LLB8877PMTransmitter for Meter Reading

April 15, 2004 HEXAGRAM, Inc. 23905 Mercantile Rd. Cleveland, OH 44122 216-464-1057 Federal Communications Commission Office of Engineering and Technology Equipment Approval Services RE : Request for Confidentiality Attached Form 731 – Application FCC ID: LLB8877PM Dear Sir or Madam: Hexagram Inc. does not wish to publicly disclose certain technical information which is enclosed with this application. This material contains critical trade secrets and we request that the Commission withhold this information from public inspection pursuant to the provisions of Section 0.457(d) and 0.459 of the Commissions Rules, and Section 552(b)(4) of the Freedom of Information Act. This letter summarizes previously sent to request for confidentiality. MATERIAL TO BE HELD CONFIDENTIAL: File Name Description Pages LLB8877PM Internal photos.pdf Internal Circuit Board Photos Three pages LLB8877PM--Schematic.pdf Circuit Schematics Two Pages LLB8877PM-Operation Desc.pdf Description of Operation Two Pages LLB8877PM-Installation.pdf Installation manual Thirty five pages LLB8877PM-BlockDiagram.pdf Block Diagram of the device One page LLB8877PM-Bill of materials.pdf bill of components and materials Three pages LLB8877PM-Tune Up.pdf Field calibration and tune up One page The LLB8877PM electronic assembly is sealed inside of an electrical meter which cannot be opened without destruction of the seal. The above listed material is confidential and is not available to the public or end user. Sincerely, Lazar Feldman Principal Engineer RF and microwave systems

LLB8877PM EXTERNAL PHOTO

LLB8877PM FCC Label

SMITH ELECTRONICS, INC. ELECTROMAGNETIC COMPATIBILITY LABORATORIES RADIO-FREQUENCY EMISSIONS TEST REPORT FOR HEXAGRAM, INC. ELECTRIC METER TRANSMITTING UNIT (MTU) Model 8877PM FCC ID: LLB8877PM April 5, 2004 Prepared by:__________________________ James R. Pollock Prepared for:Hexagram, Inc. 23905 Mercantile Road Cleveland, OH 44122 Smith Electronics, Inc. 8200 Snowville Road Brecksville, OH 44141 Phone: (440) 526-4386 Fax: (440) 526-9205 FCC ID: LLB8877PM 2 of 18 TEST REPORT INTRODUCTION The Hexagram Electric MTU transmitter is a line-powered transmitter designed to be installed in a typical electric meter. The transmitter will be mounted inside the glass cover of the meter and provide a very short, intermittent radio frequency transmission to provide a remote reading of the meter. A microprocessor provides timing, control and data processing functions. The built in antenna is inaccessible to the user and no provision is made for an external antenna. This report describes the tests performed on the transmitter in support of an application for certification. MEASUREMENTS PERFORMED Power Output and Spurious EmissionsPage 3 Occupied BandwidthPage 9 Frequency Stability vs. TemperaturePage 11 Frequency Stability vs. Supply VoltagePage 12 Transient StabilityPage 14 . The microprocessor portion of the transmitter has previously been examined for conducted and radiated emissions per Part 15, and has been verified to comply with the appropriate sections of that part. The data used for verification of the microprocessor portion is presented in a separate report. FCC ID: LLB8877PM 3 of 18 POWER OUTPUT AND SPURIOUS EMISSIONS A series of measurements of the operating frequencies and any harmonic emissions was made. All measurements below 1 GHz were made on the Smith Electronics open area test site located at 8200 Snowville Road, Brecksville, OH. Data pertinent to this site is on file with the FCC and Industry Canada. Due to inclement weather, the harmonic measurements above 1 GHz were made in an unobstructed area of a garage. The measurements were made using the substitution method described in TIA/EIA-603-A. Measurements below 1000 MHz were made at a three-meter test distance with frequencies above 1000 MHz being measured at one meter. A tuned dipole was used for receiving below 1000 MHz and a wave guide antenna was used above 1000 MHz. A spectrum analyzer was used as the receiver for both distances. The transmitter, installed in a typical meter assembly and housing , was placed on a remotely rotatable, non-conducting test stand. This general set up is shown in Pictorial 1. Because of the intermittent nature of the normally operating transmitter and its mode of operation while AC powered, an external battery pack was connected directly to the transmitter and the transmitter was forced to continually transmit for the measurements. With the test receiver tuned to the unmodulated signal, the transmitter under test was rotated to the position of maximum signal. The receiving antenna was then varied between 1 and 4 meters in height to again maximize the signal. Measurements were made with the antennas positioned both vertically and horizontally and the maximum signal recorded. No differences were observed with different signal detectors, so a peak detector was used for the signals below and above 1000 MHz. Measurements were made with the transmitter tuned to 450 MHz, 460 MHz and 470 MHz. This covers the ends and center of the band to which the transmitter will be tuned in practice. After the maximum received meter readings were obtained for each frequency and polarity, the meter under test was removed from the area and replaced by a signal generator and transmitting antenna. With the transmit antenna placed as close as possible to the position of the test unit, the signal generator was activated at a test frequency. With the signal detected, the receive antenna was positioned vertically for maximum reception. The signal generator output was then adjusted until the received signal was equal to the received signal from the unit under test. These measurements were repeated for each frequency and antenna orientation and the maximum values obtained are noted in Tables 1a – 1c. Transmitting antenna gain and coax loss figures are also included in the Tables. In order to convert the signal generator output value to equivalent radiated power from a dipole, the following equation is used: P d = P g – cable loss(dB) + antenna gain(dB d ) where: P d is the dipole equivalent power, P g is the generator output into the substitution antenna and “antenna gain” is the gain of the substitution antenna with respect to a tuned dipole. According to 90.210(d)(3) all emissions greater than 12.5 kHz from the center of the authorized band shall be attenuated below the unmodulated carrier by 50 + 10log(P). Using P = 0.077 W, the required attenuation is 38.9 dB. An examination of Table 1 shows that all emissions are 43.0 dB or more below the maximum carrier power level. FCC ID: LLB8877PM 4 of 18 PICTORIAL 1 HEXAGRAM 8877PM ELECTRIC METER TRANSMITTING UNIT OUTPUT POWER AND SPURIOUS EMISSIONS TEST SETUP FCC ID: LLB8877PM 5 of 18 TABLE 1a HEXAGRAM 8877PM TRANSMITTER SUBSTITUTION METHOD 450 MHz 3 meter measurement using tuned dipole transmit antenna Frequency (MHz) Gen. Output (dB) V/H Coax Loss (dB) Ant. Gain (dBd) Dipole Eq. Power (dBm) V/H Difference (dB) V/H 45015.2/16.81.1014.1/15.7 34.1/35.7 Required 900-33.8/-35.81.70-35.5/-37.5-49.6/-53.2 1 meter measurement using horn transmit antenna Frequency (MHz) Gen. Output (dBm) V/H Coax Loss (dB) Ant. Gain (dBd) Dipole Eq. Power (dBm) V/H Difference (dB) V/H 1350-44.5/-45.20.83.1-42.2/-42.9-56.3/-58.6 1800-50.3/-51.11.04.9-46.4/-47.3-60.5/-62.9 2250-42.2/-37.41.25.6-37.8/-33.0-51.9/-48.7 2700-39.1/-35.91.36.2-34.2/-31.0-48.3/-46.7 3150-41.4/-36.51.56.7-36.2/-31.3-50.3/-47.0 3600-41.2/-35.71.66.6-36.2/-30.7-50.3/-46.4 4050-39.4/-34.31.76.5-34.6/-29.5-48.7/-45.2 4500-64.4/-59.21.97.2-59.…

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