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Boston, MA - OTA - Page 344

post #10291 of 10633
Quote:
Originally Posted by Channel99 View Post

WBZ, WSBK, and WGBX are all back on the air now.

.....and WCVB channel 5.1 is back to full power as I am now receiving it OTA in Fall River. I was not receiving it at all when they were transmitting with their backup transmitter/antenna at reduced power.

On another matter WGBH OTA channels 2.1 and 2.2 are now (as of 17:00 today) off the air. I wonder if this is related at all to the other recent outages or just coincidental.

Got my answer from the Boston Globe article: "At 1 pm Tuesday, engineers at the affected stations briefly shut down WGBH, then moved its signal to the backup antenna being used by WCVB. Then WCVB, WSBK, WBZ and WGBX all began broadcasting from the WGBH antenna." Apparently I am too far away from the backup antenna to receive WGBH OTA.
post #10292 of 10633
Lisa Hughes on Channel 4 during the 5pm broadcast

Quote:


"Tonight we're glad to report that WBZ and myTV38 are once again broadcasting over the air, we had a transmission problem on sunday night and crews have been working to fix it ever since. in the mean time we thank WGBH and WCVB for letting us use their antenna's temporarily while those repairs were underway. and we also want to thank you especially those of you who got cut off during the masters for your patience."
post #10293 of 10633
Apologies for the delayed reponse. a) We were a little busy, and b) inevitably when there's a big story going on, my AVSForum notifications stop coming.

As you know, we suffered a failure in our shared antenna on Sunday evening. At the Needham site, we have a 100-foot top-mounted stick, housing two separate antennas. Channels 4, 5, 38, and 44 transmit from the upper antenna, and channel 2 from the lower. In earlier days, analog channels 38 and 44 also used the lower antenna, but since the analog shutdown in 2009 channel 2 has been the only station on it.

The failure occurred in the upper antenna and knocked off all of the stations using it. Channel 2 was unaffected. Shortly after, channel 5 switched to a low-power standby antenna. That left channels 4, 38, and 44 completely dark.

We have three 8 transmission lines running up the tower, one each for the upper and lower antennas, and one spare. We initially cut the spare line into use, in case the problem was with the top antenna's line, but that turned out not to be the case. In the meantime, an RF consultant arrived on site and took measurements with a vector network analyzer, which revealed the problem to be at the base of the upper antenna.

This afternoon we switched channel 2 into channel 5's standby antenna, which freed up the lower antenna, and we are now feeding other stations into it. Channel 2's generosity in operating at low power while permanent repairs proceed should not be underappreciated, as it is only because of that generosity that we are on the air at all.

A word here about why it takes so long to effect repairs. The transmission lines consist of copper pipes, 20 feet long and 8-3/16 in diameter, each containing an inner copper pipe, 3" in diameter, with the inner and outer separated by Teflon insulators. The sections are joined with nuts and bolts at flanges at each end. Connecting, moving, and mounting of these lines is heavy, exacting work. Now think about doing it when the pipe is vertical and you are balanced on a tower 1,100 feet in the air. It's slow. Real slow.

We expect the final repairs to take a while. Working on the antenna is especially difficult, as the panels that surround the problematic part must be removed and the part tested and brought to the ground, all while hanging from rigging almost ΒΌ mile up.

We do have an elevator on the tower, but it only goes up to the 850-foot level. At that point the tower reduces in width from 12 feet across to 7 feet, so tower workers have to climb the top 250 feet.

By the way, Mike Fitzpatrick is dead-on correct with his comments. We treat the over-the-air systems with as high a priority as everything else. Every transmitter engineer and his immediate superior (and I) reported to the site Easter Sunday evening as quickly as they could, and didn't leave until late that night. Yesterday I was at the site from 6:30am until 11:00pm, and then back again early this morning. In addition, representatives from all of the stations, their parent companies, and our consultants and vendors have been intensely involved and working continuously to resolve this. This was a very big deal to every station involved.

For Bill Bibeau and others interested, see these two sites for some pictures of the installation: http://www.fybush.com/sites/2004/site-040723.html and http://www.necrat.us/bztower.html. The first site has quite a few pictures from back in the analog days; most of that stuff is gone.

I'll be happy to provide additional details for the geeks amongst us. Just ask...
post #10294 of 10633
R.Y.,

Thanks for posting the summary, and for the effective/safe repairs, as well as for an acrophobic Smith-Chart flashback.
post #10295 of 10633
R. Y.

Thanks for the update. Interesting description of the tower.

I did not realize broadcasters use wideband antennas. Not having though about it much I just assumed the antennas are cut to a particular channel and each transmitter feeds a dedicated antenna.

How do you patch in the spare coax? I assume this requires some kind of mechanical reconfiguration not just energizing a relay.
post #10296 of 10633
Thank you for the heads up on the situation there at the antenna/transmitter site. I didn't realize that all the stations were using the same antenna. Things have changed since I first got into broadcasting back in 1968 at the old WICE, 1290 kHz. in Providence, RI. The Chief engineer there eventually went over to WJAR TV in Providence. Unfortunately he died a few years later, and I left broadcasting for a time before returning years later.

The situation reminds me of the time Hurricane Isabel hit the Hampton Roads area of Virginia. I was at WVEC Channel 13 in Norfolk. We were on our generator for 6 days. The bulk of that time I spent at out transmitter site keeping the transmitters on the air....both our analog as well as our DT transmitter. This was before the transition to all DT. It meant some long days!

The pictures of the site and information were interesting to say the least. Thanks for the information as well congratulations for a job well done. I'm am sure as time goes on, the final work will only help things. Have a good day and enjoy some well deserved time off.
post #10297 of 10633
Quote:
Originally Posted by Tschmidt View Post

R. Y.

Thanks for the update. Interesting description of the tower.

I did not realize broadcasters use wideband antennas. Not having though about it much I just assumed the antennas are cut to a particular channel and each transmitter feeds a dedicated antenna.

How do you patch in the spare coax? I assume this requires some kind of mechanical reconfiguration not just energizing a relay.

At the base, it is just a push of a button to move a waveguide switch. At the top of the tower, the workers have to drag up a 3-1/2 foot piece of 8" transmission line (about 25 pounds) and an 8" elbow (about 35 pounds). Then they have to disconnect one line and connect the pieces to the other. Takes about two hours, not counting the trip to the top.
post #10298 of 10633
Channel 4, 5, 38, and 44 are back on the air. However, PBS' WGBH Channel 2 Boston (virtual channels 2-1 and 2-2) went off the air this afternoon and is still off. No announcement provided either. All these stations transmit from the same antenna tower in Needham, Mass. Presume it is related to the repairs?

Thanks for the details about the Sunday night transmission failure. None of the local radio or TV stations would report the story leaving viewers mystified in 4 states and 2 countries. There has been a news black-out. WBZ, and only WBZ, put a terse notice about 'technical difficulty' on their website a day later. Clearly, none of these stations have incorporated social media communication into their emergency plans. That is disheartening.
post #10299 of 10633
OMG !!! Are you kidding me!! These guys worked their butts off to restore pictures to you and me. I am lucky enough to receive Providence off air.WGBH didn't have to give them their antenna! I have Directv no locals.I rely on off air. Thank you VERY much to the engineers!
post #10300 of 10633
Quote:
Originally Posted by RHetor96 View Post

Channel 4, 5, 38, and 44 are back on the air. However, PBS' WGBH Channel 2 Boston (virtual channels 2-1 and 2-2) went off the air this afternoon and is still off. No announcement provided either. All these stations transmit from the same antenna tower in Needham, Mass. Presume it is related to the repairs?

Thanks for the details about the Sunday night transmission failure. None of the local radio or TV stations would report the story leaving viewers mystified in 4 states and 2 countries. There has been a news black-out. WBZ, and only WBZ, put a terse notice about 'technical difficulty' on their website a day later. Clearly, none of these stations have incorporated social media communication into their emergency plans. That is disheartening.

http://www.wgbh.org/articles/Work-Ma...-2-Signal-5979 WGBH's story about the outages

http://www.thebostonchannel.com/news...64/detail.html
WCVB's story about it.

http://boston.cbslocal.com/2012/04/0...-difficulties/ WBZ's story about it.

http://www.boston.com/Boston/busines...HxM/index.html
The Boston Globe's story...

So they all have reported it, to the detail a standard viewer would need to know.

WGBH-TV is on the air, just at a very reduced signal from the auxiliary ant.
(Please read the above posts for more information...)
post #10301 of 10633
WGBH shifted to an aux. antenna with lesser coverage and allowed four off-the-air stations to use its main antenna to resume broadcasting after the failure of their combined main antenna. Why can't WGBH be added as a sub-channel onto one of those four stations to recoup lost coverage while this crisis is resolved? Obvioulsy the FCC would have to waive non-commercial restrictions, but that should be a slam dunk. There would also be resolution issues, and is that worth the trade off during this emergency??
post #10302 of 10633
The easy answer would be to accelerate the move of World from 44-2 to 2-2 and temporarily place WGBH on 44-2.

- Trip
post #10303 of 10633
Well into day 6 now and WGBH 2 is still off air and WGBH hasn't updated anything about the situation on their web site since Monday.

Do they even care at this point? And wouldn't it just be easier to build a new tower? That's only semi-sarcastic. Since the conversion to DTV I have lost count of the number of off-air incidents that have happened with the two local towers. But this one is certainly on record as being the longest.

Why is this equipment so much more prone to failure than the former analog transmission equipment?
post #10304 of 10633
Quote:
Originally Posted by Rickajho View Post

Well into day 6 now and WGBH 2 is still off air and WGBH hasn't updated anything about the situation on their web site since Monday.

The low power WGBH signal is OK here in Southern NH.

I share your frustration with the lack of information. The first thing I did when this occurred was go to the various station web sites, then I came here. If if was not for this forum I doubt I would have ever figured out what was going on.
post #10305 of 10633
Quote:
Originally Posted by Rickajho View Post

Well into day 6 now and WGBH 2 is still off air and WGBH hasn't updated anything about the situation on their web site since Monday.

Do they even care at this point? And wouldn't it just be easier to build a new tower? That's only semi-sarcastic. Since the conversion to DTV I have lost count of the number of off-air incidents that have happened with the two local towers. But this one is certainly on record as being the longest.

Why is this equipment so much more prone to failure than the former analog transmission equipment?

Rick, with all due respect, did you even read the other pages of this thread before posting? WGBH is NOT off the air, they are at reduced power for the time being. So if you live outside the coverage area , you won't see the signal.

And of course they care. They have been working on the issues with the transmission system since it failed. Why do you people assume that this is being passed off? I strongly suggest you go back and read Mr. Yankowitz's post about it. It will explain a lot to you.

As far as the failure rate, from what I know, this is the only large outage they have had since running at high power. The combined DTV room definitely has more going for it, because of the power level being used. With analog TV, the power levels were in the low 50kW range. With DTV, the power levels are closer to 500kW. With 10x the power level there is a greater risk of RF conditions like a "burn out" or other catastrophic failure, but the risk is small, and what happened with the antenna systems here, is unusual.

If you're seeing a constant "outage" rate, there may be a issue with your reception/receiver. Remember with DTV, there is no "weak fuzzy signal". Due to the Cliff Affect, your signal is there or it isn't. If you happen to be on the edge of the WGBH signal, which is lower than WBZ or WCVB, during normal conditions, you can have environmental conditions cause the signal to drop out,
post #10306 of 10633
In case you missed it, WGBH has posted the following update on their website:
Update, April 13, 8:30 p.m.

The over-the-air Channel 2 signal is continuing to experience reduced strength due to the mechanical situation at the Needham Tower. Unfortunately, the damage is significant and will require a multi-step repair process being performed by the tower owner and is out of our control as a tenant.

At this point, the signal is not expected to be restored to full strength through the coming week. We apologize for any inconvenience this may cause to our viewers and will update this situation as more information becomes available.
I'd like to add my thanks to all the engineers who, I'm sure, are working as hard as they can to get WGBH back to full strength.

I'm just nortwest of Milford NH, and can't get WBGH at present. I feel lucky I can get both WGBX and WENH, so probably won't miss too much!

Paul
post #10307 of 10633
Quote:
Originally Posted by Mr.H View Post

In case you missed it, WGBH has posted the following update
Paul

Glad they posted the info. How did you ever find it?

Even after you posted the link I tried to looking for the info their site rather then clicking the link and couldn't find it. Looked in news, regional, TV schedule, Reception problem FAQ, etc.
post #10308 of 10633
Anyone else not getting 2 4 5 44 today?
I tried at ~ 300PM and they are still off now at ~600PM
maybe they are transferring back to the regular tower?
post #10309 of 10633
Quote:
Originally Posted by alczervik View Post

Anyone else not getting 2 4 5 44 today?
I tried at ~ 300PM and they are still off now at ~600PM
maybe they are transferring back to the regular tower?

Ayup.

(Except for WCVB-5, as I'm in the FCC-created Venn diagram-like co-channel overlap where neither station can come in. )
post #10310 of 10633
All four of the affected stations (4, 5, 38, and 44) transferred to a temporary, lower power antenna today while climbers worked on the damaged equipment at the top of the tower. (Channel 2 remains at low power operation on a different antenna and did not change operation today). Everything is back to (semi)-normal now.

Work is ongoing, and we will be repeating this again in future days until all repairs are complete. Unfortunately, right now I cannot make any predictions on when that will be, as the full extent of the damage is not yet known.

Please bear in mind the workers are suspended almost 1/4 mile in the air, and while the view is terrific, conditions are not conducive to fast work.
post #10311 of 10633
Quote:
Originally Posted by RYankowitz View Post

All four of the affected stations (4, 5, 38, and 44) transferred to a temporary, lower power antenna today while climbers worked on the damaged equipment at the top of the tower. (Channel 2 remains at low power operation on a different antenna and did not change operation today). Everything is back to (semi)-normal now.

Work is ongoing, and we will be repeating this again in future days until all repairs are complete. Unfortunately, right now I cannot make any predictions on when that will be, as the full extent of the damage is not yet known.

Please bear in mind the workers are suspended almost 1/4 mile in the air, and while the view is terrific, conditions are not conducive to fast work.

Rob,

Those guys are made of steel. I get nervous going on an 8 ft ladder. I was finally over it 10 yrs ago until the ladder collapsed in the 8ft mode on me last year. I can see where this would take a few weeks, start to finish, weather permitting. Great job.

Dominic
post #10312 of 10633
Thank you for the inside update rob,

God bless those men, it must be even worse when its windy and or cold
post #10313 of 10633
Tower Guys are some of the most underappreciated workers in the business. The entire wireless industry would not exist without the work of tower riggers. Same with basically all communications syetems. These guys are worth their weight in gold, especially to us broadcasters. I have a very fine appreciation for the work they do.
post #10314 of 10633
As of today, WGBH world is now on 2.2.
post #10315 of 10633
Quote:
Originally Posted by W1KNE View Post

Tower Guys are some of the most underappreciated workers in the business. The entire wireless industry would not exist without the work of tower riggers. Same with basically all communications syetems. These guys are worth their weight in gold, especially to us broadcasters. I have a very fine appreciation for the work they do.

I have to echo your statement Mike! We used to use our elevator to go up to the 900' point on our tower and often did the bulb replacements up to that point....one engineer in particular was more agile than I was or a couple of us older guys. I remember going up to the 900 foot platform where I stayed and watch one of the professional tower guys climb up to the top, in the dark (just moonlight) to replace the top bulb which had burned out. (We shut the transmitter down while he was up there which was why it was done at night) There was not enough money in the world that would have made me go do that! Those guys have nerves of steel!
post #10316 of 10633
Quote:
Originally Posted by ssetta View Post

As of today, WGBH world is now on 2.2.

I guess it is somehow related and not too off-topic:
I purchased a new HD car radio at the beginning of the antenna issues. I could not receive WGBH radio HD and sub-channels. I tried this AM and it is coming in crystal clear.
Was WGBH HD radio disabled to make way for the changes last week?

Mike C.
post #10317 of 10633
Quote:
Originally Posted by mcocorochio View Post

I guess it is somehow related and not too off-topic:
I purchased a new HD car radio at the beginning of the antenna issues. I could not receive WGBH radio HD and sub-channels. I tried this AM and it is coming in crystal clear.
Was WGBH HD radio disabled to make way for the changes last week?

Mike C.

That would be a no. WGBH-FM transmits from the top of Blue Hill in Canton. It is not on the tower affected by this work.
post #10318 of 10633
WGBH has posted a further update on their website.. it reads:
April 18, 2012

On April 8 there was a major failure in the combined transmission antenna at the Needham tower site that affected WGBH 2, WGBX 44our multicast services World, Create, and Kidsas well as WBZ, WCVB, and WSBK, which all share the transmitter. Crews were immediately dispatched to the tower and they made emergency repairs, which allowed these stations to return to the air, though at a diminished broadcast coverage area for both Channel 44 and Channel 2 and for some cable subscribers.

As of Wednesday, April 18, the upper antenna must be removed due to the extensive damage to the components. The parts needed must be manufactured, installed, and then tested for a complete repair to be accomplished, which may take up to a month.

The repair effort requires careful coordination between all affected stations, the tower owner, and the tower crew. And because the tower is 1,200 feet high, the work is dangerous and complex.

We understand how frustrating it is to be without the WGBH service, but we are doing everything possible to see that repairs are made as quickly as possible, with consideration for the safety of the work crews.

If you are not currently able to receive one or more of the stations, please try rescanning your channels, which may allow you to reacquire the signal if you are within the broadcast range. We'll update our website as soon as more details come in from the tower site.

We sincerely appreciate your patience and support.

Viewers who have any questions or concerns can contact us here.

Looks like it could be upwards of a month before things are back to normal!
The link to this update is on their homepage in the section labeled "Featured"

Paul.
post #10319 of 10633
Quote:
Originally Posted by Mr.H View Post

Looks like it could be upwards of a month before things are back to normal!

Thanks for the update.

There may be a silver lining for me once the antenna is repaired. 44 has always been spotty and 38 is an almost constant no show. Hopefully the repaired antenna will improve reception in Southern NH. TVfool models signal strength for 38 and 44 higher than other Boston stations we experience much better reception. Perhaps the antenna has been out of spec for a long time.

Much to my surprise low power WGBH has been is pretty stable.
post #10320 of 10633
Wow look at some of the vile comments in the comment section. Must be nice to have such a faithful and understanding audience.
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