San Francisco, CA - OTA - Page 501 - AVS Forum | Home Theater Discussions And Reviews
Forum Jump: 
 167Likes
Reply
Thread Tools
post #15001 of 15008 Unread Yesterday, 03:37 PM
Member
 
gone hiking's Avatar
 
Join Date: Jul 2009
Location: South San Jose/Santa Teresa
Posts: 20
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 6 Post(s)
Liked: 10
Quote:
Originally Posted by lifespeed View Post
All I can suggest (I'll probably do this myself) is a real, directional, high-gain VHF Yagi like Stellar Labs 30-2476 combined with a good UVSJ like the one from Antennas Direct.
Not sure if there's a difference with what I have and the one in the link. Model #s are almost the same. Mind has an "S" at the end and the other has a "Z". In trying different configurations I discovered water inside the grommet on the Clearstream connector. When I disconnected the DB2e to islolate the Clearstream to see if it would improve VHF from Mt Sutro, it was a complete failure. So I reconnected everything through the combiner like before and now virtually no VHF at all. UHF is a little worse with just the DB2e though. I think water did something to the electronics inside the Clearstream box where the coax connects and my fiddling with it set it over the edge somehow. If I replace it with a VHF only antenna, I may have to also get something better for UHF.
Attached Thumbnails
Click image for larger version

Name:	20170425_124025.jpg
Views:	13
Size:	206.1 KB
ID:	2102649  
gone hiking is offline  
Sponsored Links
Advertisement
 
post #15002 of 15008 Unread Yesterday, 04:06 PM
AVS Forum Special Member
 
lifespeed's Avatar
 
Join Date: May 2005
Location: San Jose, CA
Posts: 1,569
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 66 Post(s)
Liked: 11
Quote:
Originally Posted by gone hiking View Post
Not sure if there's a difference with what I have and the one in the link. Model #s are almost the same. Mind has an "S" at the end and the other has a "Z". In trying different configurations I discovered water inside the grommet on the Clearstream connector. When I disconnected the DB2e to islolate the Clearstream to see if it would improve VHF from Mt Sutro, it was a complete failure. So I reconnected everything through the combiner like before and now virtually no VHF at all. UHF is a little worse with just the DB2e though. I think water did something to the electronics inside the Clearstream box where the coax connects and my fiddling with it set it over the edge somehow. If I replace it with a VHF only antenna, I may have to also get something better for UHF.
That looks like the correct part to combine the antennae, model number differences aside. However, if you simply open-circuited the UHF port when you disconnected the DB2e that is electrically incorrect; the unused port should have been terminated with 75 ohms. If you want to look only at the Clearstream VHF and don't have a 75 ohm termination handy, you can can join the antenna cable to the TV cable with an F connector female adapter, removing both the diplexer and the UHF antenna from the circuit. Water is not a good thing.

I see a couple options here:

1) Replace the diplexer on the assumption it was water damaged and that is the source of your problems. This presumes your setup worked well over the full range of weather and seasons, not just for a couple weeks or months. Not clear if this was ever a truly good setup, have to judge by your experience with it.

2) Change out both antennae for high-gain narrow beam models to improve signal level and reject off-axis multipath. Chances are you'll just be able to point at Mt. Sutro and pick up Mt. Allison anyway (works for me). RF35 will probably still be flaky, but you should get RF7 from Sutro anyway. I have had great results with the XG91 on UHF, haven't yet tried the Stellar VHF but the specs are good.

My impression is the narrow beam is at least as important as higher gain.

Lifespeed
lifespeed is offline  
post #15003 of 15008 Unread Yesterday, 04:50 PM
Member
 
gone hiking's Avatar
 
Join Date: Jul 2009
Location: South San Jose/Santa Teresa
Posts: 20
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 6 Post(s)
Liked: 10
Quote:
Originally Posted by lifespeed View Post
That looks like the correct part to combine the antennae, model number differences aside. However, if you simply open-circuited the UHF port when you disconnected the DB2e that is electrically incorrect; the unused port should have been terminated with 75 ohms. If you want to look only at the Clearstream VHF and don't have a 75 ohm termination handy, you can can join the antenna cable to the TV cable with an F connector female adapter, removing both the diplexer and the UHF antenna from the circuit. Water is not a good thing.

I see a couple options here:

1) Replace the diplexer on the assumption it was water damaged and that is the source of your problems. This presumes your setup worked well over the full range of weather and seasons, not just for a couple weeks or months. Not clear if this was ever a truly good setup, have to judge by your experience with it.

2) Change out both antennae for high-gain narrow beam models to improve signal level and reject off-axis multipath. Chances are you'll just be able to point at Mt. Sutro and pick up Mt. Allison anyway (works for me). RF35 will probably still be flaky, but you should get RF7 from Sutro anyway. I have had great results with the XG91 on UHF, haven't yet tried the Stellar VHF but the specs are good.

My impression is the narrow beam is at least as important as higher gain.
Actually I bypassed the diplexer and connected the Clearstream directly to the house coax and got no VHF reception. So that tells me the water damage is with the Clearstream electronics. I think you're right that this was a less than ideal setup to begin with. So I'm going with your suggestion to get a directional VHF and eventually a directional UHF also. But first I'll explore my options under Antenna Direct's lifetime warranty. Thanks again for your input.
gone hiking is offline  
 
post #15004 of 15008 Unread Yesterday, 04:56 PM
AVS Forum Special Member
 
Larry Kenney's Avatar
 
Join Date: Nov 2001
Location: San Francisco, CA
Posts: 3,316
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 515 Post(s)
Liked: 81
The San Francisco Chronicle published an article on "Airwave Sale Nets Windfall at Stations" on April 21. It shows what each station will get from the sale of their spectrum.

To read it go to:
http://digital.olivesoftware.com/Oli...iscoChronicle/
Search 4/21/17 for "Airwave Sale".

Larry
rdvegas likes this.

My complete SF Bay Area DTV Station Lists: http://www.choisser.com/sfonair.html
Lots of Broadcasting links and information: http://www.choisser.com/broadcast.html
Live reception scans from my HD Home Run receivers: http://www.larrykenney.com/hdhr/
Photos and info on my antennas: http://www.larrykenney.com/tvantennas.html
Larry Kenney is offline  
post #15005 of 15008 Unread Yesterday, 05:03 PM
AVS Forum Special Member
 
Larry Kenney's Avatar
 
Join Date: Nov 2001
Location: San Francisco, CA
Posts: 3,316
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 515 Post(s)
Liked: 81
Gone Hiking, I have a Clearstream 5 which I use with a Channel Master 4228 for the bedroom TV. See attached photo. It also shows my Dish antenna.

The C5 is a rather weird looking antenna and I don't really know how good it is. I only use it to receive KGO 7 and KNTV 12, both within 5 miles of my home. I know that it has never received the VHF stations from Walnut Grove, 65 miles from here.

Larry
Attached Thumbnails
Click image for larger version

Name:	antenna1.jpg
Views:	17
Size:	210.5 KB
ID:	2102713  

My complete SF Bay Area DTV Station Lists: http://www.choisser.com/sfonair.html
Lots of Broadcasting links and information: http://www.choisser.com/broadcast.html
Live reception scans from my HD Home Run receivers: http://www.larrykenney.com/hdhr/
Photos and info on my antennas: http://www.larrykenney.com/tvantennas.html
Larry Kenney is offline  
post #15006 of 15008 Unread Yesterday, 05:49 PM
Advanced Member
 
888CALLFCC's Avatar
 
Join Date: Jul 2009
Location: Hayward, CA
Posts: 833
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 206 Post(s)
Liked: 30
Quote:
Originally Posted by gone hiking View Post
Not sure if there's a difference with what I have and the one in the link. Model #s are almost the same. Mind has an "S" at the end and the other has a "Z". In trying different configurations I discovered water inside the grommet on the Clearstream connector. When I disconnected the DB2e to islolate the Clearstream to see if it would improve VHF from Mt Sutro, it was a complete failure. So I reconnected everything through the combiner like before and now virtually no VHF at all. UHF is a little worse with just the DB2e though. I think water did something to the electronics inside the Clearstream box where the coax connects and my fiddling with it set it over the edge somehow. If I replace it with a VHF only antenna, I may have to also get something better for UHF.
One simple way to test VHF from sutro tower ... is simply tune your car radio to a sutro tower FM radio station... like 96.5
Driving around you will hear flutter (multipath) and total dead zones. Use regular FM, not HD-FM.

Some parts of San Jose get Monterey VHF-TV 8 & 13
So usually something will come in. No signal makes questionable equipment, cable, or splitter failure suspect.
888CALLFCC is offline  
post #15007 of 15008 Unread Today, 12:11 PM
AVS Forum Special Member
 
Calaveras's Avatar
 
Join Date: Jan 2007
Location: Mountain Ranch
Posts: 5,090
Mentioned: 7 Post(s)
Tagged: 0 Thread(s)
Quoted: 1180 Post(s)
Liked: 266
Quote:
Originally Posted by Larry Kenney View Post
The San Francisco Chronicle published an article on "Airwave Sale Nets Windfall at Stations" on April 21. It shows what each station will get from the sale of their spectrum.

To read it go to:
http://digital.olivesoftware.com/Oli...iscoChronicle/
Search 4/21/17 for "Airwave Sale".

Larry

Requires a subscription.

Chuck
Calaveras is offline  
post #15008 of 15008 Unread Today, 05:55 PM
Newbie
 
minakami's Avatar
 
Join Date: Dec 2006
Location: Mountain View, CA
Posts: 8
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 8 Post(s)
Liked: 2
Quote:
Originally Posted by lifespeed View Post
I have two completely separate antennae and tuners with fairly different characteristics. While tuned to KGO RF35 repeater, I get the same problem on both antenna. I can put up an instance of each antenna/tuner on my TV (I use an HTPC) and view the breakups occur on both antenna simultaneously. It is extremely rare for one antenna to pixelate when the other does not. The antenna are separated by a couple feet vertically, and aimed in different directions 45 degrees apart with the Yagi pointed at Mt. Sutro and the bowtie aimed towards Mt. Allison.

I would think if this were a multipath problem there would be some differences in reception between the two antennae. I'm not sure a single reply to the topic of the KGO repeater has indicated some people get good reception from it.


A bit late to the party (taxes & life got in the way). I'm now seeing two issues with RF35 - over the past few weeks reception has degraded. The hdhomerun on the DB4E pointed at Mt. Allison is having a tough time demodulating the signal. At the same time, the CM4228HD that I have pointed at Sutro is now picking up RF35 better than the DB4E. Possibly via a side lobe. (Interference with KICU RF36...as others are suggesting...is certainly a possibility, though in my case multipath is more likely. Wish I had a spectrum analyzer to check.)


The other issue is the one I posted here earlier - 5 - 6 times/s a packet is getting lost on RF35. This causes rather minor but constant artifacts on 7-1. A bit more digging (and comparing RF7 to RF35) showed that for every packet that got lost, another stuffing NULL packet was introduced. The most likely place for this to happen is on the broadcast side after the encoder and before/at the stat mux. Interestingly RF7 and RF35 appear to have slightly different bitrates. RF35 has some extra NULL packets. Makes me wonder if that could be giving the stat mux heartache. (Actually I'd think there'd be two different muxes for RF7 and RF35, but with only one encoder for both things could get very interesting.).


Anyway, sent a more detailed description of this to the chief engineer at KGO, though with NAB going on I don't expect much to happen soon.
minakami is online now  
Sponsored Links
Advertisement
 
Reply Local HDTV Info and Reception



Forum Jump: 

Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off