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By Paul Thurst, on August 11th, 2010
 Harris Dexstar Exciter I was reading several very interesting IBOC related articles and posts today. First of all, if Tom Ray, engineer from WOR and strong proponent of AM HD Radio seems a little reticent lately, well, perhaps this explains a few things:
Tom Ray finds himself discouraged based on a Ford shopping experience.
I’d recommend reading the whole thing, however, here are some of the highlights:
- Fear of HD radio going the way of FM Quad and AM Stereo
- Asks for a HD radio at the Ford dealership, no one can figure out what HD radio is
- WOR news director states “HD radio sucks” then asks to have his car radio programmed for analog only
- HD radio less known than Apple iPad product
- Joe consumer would not be able to make heads or tails out of it.
RBR has more here.
It is telling that one of the most vocal proponents of IBOC would publish an article such as this. It seems to be diametrically opposed to the latest press release from iBiquity insisting all is well, never fear, etc. Perhaps it is meant to spur things on, rally the troops as it were.
The second item I found very interesting, Paul Riismandel from Radio Survivor fools around with a Sony XDRF1 HD receiver. He posts a great deal of information about his experience. It is a good read. To summarize some of the points of this story:
- It is difficult to receive HD radio signals in the Chicago Suburbs.
- When FM HD radio is in use, it is difficult to tell the difference in sound quality between the analog and the IBOC programming
- Secondary channels have low bit rates and are not suitable for listening to music
Finally, Radio World, again, states that after six months 86 FM stations have completed the allowed IBOC power upgrade. That information is from the NAB. I cannot find any official FCC information regarding this, I would like to know if any of those 86 stations are around here. By the way, 86 out of 1,524 stations represents 6 percent of existing IBOC stations have upgraded. That makes 0.9 percent of the total number of FM stations licensed to the US running -14dBc IBOC carriers.
I will allow the reader to draw his/her own conclusions.
By Paul Thurst, on August 10th, 2010
 If you have ever wondered about those ubiquitous NOAA all hazards radio (formerly National Weather Service radio) station, wonder no more. These stations transmit on one of five frequencies in the 162 mhz band with power ranges between 250 and 1,000 watts. There are over 1,000 transmitters scattered throughout the country including outlaying territories like American Samoa, Guam, Northern Marianas, Virgin Islands and Puerto Rico.
The original 1958 plan was for these stations to transmit Aviation and Marine weather forecasts. The system was expanded for use by the general public in the early sixties. Since that time, it has been slowly expanding until, with the most recent survey concluding that NOAA weather radio station can be received by 95% of the US population.
One of those stations in my neck of the woods is due for a transmitter upgrade. WXL-37 uses two Scientific Radio Systems SR-416P transmitters, as a main and a standby. The programming audio comes from the NWS office in Albany, New York, via TELCO line. The old transmitters are tube type made by in 1976. They are reliable transmitters, however, after 34 years of continous use, they are getting a little tired. They are also big and bulky and since Scientific Radio Systems went out of business, not supported.
This year, NOAA is replacing these transmitters with a Nautel NG1000. I have worked with Nautel’s military grade transmitters before and found them to be extremely rugged. Those transmitters are what the original AMPFET design was based on. Nautel is not the only vendor that NOAA is using however, others include Armstrong Transmitters and Crown Broadcast.
 NOAA Scientific Radio Systems SR416P VHF transmitters The Nautel NG1000 is a little thing, taking up about half an equipment rack with an outboard cavity filter and dummy load. There are two drawers, a controller an antenna switch and a remote control. Each drawer is it’s own 1 KW transmitter. The GUI is a on a laptop, which is what I prefer. If there must be some sort of computer driven GUI, then make it removable, so that when lightning strikes the 1,000 foot steel lightning rod 25 feet away, it doesn’t get blown up. Each transmitter is connected to a 30 AMP 240 Volt breaker via a 4 prong twist lock plug.
 Nautel NG1000 NOAA transmitter The antenna for this station near the middle of this 1,000 foot tower, thus the station gets excellent coverage with a TPO of 1,000 watts.
 American Tower site, Highland, NY On a related side note, the computer synthesized voices normally heard on NOAA stations took several years to evolve. Remembering when this began back in the mid 1990′s with “Paul.” Several years later, “Craig” and “Donna” were introduced. Finally, “Tom,” which is able to change voice inflections for emphasis. When I was in the Coast Guard, we did high seas synopsis and forecast on HF without aide of computers. At times, especially during typhoon season, it got a little busy in the weather broadcast position. There are advantages and disadvantages to both methods. Personally, I’d rather hear a human voice, especially in a crisis.
By Paul Thurst, on August 5th, 2010
As broadcasters, we don’t really hear that much about ceramic power vacuum tubes these days, as more and more broadcast transmitters migrate to solid state devices. Once upon a time, however, power tubes where the engine that drove the entire operation. Tubes had to be budgeted for, stocked, rotated and replaced on a regular schedule. Some of those dern things were expensive too.
Take the 4CX35,000A which was used in the Harris MW50 transmitters. The transmitter used two of these tubes, one in the RF section and one it the modulator. As I recall, new tubes cost somewhere north of $8,000.00 each from EIMAC. Plus, in the A models there were two 4CX1500A driver tubes. All of which could add up to an expensive maintenance cost every two years or so.
The next best option was to buy rebuilt tubes. Rebuilt tubes were about half the cost of brand new ones. Some people complain that rebuilds don’t last as long, or only last half as long as the new tubes. I never found that to be the case. I often found other factors effected tube life far greater, such as filament voltage management, cooling and by extension, cleanliness.
I can say I never had a warranty issue with ECONCO tubes. I cannot say that about EIMAC, as during the late 90′s and early 00′s (or whatever you call that decade) I had several brand new 4CX3500 tubes that were bad right out of the box. These days, ECONCO and EIMAC are both owned by CPI.
I spoke with John Canevari from ECONCO who had a lot of information. For example, as the tube ages, the filament gets more flexible, not less. Most ceramic power tubes use a carbonized tungsten filament containing some small amount of thorium. As the tube ages, the filament can no longer boil off enough electrons and the emission begins to drop off. That is the normal end of life for a power tube. Occasionally, some catastrophic failure will occur.
There are many steps in the rebuilding process:
- Dud is received from the field, the serial number is recorded and the tube is tested in.
- The tube is prepped by sand blasting the sealing rings
- It is opened
- Filament is replaced. In 60-70% of the cases, the grid is replaced. In those tubes that have a screen assembly, 20-60% of those will be replaced.
- Interior of the tube is cleaned
- Tube is resealed and tested for leaks with a gas spectrometer
- Tube is placed on the vacuum machine. Tubes are evacuated hot, smaller tubes take 12 to 24 hours, very large tubes can take up to one week.
- The tube is nipped off of the vacuum while still hot. When the tube is fully cooled the vacuum scale is normally around 10-12
- Exterior of tube is cleaned and replated. Silver for tubes that are socketed and Nickel for tubes that have leads.
- Tube is retested to manufacture’s original specification or greater.
After that, the tube is sent back to its owner or returned to stock. John mentioned that they are very proud of there vacuum tube processing machines, so I asked if he could send along a picture. They certainly look impressive to me, too:
 Vacuum tube processing machine, photo courtesy of ECONCO Not exactly sure which tube type these are, but they sure to look like 4CX15,000:
 Vacuum pump working on rebuilt ceramic power tubes, photo courtesy ECONCO Econco has been in business since 1968 and rebuilds about 600-1,000 tubes per month. In the past, broadcasters used most of the larger tube types. However, with the majority of broadcast transmitters shifting to solid state, other markets have opened up such as industrial heating, military, research and medical equipment.
By Paul Thurst, on August 4th, 2010
I found this interesting article in Inside Radio: FCC simplifies complaint process.
This is part of the “Reboot FCC” initiative which started many months ago. While I applaud the FCC acknowledgement that they are essentially a slow, plodding government bureaucracy, saying something about it and doing something about it are two different things.
The Consumer Help Center is a website where the public can complain about such things as junk faxes, telemarketers, TELCO billing issues, ISPs, indecent language and a whole host of other topics.
My question is, what happens to the complaint, once it is received? I’d like to hear if anyone has tried this and what the results were. Perhaps they will include a section for reporting IBOC interference on the broadcast band.
By Paul Thurst, on August 2nd, 2010
This doesn’t have much to do about radio, other than the fact that I think they are trying to make Rush Limbaugh’s head explode:
Putting the question of marijuana legalization on state ballots in 2012 may be one of the most effective ways for a dispirited Democratic Party to get reluctant voters out to the polls.
The rest of the story here. If they are counting on pot heads to vote for them, they are going to have to start speaking very slowly, repeating themselves a lot and using words like spleef, dude and bogart.
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Axiom
Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof; or abridging the freedom of speech, or of the press; or the right of the people peaceably to assemble, and to petition the Government for a redress of grievances.
~1st amendment to the United States Constitution
Any society that would give up a little liberty to gain a little security will deserve neither and lose both.
~Benjamin Franklin
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~Alan Weiner
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~Universal Declaration Of Human Rights, Article 19
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Heard in the clear