The Official AVS Antenna and Related Hardware Topic! - Page 465 - AVS Forum
Forum Jump: 
Reply
 
Thread Tools
post #13921 of 16253 Old 06-30-2011, 08:17 PM
Member
 
xlr8r's Avatar
 
Join Date: May 2005
Posts: 111
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 11
Quote:
Originally Posted by deltaguy View Post
I would recommend trying a bowtie alone before adding the rabbit ears and bowtie together. The same connector you are using for rabbit ears will work for the bowtie. I say this because, when I combined the 2 antennas with the 4-screw uhf/vhf adapter, my reception was considerably worse for uhf signals. Also, be aware that the bowtie alone may be able to receive vhf high signals. Aim for one channel at a time.

I'm surprised to report that the $4 UHF bowtie from Radio Shack picked up exactly the same set of digital stations that I was receiving with rabbit ears. Does this mean they are all UHF stations or does it mean the UHF antenna also picks up VHF and vice versa? If anything the bowtie gets a slightly better signal.
xlr8r is offline  
Sponsored Links
Advertisement
 
post #13922 of 16253 Old 06-30-2011, 08:44 PM
Advanced Member
 
deltaguy's Avatar
 
Join Date: Apr 2008
Location: solano county
Posts: 907
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 5 Post(s)
Liked: 18
Quote:
Originally Posted by xlr8r View Post
I'm surprised to report that the $4 UHF bowtie from Radio Shack picked up exactly the same set of digital stations that I was receiving with rabbit ears. Does this mean they are all UHF stations or does it mean the UHF antenna also picks up VHF and vice versa? If anything the bowtie gets a slightly better signal.
The bowtie should be slightly better for uhf channels and slightly worse for vhf channels. But, the bowtie is easier angle and angle can be important. For example, having a bowtie facing the ceiling/floor is best for some of my uhf channels here. I'm aiming for a single antenna farm (Walnut Grove). For vhf channels, the bowtie and flat wire in a "T" position works best. It's important that the flat wire not touch metal objects. The bowtie should also give you more placement options, and location is extremely important.

The bowtie probably wouldn't do too well for vhf on rf 2, rf 3 and rf 4. This makes it a "uhf" antenna.
deltaguy is offline  
post #13923 of 16253 Old 07-01-2011, 06:40 AM
AVS Addicted Member
 
arxaw's Avatar
 
Join Date: May 2002
Posts: 10,909
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Quote:
Originally Posted by xlr8r View Post

I'm surprised to report that the $4 UHF bowtie from Radio Shack picked up exactly the same set of digital stations that I was receiving with rabbit ears. Does this mean they are all UHF stations or does it mean the UHF antenna also picks up VHF and vice versa? If anything the bowtie gets a slightly better signal.

If the TV signals are strong enough, most any metal object can work as a UHF or VHF antenna. Even a paper clip or twist tie stuck in the coax port will work sometimes.
arxaw is offline  
post #13924 of 16253 Old 07-01-2011, 08:37 AM
Senior Member
 
Dave Loudin's Avatar
 
Join Date: Nov 2007
Location: King George, VA
Posts: 409
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 11
That's why we like to see an estimate of how much RF is in the air via tools like TVFool before making any qualitative statements.
Dave Loudin is offline  
post #13925 of 16253 Old 07-01-2011, 11:53 PM
AVS Special Member
 
300ohm's Avatar
 
Join Date: May 2008
Location: Somewhere in Delaware
Posts: 1,823
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 11
Quote:
Does this mean they are all UHF stations or does it mean the UHF antenna also picks up VHF and vice versa? If anything the bowtie gets a slightly better signal.
Did you post your TVFool report somewhere ?

The Radio Shack Classic bowtie is a favorite of mine, Ive had one since about 1968 when it was about $0.49 at the time, heh. From my modeling and real life testing, it does have about a 1 - 2 dbi gain over a typical simple 6 inch uhf loop on most channels. It does need to be rescaled for the new uhf range. And they should use copper or aluminum instead of stainless steel, even though stainless steel is tougher.
300ohm is offline  
post #13926 of 16253 Old 07-05-2011, 05:43 PM
Senior Member
 
Satcom15's Avatar
 
Join Date: May 2007
Location: Colorado Springs CO
Posts: 472
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Quote:
Originally Posted by SFischer1 View Post

Hi,

IMHO KCSM could not survive without pulling the PBS plug, they had been moving away for years.

They have to have programming that is not duplicated on NCPB to gather enough pledges. Their 24/7/365 pledge notes continue.

Their pulling the plug was done along with a call for $2M by the end of the year (Two Months) or they would go off the air. The company that built their HDTV equipment made a press release about their $$$$$ equipment being sold to KCSM about the same time. Really bad timing. Also the bill for rebuilding Sutro was coming due.

http://sutrotower.com/

While they have just as good HDTV signal as KQED both transmitting from Sutro tower, KCSM often shows 16:9 material letter boxed and pillared to my dismay. Perhaps they can pay less for programming this way.

I made this post to [HDTV-in-SFbay]:

http://tech.groups.yahoo.com/group/HDTV-in-SFbay/





The same can be said for KCSM and I suspect KCET.

SHF

Always interesting to hear about TV stations in the SF Bay Area (moved to Cupertino in 1960 from Stockton and spent the 60s and 70s formative years living there). Have any of you looked into satellite transmission of the national PBS feed? There's a guy in Pueblo (south of me in Colorardo Springs) that does it and he is very happy with it - our local PBS channel is the pitts picture and programming quality wise (I get soooo tired of Antiques Road Show). He gets the full HD broadcast and there is just the one time equipment cost which isn't all that much. BTW, I remember watching Sutro Tower being built - my grandma lived in the Mission District and near the corner of Haight and Ashbury in the 60s, on Social Security no less. My mom couldn't stand visiting her - all those "dirty hippies" I thought it was a hoot.
Satcom15 is offline  
post #13927 of 16253 Old 07-05-2011, 09:18 PM
AVS Special Member
 
SFischer1's Avatar
 
Join Date: Sep 2005
Location: Sunnyvale, CA 94087
Posts: 1,748
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 26 Post(s)
Liked: 20
Quote:
Originally Posted by Satcom15 View Post

... Have any of you looked into satellite transmission of the national PBS feed? There's a guy in Pueblo (south of me in Colorardo Springs) that does it and he is very happy with it - our local PBS channel is the pitts picture and programming quality wise (I get soooo tired of Antiques Road Show). He gets the full HD broadcast and there is just the one time equipment cost which isn't all that much. ...

Hi,

With NCPB (KQED, KTEH, KQET) sending six streams of programming (With additional dups.) and KCSM sending two (KCSM, MHz, jazz) my 5-7 tuners capture more than I can watch.

I have finally made some headway in reducing the backup on my N.A.S. (1TB) that started with the Winter Olympics.

I get all the HD PBS content from KQED I want with endless reruns in SD.

I just counted twelve (12) showings of "A Capitol Fourth 2011" with four (4) in HD. I had to cancel eleven (11) of the showings that my automatic scheduling program set up.

With 78 streams available here, Satellite is overkill. The ~ 24 hours / day movie channel just had to drop their power down (KTNC). I get the Twenty (20) streams on Channel on (1) (KAXT) just fine.

Want to see the entire list, no I do not get or want some stations, look here:
Quote:
Larry
SF
__________________
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

SHF
SFischer1 is offline  
post #13928 of 16253 Old 07-05-2011, 09:36 PM
Senior Member
 
Satcom15's Avatar
 
Join Date: May 2007
Location: Colorado Springs CO
Posts: 472
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Quote:
Originally Posted by SFischer1 View Post

Hi,

With NCPB (KQED, KTEH, KQET) sending six streams of programming (With additional dups.) and KCSM sending two (KCSM, MHz, jazz) my 5-7 tuners capture more than I can watch.

I have finally made some headway in reducing the backup on my N.A.S. (1TB) that started with the Winter Olympics.

I get all the HD PBS content from KQED I want with endless reruns in SD.

I just counted twelve (12) showings of "A Capitol Fourth 2011" with four (4) in HD. I had to cancel eleven (11) of the showings that my automatic scheduling program set up.

With 78 streams available here, Satellite is overkill. The ~ 24 hours / day movie channel just had to drop their power down (KTNC). I get the Twenty (20) streams on Channel on (1) (KAXT) just fine.

Want to see the entire list, no I do not get or want some stations, look here:

Larry
SF
__________________
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

SHF

Holy Cow! You are so lucky. I noticed there was nothing from Loma Prieta. KNTV is now broadcasting from San Bruno Mtn as the NBC affiliate and not KRON (Ind)? Interesting. When did that happen and why? I can recall watching the news on KRON sponsored by Palmolive in the 60s. Art Brown and Jerry Jensen. I'm showing my age. LOL
Satcom15 is offline  
post #13929 of 16253 Old 07-06-2011, 01:06 PM
Senior Member
 
oc-rdx's Avatar
 
Join Date: May 2008
Location: Irvine, CA
Posts: 242
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 15
SFischer1,

I saw on your list of stations that you indicated that only RF 2-51 are being used for television. We currently have two stations in LA area that are on RF 52 & 55. RF52 is KFLA 8 & RF 55 is KNLA 20. KNLA 20 is also on RF 50.
oc-rdx is offline  
post #13930 of 16253 Old 07-06-2011, 01:37 PM
Advanced Member
 
LithOTA's Avatar
 
Join Date: May 2010
Location: Lake in the Hills, IL
Posts: 948
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
2-51 for digital tv, there are still analogs between 52 & 69.
LithOTA is offline  
post #13931 of 16253 Old 07-06-2011, 02:02 PM
AVS Special Member
 
SFischer1's Avatar
 
Join Date: Sep 2005
Location: Sunnyvale, CA 94087
Posts: 1,748
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 26 Post(s)
Liked: 20

ABC, NBC follies


 

 

 

Quote:

Originally Posted by Satcom15 View Post

... KNTV is now broadcasting from San Bruno Mtn as the NBC affiliate and not KRON (Ind)? Interesting. When did that happen and why? ...


Hi,

It was very interesting.

First KGO paid KNTV to stop carrying ABC as they were duplicating their signal in the South Bay. That ended ABC OTA in Salinas / Monterey.

Then NBC demanded so much money from KRON to continue carrying their programs, a sum so huge that they could not make money if they paid.

It was up in the air if NBC would buy KRON or KNTV. I heard of two factors that may have mattered. KRON had shown a multi-part Russian Documentary on WWII instead of NBC shows. That did not make NBC happy at all.

NBC wanted to dip into the talent and thinking of Silicon Valley, KNTV had built a new studio on North First street in San Jose. KNTV had started carrying NBC shows at that point.

So NBC purchased KNTV.

Then KNTV threw KCSM's analog transmitter off of Bruno and they had no analog signal for a very long time, putting a flea power transmitter on the air that just covered their city of license when the FCC demanded that they do so. KCSM had a digital transmitter on Sutro by then as new antennas allowing multiple transmitters had been developed at that time.

KNTV then moved their transmitter North to Mt. San Bruno.

KRON still says they are "The Bay Area's News Station" but clearly KTVU and KGO are now.

KRON is finally profitable now but only ~ two of the talent remains from the old days.

ABC is now back OTA this spring in Salinas / Monterey being carried as the second 16:9 stream on KSBW's transmitter. The KSBW news is shown on both streams and KGO is gone from Cable and Satellite in that market. So Both NBC and ABC on KSBW. KSBW had moved their transmitter South to Fremont Peak.

KNTVs and KSBWs old towers are still up, KNTV has kept theirs but KSBW sold theirs. Loma Prieta has a pending LP station.

 

EDIT: 9/26/2013

KRON and one other San Francisco station now has news on Salinas / Monterey cable.

SHF

SFischer1 is offline  
post #13932 of 16253 Old 07-06-2011, 02:04 PM
AVS Special Member
 
SFischer1's Avatar
 
Join Date: Sep 2005
Location: Sunnyvale, CA 94087
Posts: 1,748
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 26 Post(s)
Liked: 20
Quote:
Originally Posted by oc-rdx View Post

SFischer1,

I saw on your list of stations that you indicated that only RF 2-51 are being used for television. We currently have two stations in LA area that are on RF 52 & 55. RF52 is KFLA 8 & RF 55 is KNLA 20. KNLA 20 is also on RF 50.

Hi,

Sorry, it is NOT my list!

Here one of Larry's posts that I stole the links from.

http://www.avsforum.com/avs-vb/showt...4#post20640204

SHF
SFischer1 is offline  
post #13933 of 16253 Old 07-07-2011, 01:03 PM
AVS Special Member
 
Falcon_77's Avatar
 
Join Date: May 2007
Location: OC, CA
Posts: 2,602
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Quote:
Originally Posted by LithOTA View Post

2-51 for digital tv, there are still analogs between 52 & 69.

The stations on 52 & 55 mentioned above are digital.

52-69 can be used for low power digital if they prove that there are no channels "available" in core. I put available in quotes as 2-5 are most definitely empty here right now, but there are applications which these stations used to justify them not being available.

Most LD's seem to realize that 15kW on UHF is much, much better than 0.3kW on Low-VHF.

Note that the LA area still has analogs on 57 & 67, so there are 4 low power TV stations still/now operating above 51. Also, the 2 digitals are both quite new. 55 wasn't vacant for long after MediaFLO went off the air and 52 fled 8 due to co-channel from San Diego.

Yes, we need more not less RF channels for TV in the LA area, so 2-69 and 7-69 antennas are not obsolete yet.
Falcon_77 is offline  
post #13934 of 16253 Old 07-07-2011, 05:02 PM
AVS Special Member
 
ProjectSHO89's Avatar
 
Join Date: Feb 2009
Posts: 2,533
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 22 Post(s)
Liked: 60
Keep in mind that when the new owners of the 700+ spectrum (ATT & Verizon) are ready for their new wireless real estate, they'll boot the last remaining broadcasters of these upper frequencies with little notice.
ProjectSHO89 is offline  
post #13935 of 16253 Old 07-09-2011, 07:45 AM
Senior Member
 
Satcom15's Avatar
 
Join Date: May 2007
Location: Colorado Springs CO
Posts: 472
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Quote:
Originally Posted by SFischer1 View Post

Hi,

With NCPB (KQED, KTEH, KQET) sending six streams of programming (With additional dups.) and KCSM sending two (KCSM, MHz, jazz) my 5-7 tuners capture more than I can watch.

I get all the HD PBS content from KQED I want with endless reruns in SD.

I just counted twelve (12) showings of "A Capitol Fourth 2011" with four (4) in HD. I had to cancel eleven (11) of the showings that my automatic scheduling program set up.

SHF

Talk about an embarresment of riches! You lucky dog. Our PBS programming is the pitts here. They cram their normal programming, VME (Spanish programming), and Create into one channel. So we never get the full bandwidth allocated to their premier programs. Tiling, audio dropouts, etc. are common. Apparently, the national feed downlink is in Denver then they shoot the signal to Cheyenne Mountain via microwave link for transmission in Southern CO. Its the pitts. Thus the interest in receiving the national feed satellite broadcast.
Satcom15 is offline  
post #13936 of 16253 Old 07-09-2011, 08:19 AM
Senior Member
 
Ennui's Avatar
 
Join Date: Oct 2005
Location: San Marcos, CA
Posts: 405
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 14
I watch Riverside KVCR PBS (24.1, .2 .3 .4); KCET LA (28.1 .2 .3 .4) most of the time; KOCE PBS Orange County (50.1, .2 .3 .4) and KLCS LA (58.1 .2 .3 .4) all OTA plus a single HD channel on cable KPBS San Diego. Only the .1 channel of the OTA channels is in HD. I set up an outdoor antenna 15 years ago to get these channels.

99.5% Dark Matter
Ennui is offline  
post #13937 of 16253 Old 07-09-2011, 04:10 PM
Advanced Member
 
LithOTA's Avatar
 
Join Date: May 2010
Location: Lake in the Hills, IL
Posts: 948
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
I also have it pretty good when in comes to PBS. I get WTTW, WYCC, and WMVT 24/7, WMVS and WYIN every night, and WHA on some nights. All together, it's about 20 subchannels of PBS.
I have an antenna for the kid's rooms that gives them all the PBS and Qubo that they want.
LithOTA is offline  
post #13938 of 16253 Old 07-13-2011, 05:08 PM
Senior Member
 
Satcom15's Avatar
 
Join Date: May 2007
Location: Colorado Springs CO
Posts: 472
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Quote:
Originally Posted by LithOTA View Post

I also have it pretty good when in comes to PBS. I get WTTW, WYCC, and WMVT 24/7, WMVS and WYIN every night, and WHA on some nights. All together, it's about 20 subchannels of PBS.
I have an antenna for the kid's rooms that gives them all the PBS and Qubo that they want.

I should be so lucky with PBS. Its so lousy here and Rocky Mtn PBS keeps begging for $$$ - so I can watch more of Antiques Roadshow?. *sigh*
Satcom15 is offline  
post #13939 of 16253 Old 07-13-2011, 09:20 PM
AVS Special Member
 
300ohm's Avatar
 
Join Date: May 2008
Location: Somewhere in Delaware
Posts: 1,823
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 11
You can get most of the good PBS videos on PBS.org.
300ohm is offline  
post #13940 of 16253 Old 07-20-2011, 08:53 AM
Newbie
 
Clearce's Avatar
 
Join Date: Aug 2010
Posts: 9
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
HI, just wanted to mention good results with a newer indoor antenna.The model is Philips SDV6122t/27. My tvfool showed green for all stations of interest and I am under 5 miles for all with only 18 deg difference. I am in the city,(Philadelphia) but not downtown.
I have had poor results using a rs delta rabbit ears and a bad RS 15-1878 unpluged. I could get all my stations with the other antennas but not at the same time.
The new antenna is powered 20db something I was going to avoid to prevent overload. Also the rabbit ears much to my surprise are short,(16" fully extended). The surprise is that when first tryed in the same spot my old antenna was in , I got all my stations at once.

It claims to have a low noise transformer and to have a noise filter. I will need to do a little tuning but I am shocked to be able to click through all my channels and have them all show up with out moving anything.

The performance of this newer design is impressive. This is not older scary powered antennaes that are worse plugged in than not. If you live close to your towers but some rabbit ears are giving you fits try this. I needed low vhf, hivhf and mostly uhf and this came through right away. I was really going to try the RS 1874 budget ears, but the Radio shack didn't have any in stock that weren't damaged or defective, so they said. I would have compared the budget ears to the Phillips if I could have. I am done now.

I am shocked that a powered attenna ( with gain initialy turned all the way down) worked so well. And when I saw those mini dipoles I thought I was in trouble.
Someone who designed this antenna new what they were doing.

If you have to fiddle around with your indoor antennae too much, It may to try one of theese before you go attic or outdoor.
Clearce is offline  
post #13941 of 16253 Old 07-25-2011, 08:20 PM
Advanced Member
 
LithOTA's Avatar
 
Join Date: May 2010
Location: Lake in the Hills, IL
Posts: 948
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
A lesson in proper antenna mast grounding-

http://lakeinthehills.patch.com/arti...-homes-in-lith

The first house, with photos, is only a few hundred yards away from me. Being one of the only homes in my subdivision with an antenna, I have examined it, and I didn't see a ground wire headed down any side of the house.
I guess my ground install is up to snuff.
LithOTA is offline  
post #13942 of 16253 Old 07-26-2011, 03:10 AM
AVS Special Member
 
mikepier's Avatar
 
Join Date: Sep 2006
Location: Long Island and Upstate NY
Posts: 2,437
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 19
Quote:
Originally Posted by LithOTA View Post

A lesson in proper antenna mast grounding-

http://lakeinthehills.patch.com/arti...-homes-in-lith

The first house, with photos, is only a few hundred yards away from me. Being one of the only homes in my subdivision with an antenna, I have examined it, and I didn't see a ground wire headed down any side of the house.
I guess my ground install is up to snuff.

Even if that antenna was grounded, and lessen the chances of a strike, it still would not have prevented that damage if lightning did strike. But just goes to show how important it is to ground your antenna.
mikepier is offline  
post #13943 of 16253 Old 07-26-2011, 08:23 AM
Advanced Member
 
LithOTA's Avatar
 
Join Date: May 2010
Location: Lake in the Hills, IL
Posts: 948
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Quote:
Originally Posted by mikepier View Post


Even if that antenna was grounded, and lessen the chances of a strike, it still would not have prevented that damage if lightning did strike. But just goes to show how important it is to ground your antenna.

There are a lot of other things nearby that could've been struck- cell towers, some very tall power poles, a lightning-detection and warning system at the park, not to mention my own mast and a few others- all within a few hundred yards of the house that was hit.
I might just beef up my own grounding stuff, just to be safe.
LithOTA is offline  
post #13944 of 16253 Old 07-29-2011, 06:53 PM
Advanced Member
 
LithOTA's Avatar
 
Join Date: May 2010
Location: Lake in the Hills, IL
Posts: 948
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Is this a CM 4248?

This antenna is on the home of an elderly in-law who has moved into assisted living. It looks to me like the original 4248, with extra wide reflector and diamond-shaped directors.
Can anyone confirm?
LL
LithOTA is offline  
post #13945 of 16253 Old 07-30-2011, 08:11 AM
AVS Special Member
 
tylerSC's Avatar
 
Join Date: Jun 2010
Location: Mauldin SC, 29607
Posts: 3,960
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 53 Post(s)
Liked: 89
Yes that does appear to be the original CM4248 with the diamond shaped elements. Similar to the 43XG but the diamond elements are solid sheets of metal that, IMO, capture more signal than the hollow X shaped elements of the 43XG. Have tested them both and got better results with the 4248. Plus better build quality. They also made a 4257 which is comparable to the 91XG. Wish they still made them, but we all know that story. Anyway, I would hang on to the one you have there. Excellent UHF antenna, along with their original 4228 as well.
tylerSC is offline  
post #13946 of 16253 Old 07-30-2011, 08:38 AM
Advanced Member
 
LithOTA's Avatar
 
Join Date: May 2010
Location: Lake in the Hills, IL
Posts: 948
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Thanks Tyler, I figured it was because other Yagis don't have that wide reflector. I'm going to post it in the AVS classifieds, with the provision that the buyer will have to climb up and get it. It's in western Illinois, right in Winegard's back yard.
They also have some kind of rotor controller- it will be delivered to me later today. I told the wife to bring anything antenna-related, as we want to help her Grandmother maximize her proceeds from the sale of her stuff.

Edit Sunday 11:45 CDT-
Ok, I got a whole goody bag worth of stuff- cables, a pair of RCA CECBs, a Radio Shack Preamp, and this Cornell-Dubilier HAM-II/CD44 rotator control box. I will list it on ebay.
LL
LithOTA is offline  
post #13947 of 16253 Old 08-08-2011, 01:42 PM
Advanced Member
 
LithOTA's Avatar
 
Join Date: May 2010
Location: Lake in the Hills, IL
Posts: 948
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
If you could please open up the attached schematic, my crazy question makes some sense.

Tuner B gets the combined signals from Antennas A & B. So whille all of the signals are weakened, as long as they are strong enough, it's a sucessful combine. No questions about that.
But note how Tuner A gets signal from Antenna A only, since the splitter is upstream of the combiner. So here's the question-

Is Tuner A's signal compromised by the combining that occurs at Splitter B?
Or does Tuner A get the same signal as it would if Antenna B and Splitter B were taken out of the system?

Thank you for your help.

 

Combiner Schematic.pdf 44.2275390625k . file
Attached Files
File Type: pdf Combiner Schematic.pdf (44.2 KB, 1 views)
LithOTA is offline  
post #13948 of 16253 Old 08-09-2011, 08:06 AM
AVS Special Member
 
300ohm's Avatar
 
Join Date: May 2008
Location: Somewhere in Delaware
Posts: 1,823
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 11
Theres another fly in the ointment with the pictured scenario, the antennas are 90 degrees to each other.
So yes, tuner A's signal is compromised by the combining that occurs at Splitter B.

I cant really imagine a situation that would use the above scenario efficiently. If the signals were strong enough to permit combining two 90 degree opposing antennas, then just couple them at the mast, run the downlead, then split to the two tuners.
300ohm is offline  
post #13949 of 16253 Old 08-09-2011, 09:00 AM
Advanced Member
 
LithOTA's Avatar
 
Join Date: May 2010
Location: Lake in the Hills, IL
Posts: 948
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Quote:
Originally Posted by 300ohm View Post

Theres another fly in the ointment with the pictured scenario, the antennas are 90 degrees to each other.
So yes, tuner A's signal is compromised by the combining that occurs at Splitter B.

I cant really imagine a situation that would use the above scenario efficiently. If the signals were strong enough to permit combining two 90 degree opposing antennas, then just couple them at the mast, run the downlead, then split to the two tuners.

Thanks 300.
This was more theoretical than anything else, I just wondered if splitting off before the combine would isolate that tuner. Good to get the straight dope on these engineering issues.
LithOTA is offline  
post #13950 of 16253 Old 08-09-2011, 09:30 AM
AVS Special Member
 
holl_ands's Avatar
 
Join Date: Jun 2004
Location: San Diego, CA
Posts: 3,591
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 18 Post(s)
Liked: 52
Each Splitter generally provides 25-35+ of Isolation between the input ports (YMMV).

Hence the signals from Antenna B are reduced by about 50-70+ dB before they reach Tuner A.
Unless you have some REALLY strong signals coming in on Antenna B, there should be no problems.
holl_ands is offline  
Reply HDTV Technical

Tags
Channel Master Cm 4228 8 Bay Hdtv Uhf Antenna Cm4228hd
Gear in this thread

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page


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