We are currently installing this sweet little transmitter:
Nautel NV-5 FM transmitter
Like its big brother, the NV-40 at WVPS, the NV-5 is a very cool transmitter. I am a born skeptic, things like touchscreen displays tend to make me a little nervous, especially on a transmitter connected to a 350 feet tall steel tower right next to the transmitter building. That is the one major difference between WVPS and this site; at Mount Mansfield there are many things between the transmitter and antenna, but in this place, not so much. Even so, Nautel makes a good product, so troubles are not expected.
The ground strap, AC power, remote control, and composite audio connections were all made without difficulty. The result, new transmitter on the air:
Nautel NV-5 FM transmitter GUI
This unit is analog only, but the information on the spectral display is still useful. The GUI uses Linux with a touch screen, which is a neat feature.
Nautel NV-5 FM transmitter controller board
In case the front panel GUI goes out, all transmitter controls can be accessed via push buttons on the remote control interface, which is the small board to the right. The main controller board is on the left.
Aside from everything else, we have been working at WSBS, Great Barrington, MA installing a new Audioarts Air-4 console. WSBS is a small AM station (860 KHz, 2,500 watts day, 4 watts night) serving the Great Barrington area. They also have a 35-watt FM translator (W231AK) on 94.1 MHz which is highly directional. During the day, the AM station has a much better signal than the translator. After dark, the translator covers the downtown area fairly well. WSBS has been on the air since December 24th, 1957 (Happy 55th anniversary!), broadcasting from a non-directional tower just east of town on US Route 7.
The format could be termed full service, in the old tradition. Music, professional sports, local news, network news, and weather with coverage of special events like election night and so on. The station does local very well, and as such, is profitable and has a great community presence.
WSBS control room console
The air studio console was this rather tired-out Broadcast Audio unit from the early 1980s. It had certainly served its station well, but change was in the air, so to speak. Actually, we were getting worried about continuing to service this unit, as parts had become scarce about ten years ago.
New WSBS control room console
Thus, we moved the air studio to the production room temporarily and removed all the old equipment and furniture. We installed an Audioarts AIR-4, which is a pretty cool little console. The AIR-4 has four built in microphone preamps, a telco mix minus feed, two program busses selectable VU meters and so on. The control room rebuild project included a new counter top, adding extra microphones, headphone amplifiers, cleaning up wiring rat’s nests, installing new monitor antennas, rewiring a good bit of the rack room and so forth.
RE-20
It was a little more involved than we first thought, however, it came out pretty well:
WSBS Great Barrington, MA control room
The carpenter will be back next week, after Christmas to install the sides on the studio furniture under the counter top. It is a small operation in a small market in Western Massachusetts, but they have a real, live station staff including two news reporters. Hey, what a concept! To be honest with you, it is a joy all its own to work at a real radio station, if only for a short while.
After extensive testing of Both HD Radio and DRM, the Secretary of the Ministry of Communications Electronic Communications, Genildo Lins, said the tests of the two technologies have had poor results, especially high-power FM . The testing demonstrated the digital signal coverage is approximately 70% of the current analog signal. “The future of radio is digital, but that future is not yet. We are unable to make a decision on these results.” A polite way of saying “This is not the digital radio we were hoping for.”
These are just a few brief excerpts of the FM HD Radio test reports from Sao Paulo. The method of testing:
The transmission system was located in the center of the city of São Paulo. The signal HD Radio digital broadcast was extended hybrid mode combined with the analog signal in the air, with separation of 163.8 kHz from the carrier’s analog FM signal and the carriers of HD Radio digital signal in sub-upper and lower sidebands. The power used in transmitter for the analog signal was 27 kW, and for the digital signal of 1 kW. Attaching the FM and HD Radio systems in their respective transmission antennas, the power Isotropic Effectively Irradiated (EIRP) of the analog signal was 112.3 kW and the digital signal of 1.12 kW. Thus, the protection ratio (EIRP power ratio between the analog and digital signals) was 20 dB (sic). During the measurement campaign, two commercial FM receivers were used analysis of analog reception, both to verify their potential impacts on receiving due the introduction of the digital signal, as to assist in verifying the coverage area of the signal analog.
The results of this testing:
Checking the results on each route, the route R1 radial (southeast direction), the stretch P1 to P2, that extends to 10.88 km (7.3 miles) of distance from the transmitter, the audio decoding was 71.6% of the digital audio frames received, and in the remaining sections of the route were little digital coverage.
In radial route R2 (southwest direction) was decoding of digital audio throughout the stretch to P1 P2, which extends up to 10.7 km (6.6 miles) of distance from the transmitter. In the following passage (P2 P3), the first blend was 17 km (10.5 miles) from the station. Following the passage P3 to P4, 26.4 to 44.9 km (27.9 miles), there was only 21.8% decoding of digital audio frames received within that stretch. In the last section (P4 to P5), from 44.9 km, there was almost no coverage digital.
In R4 route (northwest), there was decoding of digital audio throughout the stretch P1 to P2, extending up to 11.8 km (7.3 miles) of distance from the transmitter. In the following passage (P2 P3), from 11.8 to 24.9 km, was 62.5% of decoding digital audio frames received within that stretch. Following the stretch from 24.9 to 47.5 km (29.5 miles), (P3 to P4) the percentage was 24.3%. In the last stretch, from 47.5 to 61.7 km (P4 to P5), no digital coverage.
In route R6 (northeast direction), the stretch up to 9.8 km (6 miles), (P1 to P2) was 74.7% decoding of audio frames. In the passage P2 to P3 from 9.8 km to 29.8 km (18 miles) of the station, there was audio decoding 100% of the received frames. Following the stretch from 29.8 to 45.3 km (28.1 miles) (P3 to P4), the percentage was 87.2%, and in the last stretch, from 45.3 to 60.9 km (P4 to P5), the percentage was 47.9%.
Routes are shown on a map:
Using unbiased real-world testing, HD Radio does not look so hot. One caveat; the digital carrier level is -20dBc. That being duly noted, results show a 112 KW EIRP analog station with a 1.12 KW digital carrier that is unusable 6 miles from the transmitter site in some areas. It is almost hard to believe. Original documents can be found on the Government of Brazil Ministry of Communications website (in Portuguese). They are interesting reading, although you may need to parse them through Google translator.
AM HD Radio (no surprise) and DRM have similar or worse results.
Thus the myth “Digital is better,” is called to question. I am not opposed to new technology, provided it works better than the technology it is replacing.
Hey! Finals are over and I did pretty dern good. I’ll get my GPA sometime next week. Anyway, as a nod to my English 227 (Technical Writing) professor, this appears to the state of things for those that did not take the class:
