# OTA Reception Issues



## odubman (Feb 5, 2003)

I'm recently having some OTA reception issues that I don't really understand. I'll try to keep this as short and to the point as possible. I live in Fairfax, VA and my local stations (Washington DC) are ~17 miles away and in the same direction according to AntennaWeb. My previous setup (as of a week ago) was working pretty well. I had a CM 4221 antenna (installed in the attic) with a Wineguard AP-4800 amp connected to a Samsung SIR-T151 HD receiver. I was able to successfully watch all local OTA channels (ABC, FOX, CBS, NBC, and a few others).

Now the issues begin.... I got a new DISH 921 receiver this week, which has its own OTA HD tuner. Using the same antenna in the attic and amp with this receiver, I was initially only able to watch NBC and FOX via OTA. To see if the new DISH receiver was causing issues, I re-connected up the Samsung OTA receiver. The issues still remained (couldn't get ABC or CBS) so I don't think the DISH receiver is the problem.

Another interesting note is that my neigbor (townhouse right beside me) has a RCA ANT3020x antenna (58" boom length with 40 mile range) in his attic (which is only about 20 feet from my antenna). He hasn't had any issues getting reception. His TV has an internal tuner for HD OTA. So, I was going to try the same antenna he has, but was only able to find the RCA ANT3022 (46" boom length), which is similar, but not quite as big. After connecting it up with same amp into DISH receiver, I had the same issues as CM 4221 setup with approximately the same signal strength for the working stations. I may still try the larger antenna, but not sure that will solve the problem.

I re-connected everything back as was (CM 4221 antenna with amp) to the DISH receiver. Now, I'm able to receive ABC OTA (in addition to NBC and FOX), but still having issues with CBS. Nothing has changed in the setup from the past few days, but now I'm able to get ABC although it occasionally bounces to 0 and freezes up. At this point, I'm pretty frustrated with things.

For those with the DISH 921 receiver, below is what I'm currently seeing regarding signal strength (scale goes up to 125) on the local OTA DTV channels:

- WTTG (FOX): Locked and Acquired --> ~90
- WRC (NBC): Locked and Acquired --> ~100
- WJLA (ABC): Locked (sometimes Acquired, but not always) --> ~80
*** until today, I was seeing Locked and Not Locked, but never Acquired with signal bouncing between 0 <--> 70 ... still bouncing to 0 every now and then
- WUSA (CBS): Locked, but not Acquired .... signal is bouncing between 0 <--> 70 (sometimes picture comes in, but freezes and disappears)

I have tried both the manual and auto DTV channel scan of the local channels. CBS is sometimes captured in scan, but I'm never able to watch due to signal strength bouncing I assume. This may be due to multi-path issues (???), but why wouldn't I have this issue with the other stations?

Sorry for the long post, but wanted to explain my situation as best I could. I'm not sure what else I can try to get CBS (and possibly ABC if it goes back out). I know most would recommend putting antenna outside (although I've had success with my current attic configuration), but this isn't a very easy option for me at this point. Any advice or thoughts on what may be causing this problem of not being able to receive CBS (and ABC until today, which is still occasionally bouncing to 0) would be greatly appreciated.


----------



## boylehome (Jul 16, 2004)

Is your neighbor using a 921 to receive OTA digital channels? There are some things that keep the 921 from acquiring the digital channels. It seems that the 921 needs to see a signal strength of around 70 or more to work effectively. Also, if you are like 20 feet from your neighbors antenna, you may be in a problem zone as compared to the neighbor. You may also experience more multipath with an antenna in the attic. My model 6000 has no problem bringing in the digital channels but the 921 needs additional digital information in the signal to let the channel actually work.


----------



## odubman (Feb 5, 2003)

No, my neighbor is not using a 921, but has an internal OTA tuner in his tv. I understand what you're saying about the 921 needing a certain signal strength. However, these problem stations are also causing issues with my original STB OTA receiver, which was working fine for many months. My only thought is that the problem is related to the signal strength bouncing from 0 to about 80 and some values in between. Is this a result of mulitpath? If so, this wasn't an issue in the past since nothing has really changed in my setup. What would cause multipath to become an issue all of a sudden? 

Is it worth trying a large 58" boom (RCA ANT3020x) antenna in the attic since my neighbor seems to have no issues with that in his attic (granted, he doesn't have a 921)? Maybe that antenna has a greater range than what I'm currently using, although I assume this wouldn't get rid of any multipath issues if that is my actual problem.


----------



## JM Anthony (Nov 16, 2003)

If it were me, I'd find a way to get out of the attic. Blonder Tongue makes a very nice, compact antenna. It's a UHF only with a stock number of 4875. My better half likes it because it's very unobtrusive. Check it out at: www.blondertongue.com/Reception

I had a Sam. 151 before I got my 921 and I get MUCH better reception with the 921. Good luck!


----------



## 4HiMarks (Jan 21, 2004)

If you are now having the same reception problems with your old equipment that used to work perfectly, it sounds to me like a connection has come loose somewhere. When I first got my 921 (one year ago tomorrow!) we had a horrible time getting a lock on one of the sat tuners. It turned out to be caused by the barrel connector in the wall plate. I have also had some problems with the cable ends disintegrating at the grounding block.
Recheck and tighten *all* connections.

-Chris


----------



## odubman (Feb 5, 2003)

Yes, I am having the same issues with the older STB, but I'm able to receive many stations just fine. I'm having issues with two of them so I don't think anything is a loose connection somewhere or I would have issues with all stations, not just a few. I'll do a quick check just to make sure, but I'm thinking I have some type of multipath issues since the signal is bouncing between 0 <--> 80 for the two problem stations.


----------



## pculley (Dec 23, 2003)

odubman said:


> No, my neighbor is not using a 921, but has an internal OTA tuner in his tv. I understand what you're saying about the 921 needing a certain signal strength. However, these problem stations are also causing issues with my original STB OTA receiver, which was working fine for many months. My only thought is that the problem is related to the signal strength bouncing from 0 to about 80 and some values in between. Is this a result of mulitpath? If so, this wasn't an issue in the past since nothing has really changed in my setup. What would cause multipath to become an issue all of a sudden?


A bouncing signal strength is often a sign of multipath; any change in the landscape between you and the tower could be causing it (new building, road sign, swaying trees etc.). Attic antennas are more likely to have problems like this as well; the height is lower, and sometimes reflections occur off of foil backed roof underlayment, or even zinc shingle granules. I'd try a different, higher location for the antenna.


----------



## odubman (Feb 5, 2003)

Guess something new in the line-of-sight could be causing this problem.... since nothing has changed in my attic or house since things were working well for these stations. I may try moving the antenna around in the attic or may have to investigate moving it outside to the roof if possible.


----------



## odubman (Feb 5, 2003)

Well... I think I've found the problem causing reception issues for the two local stations listed above. After much troubleshooting tonight, it appears the Wineguard AP-4800 pre-amp is the culprit. Once I started looking at each connection in the path between the receiver and the antenna, it appears the coax at the power supply connector going towards the pre-amp was black and somewhat burned out. I'm not sure what would cause this failure on the pre-amp, but I assume this was causing some type of improper shielding or interference causing the signal strength to bounce for these two stations. I ran another coax from the antenna to the receiver without the preamp and received all locals with decent signal strength.

I still don't understand how this problem didn't cause reception issues for most stations but did for two..... anyone have thoughts on this?

Do I really even need a preamp for my setup (using DISH 921 receiver) if most stations have a signal strength around 80 with a few others around 100?


----------



## paulcdavis (Jan 22, 2004)

odubman said:


> Do I really even need a preamp for my setup (using DISH 921 receiver) if most stations have a signal strength around 80 with a few others around 100?


Antenna mounted Preamps only compensate for the signal loss from a long coax between the antenna and the 921. All preamps add some noise to the line, so a pre-amp with a coax cable length of less than 100 ft will often result in a poorer signal. Without multipath problems, the 921 seems to stay locked on signals in the 80 - 100 range OK. A stable 80 is better than a signal that bounces from 90 to 110 in my experience.


----------



## 4HiMarks (Jan 21, 2004)

odubman said:


> Once I started looking at each connection in the path between the receiver and the antenna, it appears the coax at the power supply connector going towards the pre-amp was black and somewhat burned out.


Yep. Just as I suspected. It happened to me twice. Somehow, water got into the connection at the grounding block. Don't exactly recall what stations I wasn't getting, but I think it could only see one satellite (this was before I got my 921).

-Chris


----------



## axel0720 (Dec 19, 2004)

I am using a 360 antenna from Radio Shack , believe they only make one style , I live in Peoria Illinois and yesterday FOX came on line with there Digital Transmission (getting ready for Super Bowl ) I am getting about a 75 on the reception scale cause the sending antenna is about 35 miles away. I also am pulling in Davenport Iowa and Springfield Illinois.
Just thought I would share the type of antenna that works very well for me.


----------



## Tomos (Jan 16, 2005)

I have read many knowledgeable folks here write that in the world of the all mighty antenna, bigger is everything, so if your signal is low don't bother with an amp. I have always had a great signal on my rooftop Channelmaster 3020. Now with the 921 I can see it is around 110 to 120 no matter the weather. I am easily 45 to 50 miles from the towers. Now when I try to peek through the tiny holes in the forest I can get stations out of New York and I am 45 to 50 miles west of Philly, but when the wind blows it comes and goes.


----------

