpence]

The 3 LNB dish has four outputs. All four are capable of delivering all programming from the various satellites. So if all you need is two lines, for the HR10-250, you are okay. But, yhou need at least three. I will also recommend that you have a dedicated line run from the OTA antenna to connect to the HR. At the time that this coax is run, you might as well run the other two from the 3 LNB dish.

One note, not all OTA receivers have the same sensitivity. Obviously, the HR10 doesn't do as well as your Samsung.

[golfgame]

The 3 LNB dish has four outputs. All four are capable of delivering all programming from the various satellites. So if all you need is two lines, for the HR10-250, you are okay. But, yhou need at least three. I will also recommend that you have a dedicated line run from the OTA antenna to connect to the HR. At the time that this coax is run, you might as well run the other two from the 3 LNB dish.

One note, not all OTA receivers have the same sensitivity. Obviously, the HR10 doesn't do as well as your Samsung.

Jim,

Thanks for your response. Would you speculate that running the single direct lead from the OTA antenna might solve the inability of getting the Fox HD channel?

If I understand you right I could get the one lead for the older Sony and the two leads for the HR10-250 and still have one free?

Can you shed any light on the previous mention of using a Pre-Amp in this post? I don't know what those are.

[JimSpence]

Using a diplexer could reduce the signal just enough for your Fox OTA so that the receiver can't lock on. A pre-amp is a unit that is connected at the top of the antenna to amplify the signal. This is done so that you don't amplify any noise on the line after it enters the house. There is a power supply inside the house on the line to power the pre-amp. A separate line may be all you need.

Have you checked the signal strengths for your OTA channels?

[golfgame]

Using a diplexer could reduce the signal just enough for your Fox OTA so that the receiver can't lock on. A pre-amp is a unit that is connected at the top of the antenna to amplify the signal. This is done so that you don't amplify any noise on the line after it enters the house. There is a power supply inside the house on the line to power the pre-amp. A separate line may be all you need.

Have you checked the signal strengths for your OTA channels?
Here are the results of checking the signal strengths.

Sat In #1=100 Sat In#2=100
OTA In #1=0 OTA In=22

The signal strength on all of the OTA Digital channels are above 80 with the exception of 2-1 in Detroit which is Fox. That reports no digital signal.

[JimSpence]

You need to check the signal strengths for all transponders on all satellites to see if you have any anomalies. With the 100 you mention, it was probably a spot beam.
You said "OTA In #1=0 OTA In=22" and then 80 except for 2-1. Exactly what are checking in the first case?

[golfgame]

You need to check the signal strengths for all transponders on all satellites to see if you have any anomalies. With the 100 you mention, it was probably a spot beam.
You said "OTA In #1=0 OTA In=22" and then 80 except for 2-1. Exactly what are checking in the first case?
The first test I did the following

Messages & Setup
System Test
Sat#1=100
Sat #2=100
Ant In #1=0
Ant In #2=22

The second test

Messages & Setup
Settings
Sat & Off Air Antenna
Test Off Air Signal Strength
Most channels wre in the 80 plus range except the Fox HD