SBE Chapter 47
What You Missed - Past Meeting Notes
SBE Chapter 47, Los Angeles
Here is the summary of today's(11/9/04) Los Angeles Chapter 47 SBE meeting, regarding electrical power on Mt Wilson:
Ben Pederson is no longer with the project mostly due to internal company shuffling. However, he remains THE resource on the subject even within SCE (Southern California Edison). If you have his card, the only thing currently accurate besides his name is his e-mail address and cell phone number.
SCE started providing power to Mount Wilson in 1914 for the hotel that was built there. The system was upgraded about 1948 when broadcasters started putting stations on the mountain. What started out as a single substation and line has grown to five substations each serving part of the maintain top. The main feed, "video 16 KV feed", starts at the Eaton substation in Pasadena and goes pretty much North to Wilson. It starts overhead on square towers, then drops to an underground feed. I think this transition is made at "the blockhouse" which I think is the concrete building where the Mt Harvard road splits from the Old Mt Wilson Toll Road. From there the feed is underground. It started with two parallel circuits with one as a standby, but as the Wilson load increased, they put the two circuits together. Neither one can handle the current load by itself. Mt Harvard is tied into the circuit at the blockhouse. Since the transformers at the Mt Wilson substation have automatic adjusting taps, Mt Harvard suffers from poor voltage regulation being affected by its load, the effect of the substation taps adjusting and whatever voltage variations happen at the Eaton end.
The second feed, "Chilao feed", to Mt Wilson starts at the Gould yard above La Crescenta and continues up the Angeles Crest Highway. This feed normally carries the power only for the few cabins along the Highway and cannot handle the entire current Wilson load. This feed is all overhead and was maxed out, as far as Mt Wilson is concerned, in 1985.
The Mt Wilson 16 KV load was running 16A in 1988, but it currently running 34A. The estimated future load is 290A, but the Eaton lines are only rated at 210A. Mount Wilson power DOES, at this point, have single points of failure. Improving the situation is a $10 Million project and was a tough sell because the investment will not be recouped from the Mt Wilson revenues. In other words, its being subsidized by the rest of the ratepayers. Some media clout was used to keep this project funded. SCE does have the capability for backup generation at Wilson, but that will take about half a day to get installed (to cover those without their own generation). They estimate that a serious failure of a circuit may take up to two weeks to get repaired, partly because of NFS involvement and rules.
Phase 1 of the project is to upgrade the Chilao feed from 16 KV to 33 KV which would quadruple the amount of power it can provide. Once this is complete, it can function as a full backup for the Eaton feed. This phase is fully engineered and procured, but waiting for negotiations with the NFS about when and where SCE can work. This work will be done almost entirely with air access, dropping equipment and personnel on each tower. It can be done hot, but will go much faster if done cold. Since the normal load is only cabins, its most likely going to be done cold.
Phase 2 is to upgrade the Eaton Feed. Part of this feed is gas-filled cables and SCE has only one person capable of splicing it. Anything else in the system, they have at least 50 people capable of splicing. This is a serious construction project and will require that feed to be down for a while. At this point, Wilson will be fed from the Chilao feed.
Phase 3 is to upgrade the current distribution ON the mountain from 4160V to 16 KV feeds to the customer. Since this is an unusual configuration, the equipment will be smaller than what is normally available and so most of it is special order stuff. This phase will entail replacing all the distribution wire on the mountain as well as the customer transformers. This will involve digging things up.
SCE regularly maintains spares of everything in the system, even the special order equipment. It is stored as close as possible to the point of use. In the case of much of the infrastructure at Mt Wilson, it is so old that it can't be replaced. That equipment will be upgraded to currently used equipment when it fails.
Phase 1 will be transparent to Mt Wilson customers, but Phases 2 and 3 will not. The current estimated completion date for the entire project is 2008.
The outage we had 3 or 4 months ago did not involve Mt Wilson, other than losing its power. There was a problem on a 500 KV line elsewhere in the system that tripped a lot of stuff off. Some of that stuff was on Mt Wilson.
By Jim Sensenbach, Engineering
Univision Radio/LA, formerly Hispanic Broadcasting Corp./LA
Lunch Meeting: Al Jason of Dielectic presented a paper titled "Maximizing Your Stations Signal". The discussion was in regard to FM antennas and mounting criteria with good Q&A afterward. Al also handed out some doorprizes to those who asked good questions. Chapter Business began with an announcement by Chapter Chairman that the 530KHz TIS (Travelers Information Service) transmitter serving LAX (Los Angeles International Airport) has been granted a power increase, fulltime, to 100 Watts. This is not normally allowed under FCC Rules for TIS operations. It was noted that there may be interference to listeners of 540 KHz from this granting. There was discussion of setting up a chapter sponsored Networking Seminar that will lead to attendees being prepared to take the CBNT Certification Exam from the SBE. There will be a cost for this all-day seminar. Date/Time TBD. There will be no Chapter 47 Monthly Meeting in April due to the NAB convention in Las Vegas. We normally take off April because of NAB.
Dinner Meeting: Buck Walters of Broadcasters General Store presented Kirk Harnack of Telos Systems to present the Telos LiveWire system. Kirk also led a discussion of the new Telos Xtream and Xport Zephyr units. Thanks to Buck and BGS for covering our Dinner. Chapter Business included a motion and acceptance of the motion to sponsor a donation of $1000 to the James Schoelfield Family Relief Fund. Jim is a chief engineer at WAMC-Albany, NY, who lost part of his family and his house in a wintertime fire. See http://www.radioink.com/headlineentry.asp?hid=118703&pt=inkheadlines for more info. Also decided was to skip the April Chapter meeting due to NAB.
Lunch Meeting: Dane Butcher and Jim Latimer from Symetrix Audio presented their new SymNet Audio Matrix system. Chapter business included report of an engineer in the New England area, James Scholefield, chief engineer at WAMC-Albany, NY, who lost his family and home to fire and if the chapter should donate funds to his needs.
Dinner Meeting: No official program presenter tonight.
We had an open discussion of all things technical to broadcast engineers in
attendance. The group discussed DAB
progress starting with a report on putting DAB onto KTNQ, a 50KW DA5 diplexed
with another 50KW DA5. There was some discussion about AM becoming more of
a local service with the loss of skywave coverage in DAB. The comment
about the possibility of including EAS into the DAB datastream and getting it
off our programming stream led to a discussion of recent problems with EAS in LA
and elsewhere. We started with the premise that the best time to think
about EAS problems and solutions was in between crises. We discussed how,
as engineers, we are used to dealing with backups and other disaster related
issues. We need to use that experience to make our entire operation
disaster proof. We need to think of disasters that affect only our own
station(s) and figure how to maintain logs, sales, and billing. Feeding
our families depends on maintaining the cash flow!
I guess you had to be there. The discussion really had a good flow to it. Dick Rudman was there to facilitate the EAS discussion. See you later! - Chapter Chairman Jim Sensenbach
Lunch Meeting: Todays meeting was presented by Jay Brentlinger, Greg Ogonowski and Steve Gordoni of ORBAN. Jay brought the Orban Road show RV and trailer just packed full of Orban gear. Chapter business included a discussion of new BAS Rules and frequency coordination issues. Also discussed were ways to monitor off-air signals of digital, high-latency, broadcast signals in our control rooms.
Dinner Meeting: John Paoli of KFI, Clear Channel, and our local LECC for EAS discusses AMBER Alerts as related to EAS and local implementation. CHP, County of LA and State of CA officials were present to discuss AMBER alerts in California and Southern California (Los Angeles area). Chapter Business included discussion of Part 74 BAS licensing procedures that now require coordination and notification. Also a slight discussion of 2 GHZ conversion for those licensees. Almost 40 people in attendance.
Lunch Meeting: Local discussion of EAS presented by LA County broadcaster John Paoli, KFI, Clear Channel and a discussion of the SCFCC (Southern California Frequency Coordinating Committee) presented by Howard Fine. Chapter business included discussion of donation of $400 to Dave Biondi at Broadcast.net to help with costs of replacing his router that connects many SBE chapter websites, including ours, to the Internet. We voted to let the Chapter Chairman to offer up to $400. There were no objections.
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