Problems with one channel

[RandallA]

Ok, here is my new setup:

Antenna CM 4220 in the attic going into a 2 way splitter.
One leg goes to a 722 Dish Network receiver. (Diplexed about 75 ft.)
The other one goes to a 622 E* receiver. (Diplexed about 30 ft.)
Both runs with RG6 Quad.

These are the channels I get from Antennaweb.org

* yellow - uhf KTVU-DT 2.1 FOX OAKLAND CA 346° 6.3 56
* yellow - uhf KSTS-DT 48.1 TEL SAN JOSE CA 94° 33.9 49
* yellow - uhf KTEH-DT 54.1 PBS SAN JOSE CA 95° 34.4 50
* yellow - uhf KDTV-DT 14.1 UNI SAN FRANCISCO CA 94° 33.9 51
* yellow - uhf KICU-DT 36.1 IND SAN JOSE CA 96° 34.3 52
* yellow - uhf KKPX-DT 65.1 ION SAN JOSE CA 19° 2.0 41
* yellow - uhf KBCW-DT 44.1 CW SAN FRANCISCO CA 346° 6.3 45
* yellow - uhf KCSM-DT 43.1 PBS SAN MATEO CA 346° 6.3 43
* yellow - uhf KGO-DT 7.1 ABC SAN FRANCISCO CA 346° 6.3 24
* yellow - uhf KTSF-DT 26.1 IND SAN FRANCISCO CA 19° 2.0 27
* yellow - uhf KMTP-DT 33.1 IND SAN FRANCISCO CA 346° 6.3 33
* yellow - uhf KRON-DT 4.1 MNT SAN FRANCISCO CA 346° 6.3 57
* yellow - uhf KCNS-DT 38.1 SAH SAN FRANCISCO CA 346° 6.3 39
* yellow - vhf KNTV-DT 11.1 NBC SAN JOSE CA 20° 1.9 12
* yellow - uhf KQED-DT 9.1 PBS SAN FRANCISCO CA 346° 6.3 30

I get most of the channels at 100 (very close to the transmitters) and I get the same readings on both receivers except for channel 4.1 on frequency 57. On the 622 I get 68, on the 722 I get 78 and I can't figure out why the 10 pts. drop on the 622.

This is what I've done,

Replaced diplexers
Replaced splitter (3 different ones)
Replaced all jumpers going to the 622 but not the cable going from the attic to the wall in the master bedroom.
Tried different attenuators (6db, 3db).

If I skip the splitter, I get 78 on that channel. If I use the splitter, I get 68 on the 622 and 78 on the 722. If anything it should be the other way around since the 722 has a longer run. I'm not complaining since the channel comes in OK but it just makes me wonder........

Why?

 

[gdarwin]

Multipath problems??? Have you tryed repointing the antenna? In the attic could be a problem also. Had to move my antenna to the roof to fix my reception problems.

 

[RandallA]

Multipath problems??? Have you tryed repointing the antenna? In the attic could be a problem also. Had to move my antenna to the roof to fix my reception problems.

I don't think it's the antenna since I get 78% with the 722 and 68% with the 622. It's also only on one channel, all the other ones are at 100%. If I don't use the splitter, I do get the 78% on that channel. I have replaced the splitter with 3 different ones and the same thing happens. It's really a strange problem and I'm leaning towards the tuner on the 622.

 

[gdarwin]

I have 2 receivers on diplexers at my father in law's place - no problems. Have had a 211 and a 622 replaced for OTA reception problems. Call it in.... All receivers in my sig run off the same antenna barefoot...

 

[RandallA]

Per your suggestion, I moved the antenna around a little bit and I now get 83% on the 722 and 70% on the 622 for that channel. I'll play a little more with the antenna over the weekend but that might be enough for me. The rest of the channels come in at 100%.

There's still a difference between the 622 and the 722 tuner though but I don't mind having that channel at 70% while the rest are at 100%. The big test would be to swap the receivers but don't want to get into disconnecting cables right now. Maybe some other time.

 

[oljim]

Both splitters and diplexers reduce signal

 

[RandallA]

Both splitters and diplexers reduce signal

Yes, I know that. The loss for each leg on a 2 way splitter is -3.5 dB and -2.0 loss per diplexer. The thing is that there is no problem with the 722 and is using the same setup, diplexed to the receiver from the same splitter. Actually if anything, I should have lower readings on the 722 since the cable run is at least 50 ft. longer than the 622.

 

[Tech#344]

Some thing else it could be is a poorly made fitting. You mentioned that you were using Quad-shield which has better noise rejection but some times makes it harder to make the fittings properly, and if your using diplexers its probably because your using the cables prewired into your house by the contractor who built it who more than likely to have used crimp type connectors which your almost as likely to be crushed as to be made correctly especially if using RG-6U connectors on RG-6-Quad-shield cable. I would check for a crush, smashed or other wise malformed fitting.

 

[Jim5506]

Try swapping the 722 and the 622 and see what the channel signal strengths do.

If the 622 is still lower than the 722, then it is probably an anomaly with the tuner on the 622, if the lower signal level stays in the same place then there is a loss somewhere along the cable, maybe a harmonic or something.

 

[RandallA]

Try swapping the 722 and the 622 and see what the channel signal strengths do.

If the 622 is still lower than the 722, then it is probably an anomaly with the tuner on the 622, if the lower signal level stays in the same place then there is a loss somewhere along the cable, maybe a harmonic or something.

Yep, that's exactly my next step. I just haven't had the time to do it since I need to get behind the entertainment center to get to the 722.

Tech#344,

No, there aren't any original cables. I cut all of them when I first moved into the house since they were at least 20 yrs. old and RG59 cables. All cabling and fittings are new and made by me. I've tried different jumpers so I'm sure it's not the cabling.