AVS Forum banner
Status
Not open for further replies.
1 - 20 of 274 Posts

·
Registered
Joined
·
634 Posts
This has been a great thread! Thanks to Bob Ross and others for providing so much useful information.

Always liking to crash a free party, I'm curious about the latest projections (pun intended) for the tour/party in Needham.
 

·
Premium Member
Joined
·
7,158 Posts
"You made the biggest thread in the forums history."


Yessssssss.


Now that the votes are in on OAR, we just need to fix WHDH....


Tim

 

·
Registered
Joined
·
1,015 Posts
Hey I didn't get to vote on 14:3 or 4:3, darn work and the holidays kept my visits here limited. I was leaning on the 14:9 side for a while but now that I have watched WBZ-DT in 4:3 I like it better. However PLEASE let's try the gray bars.


Happy New Year Everyone
 

·
Registered
Joined
·
88 Posts
Hi,

I was also away on vacation and would like to add my 2 cents to the discussion. I prefer the screen formats to reflect the actual material. That means I prefer 4:3 for upconverted NTSC and 16:9 for HD. I do not like the distorted geometry of 14:9.


I am looking forward to the get together, hope it is soon.


Pat


------------------

HDjunky
 

·
Registered
Joined
·
1,418 Posts
Hi Early Adopters,


I have had to put off the January 13 Boston DTV open house for a number of reasons, not the least of which is that construction is still going on at the tower site. I had hoped that the tower crew would be long gone by now but the weather situation, as usual, is killing us and Channel 2 is still operating on a temporary antenna.


I have been twisting Bob Ross' arm (CBS VP/Engineering) to attend our open house to address your CBS questions and I think he will (and I know he reads this thread http://www.avsforum.com/ubb/smile.gif ). I also had Tweeter confirmed to bring in a few DTV sets and a new set-top box. Tweeter has no problem delaying the date but will have to sell the set-top box they have been holding for our open house since they have over a thousand customers waiting in line for set-top boxes (who says no one is interested in HDTV?) Anyway, we are looking at April or May.


So...now that you all have your DTV, don't stop reading this thread. Stay tuned for the open house details.


- Bob


[This message has been edited by Bob Hess (edited 01-03-2001).]
 

·
Registered
Joined
·
1,418 Posts
Quote:
Originally posted by George Mills:
tshort, you are correct, but Bob said that the equipment they have now does not allow your option 1 (which I believe everyone would like). I asked for it also a while back.


So Bob has asked us to choose between option 2 and 3. My vote was for option #2. Yes, my ultimate solution vote is for option #1 also.


Notice also that the only stations that do broadcast true HDTV 16x9 do not use option #1 for 4:3 source material.


Bob will option #1 ever be possible?
Option one is NOT an option today or in the near future. I can't comment beyond that at this point. I am sensitive to the aspect ratio questions. We are playing around with the side panel idea.


Bob

 

·
Premium Member
Joined
·
7,158 Posts
Bob,


Looking forward to the get together whenever it occurs. Bob Ross would be quite a bonus as would a comparison of the newer STBs.


Fellow Bostonians,


Despite the "overwhelming" response to OAR, I was being somwhat dry of wit in saying the votes were all in....


Tim

Please join me in the call to arms on WHDH.
 

·
Registered
Joined
·
144 Posts
Hi Bob,


Thanks for all the hard work and good advice.


I didnt think I would be interested to touring the site, but I am changing my mind. In particular if someone from CBS might show up. I would like to thank and encourage them. If they are reading and believing the drivel in the papers lately about HD they might be discouraged and that would be a shame as well as unnecessary.
 

·
Registered
Joined
·
1,418 Posts
Hi Jon and welcome to the Forum,


Try a Radio Shack double Bow-tie set top antenna ($15) before you do anything else and let me know how it works.


Bob Hess

Director, Broadcast Operations/Engineering

WBZ
 

·
Registered
Joined
·
1,015 Posts
Hi Jon and welcome,


Bob's suggestion is a very good one. There is another forum poster who is right around you and he attempted everything you can imaging with aweful results but the little cheap bow tie did the trick.


It's sure is great to see the Boston area HDTV early adopters contingency growing, again welcome.
 

·
Registered
Joined
·
144 Posts
Quote:
Originally posted by Richard_P_Harvey:
Hi Jon and welcome,


Bob's suggestion is a very good one. There is another forum poster who is right around you and he attempted everything you can imaging with aweful results but the little cheap bow tie did the trick.


It's sure is great to see the Boston area HDTV early adopters contingency growing, again welcome.


That would probably be me (I have a newly aquired antenna museum to prove it). The bow-tie antenna seems to indeed be the ticket. Not too much gain and great at rejecting multi-path which was killing the digital signals at my house (about 5 miles SW of the towers) despite not seeming to be a big problem with most analog UHF.


Radio Shack didnt have the bow-tie antenna in the store so I ended up with a 4 element Wineguard bowtie from U-Do-It. Its really an outdoor job, but for now it is indoors behind a ground level door that faces toward the towers - we dont use that door or the room it is in much.



[This message has been edited by wclark (edited 01-05-2001).]
 

·
Premium Member
Joined
·
7,158 Posts
Did anyon notice WCVB-DT out on Thur night & WCRB (radio) out last night (Friday).


Are the more construction issues going on?


Tim
 

·
Registered
Joined
·
88 Posts
gkoester,

Hi, actually I live in Tewksbury. I use two antennas. One is a UHF yagi type antenna on the roof with a rotor and is non amplified and I also have a simple $2.99 Radio Shack UHF dipole on top of my TV set. The dipole is mounted on a wine bottle. Both work well. Tewksbury is about 20 miles from the towers in Needham. I can receive all boston channels , solid with both antennas. The indoor dipole does very well with signals running from 60 to 94 on the DTC 100 for all stations. The Yagi gets all the stations in Boston and NH 59 and 57. I have found that amplified antennas cause problems, also that bad cable is another problem when dealing with DTV signals. In the case of both the problem is standing or internal reflections in the coax or distortion in the amplifier. Hope this info helps you...


Pat
 

·
Registered
Joined
·
959 Posts
I haven't changed my round dish to the oval one yet, but I'm using a Terk set top antenna to feed my Marquee 8000 projector.

I'm receiving 20.1 30.1 and 42.1 with signal strengths in the low 70's. I'm located in So. Boston.

I can't locate Fox. If I'm getting everything else, shouldn't I be getting Fox also?
 

·
Registered
Joined
·
634 Posts
Jon,

The signals your antenna receives are a mixture of direct line-of-sight and reflections from all kinds of things, thus the term multipath. Ironically, if you're close to the antenna, a lot of the bounced stuff can have a high signal level and drive your system crazy. This can be made worse with an amplified antenna. A really directional antenna with no amplification would probably help CBS, but might have to be reaimed for FOX. I use a DTC100, which has inputs for 2 antennas, and use different antennas for different stations. I don't know if your setup allows this.
 

·
Registered
Joined
·
144 Posts
Jon,


Drop back 3 from your last post and re-read mine. I eliminated a LOT of stuff from my reply but trust me I went thru all the things you are seeing.


My guess is multipath is killing you not lack of signal strength.


I wouldnt trust your Terk to be the equivilant of the Radioshack bow-tie. My experience with Terk antennas is they are poor quality and way overpriced.
 

·
Registered
Joined
·
144 Posts
Gumby,


This is a guess. Since signal numbers on the DTC100 represent quality, not quanity what you may be observing is increases in multipath signals from time to time.


Without a lot of brick and mortar structures around to be the main reflectors for multipath signals the sources are probably hills and other natural features. These do change their dielectric properties according to heat, temperature and precip.


In theory a good directional antenna should reduce these, assuming they are coming from the sides or behind the antenna but even really well designed high gain directional antennas have various side and rear lobes where they are sensitive and based on my own experience so far with yagi and periodic antennas - and OTA DTV - some the models produced dont reject off axis stuff that well.


You might take a look at ch44 and see if you have a lot of multipath (ghosting). Also aiming the antenna to reduce that ghosting on 44 will benefit the DTV channels as well, at least 20 and 30 anyway.
 

·
Registered
Joined
·
144 Posts
Let me preface this by saying I am no expert on this digital reception thing. For that matter we are all pretty green. Some of my knowledge of antennas and RF transmission/reception from my analog days seems to apply to DTV OTA reception but the relative importance of some factors like signal strength and multipath seem to be different so the perfect setup is not necessarily going to be what worked well for analog.


Based on my recent learning it seems that signal quality (absense of multipath interference from the source) is much more important in DTV than in analog. Absolute signal strength and (perhaps) adjacent channel interference is much less important in DTV.


So, the idea of adding electronic gain to an antenna - which was a popular way to improve fringe reception with analog - may not help. In fact it may make matters worse since amplification is indiscriminate and will increase the levels of delayed (miltipath) signals just as much as the early direct signal. On the otherhand, very high directivity antennas with high side and rear rejection should make things better. The problem picking antennas today is that most are specified according to a gain figure and no 3d polar plots of the "gain" are provided - which would give us a good idea of an individual antennas directivity.


Since most of the UHF antennas available are not tuned to a single frequency which would allow quite high directional and gain charateristics, they are broadly tuned to permit fairly uniform "gain" across the UHF TV band. This compromise reduces gain and directivity considerably, essentially allowing more signal in from other directions than the source.


There are ways to improve a broadly tuned antenna in this regard but the easiest 2 solutions to us consumers is to try to find a good directional antenna - for instance the anectdotal info in this forum regarding particular successes with antennas is a good source, and you seem to have chosen one of the recommended antenna - then experimenting with location of the antenna (height as well as where on a lot it is sited). In this case higher may not be better, since it is multipath reduction and not simply signal strength increase you are looking for.


I will give you an example. My bow-tie is really an outdoor antenna. I initially set it up indoors, behind an outside wood basement-level door that generally faced the direction of the towers. After a bit of turning, I was able to get all the DTV stations with very high and stable quality numbers. This was to be a temporary setup until I could go outside and site it on the roof. I moved the antenna last weekend to the site on the roof of my previous 2 antennas and what I found was a significant reduction in the stability of the quality numbers on DTV and more visble ghosting on 44 analog. So the antenna is back in the basement for now. Obviously the low height and earth/masonry features that the antenna "sees" from the basement position are of more help than harm and getting it up where it is really line-of-site to the towers is also making it more exposed to some reflections. Of course the more exposed downlead from the rooftop could be contributing but it is quad shielded RG-6 which is about as good as it gets so I have to live with whatever it is capable of.


Good luck "tuning" your setup.
 
1 - 20 of 274 Posts
Status
Not open for further replies.
Top