AVS Forum banner
1 - 8 of 8 Posts

·
Registered
Joined
·
6 Posts
Discussion Starter · #1 ·
I've tried searching through the forums to the best of my ability and have come to a dead-end.


Here's my situation... I recently rewired my whole house with RG6 quad shield coax- replacing the old deteriorating RG59 the builders had run 14 years ago. I also upgraded the 14 year old, corroding signal splitter located on the side of my house to a new 5MHz-2.4GHz signal splitter. The main reason for all of this-- lots of spare time, modernization/upgrading, and I upgraded from basic cable to Comcast digital HD.


As I was replacing the splitter I noticed that a high pass filter was installed on the main line going into the splitter. Comcast must have put it there 14 years ago when the cable was initially installed. I did not put the high pass filter back onto the splitter. I've had no noticeable issues with quality or interference since doing so.


Here's a picture of a similar HPF I found on the net: http://i47.tinypic.com/2mi42lg.jpg


My filter's identifying marks are "EZHP-50" which is High Pass, 50-1000MHz.


So, here's my question... Does the high pass filter need to be reinstalled?


Thanks.


And if you're wondering... no, I don't have cable internet.
 

·
Registered
Joined
·
3,993 Posts
A 50 MHz Highpass filter might have been installed by the cable company to better protect their system from interference that your residence might otherwise inject into the line, but in my experience, the only time I have encountered that filter was in applications where it was used to support the use of a bootleg cable box. Chances are the decryption system that such a filter supports is no longer in use.
 

·
Registered
Joined
·
6 Posts
Discussion Starter · #3 ·
Interesting. I'm the first and only resident of this home and I can say with 100% certainty that no bootleg cable box, or any other tuner (besides one built into tv sets) has ever been used in my home. That is, until I upgraded to digital HD. I now have a RNG110 from Comcast. Thanks for the info, AntAltMike.
 

·
Registered
LG 55" C9 OLED, Yamaha RX-A660, Monoprice 5.1.2 Speakers, WMC HTPC, TiVo Bolt, X1
Joined
·
45,723 Posts

Quote:
Originally Posted by b3165243 /forum/post/18236629



My filter's identifying marks are "EZHP-50" which is High Pass, 50-1000MHz.


So, here's my question... Does the high pass filter need to be reinstalled?

Nope.
 

·
Registered
Joined
·
2 Posts
It was likely installed for a problem that no longer exists. It is designed to block signals in the return band from getting back into the cable plant. You upgraded your cable lines which was probably the main source of the problem in the past. It could have been many other things, but it's possible a tech noticed a problem and didnt bother to track it down and instead put that filter back on. If it was a problem with a VCR or TV you might still be putting noise back into the system. The only way to tell is with a meter. If you have one check it out, otherwise put it back on. It's not going to hurt anything to leave it on there unless the filter is bad of course.
 

·
Premium Member
Joined
·
6,261 Posts

Quote:
Originally Posted by madcap3k /forum/post/18239425


It's not going to hurt anything to leave it on there unless the filter is bad of course.

Putting it back on will kill the return signal from the new cable box. That will lead to problems with an interactive features such as On Demand or PPV and could cause the box to stop working all together.
 

·
Registered
Joined
·
6 Posts
Discussion Starter · #7 ·

Quote:
Originally Posted by madcap3k /forum/post/18239425


If it was a problem with a VCR or TV you might still be putting noise back into the system.

Now that I think about it, it may have been an old tv that died due to a power supply problem which affected the tuner. It has since been disposed of.

Quote:
Originally Posted by homcom /forum/post/18239592


Putting it back on will kill the return signal from the new cable box. That will lead to problems with an interactive features such as On Demand or PPV and could cause the box to stop working all together.

That is exactly why I didn't put the HPF back on. I figured it would do nothing but harm.



Just for 'fun', I screwed the HPF onto the coax going into the cable box, then went into the diagnostics menu and checked the s/n ratio and signal levels- there was no difference in the levels, with or without the HPF.


SNR 22.4

sig. level dBmV -5.5 @ 75250 kHz

Ib1 -0.6 @ 356990 kHz


I did notice though that IB1 tuner errors fluctuates between good to fair. not sure what that means, but it's always been that way.
 
1 - 8 of 8 Posts
Top