PHILLIPS MICROTECHNOLOGY's stuff works!
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WMAR-TV uses our equipment within 12' of a PCS Site!

We are in business today, because we have consistently provided technically superior products. We have made a living providing upgrades and retrofits for problems in other manufacturers' equipment. Filtering is bulky, tricky, time consuming to tune correctly, and expensive. Each system we sell is matched to its own LNA that is custom made for that particular station. While some companies are showing you the insurmountable problems encountered with PCS, we have provided Ultra-Selective, Ultra-Sensitive equipment for the past four years.

WMAR-TV's ENG receive antenna is 12 feet away from a PCS site, and at the same elevation--no vertical separation!  With the help of our SuperFilter, they cleanly receive ENG signals over the complete 2 GHz Band, including channel 1.   Other companies lead you to believe that anything under 2 miles, can't be done, and suggest that you "live with it." 

Our premier product, our special signal conditioning, SuperFilter/LNA, stands far above anything available from anyone else at any price. It can be added to virtually any antenna system. It is unbeatable for delivering a high quality signal, under all conditions, and can be used with Heliax runs up to 2000 feet, using 7/8" line. That is why KMTV-TV ordered a new RF Technologies antenna system, but specified a PHILLIPS MICROTEK SuperFilter/LNA. This is why the COSMOS Group Stations had MICROWAVE RADIO ship us their brand new Ultrascan antennas, to be upgraded with our SuperFilter/LNA, prior to installation.

above: Unmodified Ultrascan for WAVE-TV, Louisville, KY.

below: Modified Ultrascan for WLOX-TV, Biloxi, MS.

WLOX-TV Upgraded their new Ultrascan antenna with our SuperFilter/LNA prior to installation.

Today the spectrum is becoming even more crowded, with some services (PCS) requiring very high power levels, because of poor spectrum planning. Many ENG receive sites share their space with high power transmitting equipment. This is why we have consistently used more expensive components in our LNAs. We are noted for providing extremely sensitive LNAs. Our amps have high headroom, with intercept levels (IP3) typically 10 db greater than anyone else, to allow clean amplification without distortion or intermodulation (mixing signals).

You can see (or have already seen) this problem with LNA Intermodulation, but filtering the signal before it hits the receiver, is even more important.

The input filter removes out of band signals, and prevents these signals from being amplified. If you have a 0 dBm interfering signal, and a 30 db gain LNA, if the filter only reduces the signal -30 db, the 30 db gain LNA will bring the signal right back up to 0 dBm! This is the reason we are so careful with our filtering. Here is a picture of what the MICROWAVE RADIO filter looks like:

A Wiltron 6647A Sweep Generator, with a leveled 0 dBm output, was connected to the input of the MICROWAVE RADIO bandpass filter. The sweep was adjusted to start at 1700 Mhz, and end at 2700 Mhz. The output of the filter was connected to our Tektronix 2782 spectrum analyzer. High quality Gore cable was used for all connections. The response is displayed in the picture above. You can see that the filter has virtually no rejection from about 1930 Mhz. to 1990 Mhz. The MICROWAVE RADIO filter passes the whole PCS Spectrum!

The red trace, below, is the same MICROWAVE RADIO filter. The green trace is what the signal looks like through the PHILLIPS MICROTEK SuperFilter/LNA, shipped to WLOX-TV.

Notice the sharp rejection at the edge of the 2 Ghz band. This is the area of the green trace that comes from the left side, and then sharply rises to pass the frequencies in the 2 Ghz band from 1992 to 2108 Mhz. After 2108 Mhz, the response falls rapidly to reject MDS. The next response, shown to the right, is the 2.5 Ghz band, from 2450 to 2485 Mhz. The response drops off rapidly, to reject Wireless Cable, ITFS, and MDS. No PCS signals can make it through our temperature compensated filters alive. Wouldn't you want this type of response when more of those PCS towers start going up on "C" Block (1975-1990 Mhz)?

The photo below is an enhancement of the lower side of the 2 Ghz band. The image is a negative, to bring out the traces even more. The sweep starts at 1800 Mhz, and ends at 2 Ghz. The green trace is the MICROWAVE RADIO filter response. The red trace is the PHILLIPS MICROTEK SuperFilter/LNA. As you can see, the PCS Band (and everything else) is virtually gone!

REJECTION: (elimination of unwanted signals in LNA system before signal hits receiver)

All measurements were referenced to 2050 Mhz. Only the PHILLIPS MICROTEK SuperFilter/LNA-SP3, is designed to work with PCS sites nearby.  PCS transmitters will degrade or overload virtually all other systems.

In conference calls in our dealings with the COSMOS Stations, it was necessary to divulge to MICROWAVE RADIO and to RADIO WAVES, the company who makes the electronics for MICROWAVE RADIO, some of what we were doing to modify their equipment, and the reason behind it. We assume that MICROWAVE RADIO and RADIO WAVES have adopted tighter filtering, and improved headroom. We however, have also improved!

The following is a typical call, the kind that keeps us in business:

In early April, we received a call from Richard Danysh, at KABB-TV, San Antonio, Texas. He was having interference problems with his 3 year old MICROWAVE RADIO ULTRASCAN Antenna System and MILLENNIUM Receiver. After talking with him and having him describe the problem and his location, we determined it was the third harmonic of UHF TV channel 41, located about a mile away, that was causing his system to overload. The third harmonic of channel 41's 633.25 Mhz visual carrier is 1899.75 Mhz. The aural carrier for channel 41 is 637.75 Mhz. The third harmonic is 1913.25 Mhz.

At 1900 Mhz, the MICROWAVE RADIO ULTRASCAN LNA System attennuates signals only 7 db, while the PHILLIPS MICROTEK SuperFilter/LNA is greater than 80 db down in the picture, and when measured with a sensitive Network Analyzer, filter attenuation is greater than 140 db down. As you can see from the information above, if they had purchased our SuperFilter/LNA, they would not have this problem! We have provided a quote to KABB-TV to retrofit their system with our high selectivity, low loss filters. The unwanted signal was also getting through the unshielded wiring harness, which was acting like an antenna.

*On April 17, 1997, right after Bob Morgan, WCTV-TV in Tallahassee Florida, ordered 2 more PCS filters, Richard Danysh, KABB-TV, again called. He told us that he had to replace boards in his Ultrascan Antenna this week. They had become defective due to rain from a crack in the radome. He did notice 2 silver filters mounted in his Ultrascan Antenna. He had only ~7 db of rejection from this 5 Megawatt UHF station! He ordered our upgrade kit.

** On July 30, 1997, Richard Danysh of KABB-TV, San Antonio, finished installing our upgrade kit, and sent the following message to my pager: "WORKS GREAT!" On a follow-up conversation, he reported receiving their ENG van perfectly, 35 miles away, on low power. He was a happy camper!   If you don't believe us, give Richard a call at KABB-TV, (210) 366-1129.

Please remember: Every unwanted signal that reaches the mixer in your receiver, subtracts from your range, and adds noise to your video and audio.

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