ERG l NEERi iiG REPORT 

------------------ 

MAr,UETI C F l EL2 STREtGTd MAPP l iG OF 

ME HELVETIA COAL CO. LUCERNE #5 

MliJE AT MEDl iJM FREQUEiJCY 

-Contour naps of nasletic field stren~th 

along North and South Main haulagekays 

are presented at frequencies of 71,225, 

910, and 2690 KHzPREPARED FOR: U.S. Bureau of ;*lines 

PI fS RC 

Cochran ?~ll I I Road 

Bruceton, Pennsylvania 

Under: U.S. Bureau of Mines PO372716 

PREPARED EY: Terry S. Cory, P.E. 

2515 Linden Dr. S.E. 

Cedar Rapids, Iowa 52403 

- September 1977 - 
PREPARED FOR: 

PREPARED EY: 

EM2 I NEERl 1.iG REPORT 

------------------ 

MAGNETIC FIELD STRENGTH MAPPING OF 

ME HELVETIA COAL. CO. LUCERNE #8 

MINE AT MEDIUM FREQUENCY 

-Contour maps of magnetic field strength 

along North and South Main haulageways 

are presented at frequencies of 71,225, 

910, and 2890 KHzU.S. Bureau of ;.lines 

PIiSRC 

Cochran Mi I I Road 

Bruceton, Pennsylvania 

Under: U.S. Bureau of Mines PO372716 

Terry S. Cory, P.E. 

2315 Linden Dr. S.E. 

Cedar Rapids, Iowa 52403 

- September 1977 - 
TABLE OF CONTENTS 

PAGE 

1.0 Introduction 

I. I General Background 

1.2 Description of the Test Environment 

2.0 Summary of Results 

3.0 Experi menta I Approach 

4.0 Data Reduction Techniques 

APPENDIX - Raw and Reduced Data from the Lucerne 

#8 Mine Testing 
TABLE OF ILLUSTRATIONS 

F l GURE PAGE 

/-I Map of Lucerne #8 Mine Showing Transmitter 1-3 

Location and Field Strnegth Test Locations 

In North and South Mains 

Main Haulage Entry Crossections Geometry 3-2 

for Measurerents 

Transmitter Equipment Used for 71 KHz 3-5 

Transmitter Equipment Used for 225,910, 3-6 

and 2890 KHz 

Magnetic Field Strength Coverage Map of 3-7 

Lucerne #8 Mine With the Transmitter PI aced 

Adjacent to the Power Cable at the Junction 

of the North 8 South Mains Belt Entries - 71 KHz 

Magnetic Field Strength Coverage Map of 3-8 

Lucerne #8 Mine With the Transmitter Placed 

Adjacent to the Power Cable at the junction 

of the North 8 South Mains Belt Entries - 225 KHz 

Magnetic Field Strength Coverage Map of 3-9 

Lucerne #8 Mine With the Transmitter Placed 

Adjacent to the Power Cable at the Junction 

of the North 8 South Mains Belt Entries - 910 KHz 

Magnetic Field Strength Coverage Map of 3-10 

Lucerne #8 Mine With the Transmitter Placed 

Adjacent to the Power Cable at the junction 

of the North 8 South Mains Belt Entries - 2890 KHz 
1.0 INTRODUCTION 

1.1 GENERAL BACKGROUND 

This report describes magnetic field measurements in the Heivetia Coal Cc. 

Lucene #8 Mine for purposes of deriving a mapping of the magnetic field 

strength covering the major haulageways which contain conductors. 

The measurements were performed by Terry S. Cory, P.E. under U.S. Bureau 

of Mines purchase order P0372716. Assisting in performance of the 

measurements were personnel from the Bureau of Mines, PMSRC, and Helvetia 

Coal Co. 

Acknowledgement is given to Engineer Tom Strong of Helvetia Coal Co. who 

accompanied the neasurement team and who lended support in performing the 

measurements and in supplying valuable engineering information for use In 

evaluation of the results. 

The results of the testing at medium frequency show that coverage of the 

entire mine area containing conductors can be achieved employing wireless 

radio techniques whereby radio signals are coup led into and are carrled 

by these conductors. These results confin earlier qualitative testing of 

the Collins Mine Wireless Radios in this mine. These results, performed 

over the frequency range 71 -2890 KHz, i l l ustrate the effect of frequency 

on the radio propagation with the conclusion that the best overall coverage 

is obtained at frequencies approximati ng 1000 KHz. 

This report presents all the raw data and the reduced data in the form of 

magnetic field strength contour maps. Sufficient information is provided 

to enable independent reduction of the data. A summary of observations 

which can be made directly from the contour maps is given. 
1.2 DESCRIPTION OF THE TEST ENVIRONMENT 

The Lucerne #8 Mine is in low coal in the upper Freeport ( E ) seam 

in Indiana County, Pennsylvania. Haulage entries in this nominally 

42-inch seam have been trenched out to a height of about 6 feet, thus 

accomdating vehicles designed for high coal. This newly developing 

mine is currently less than a mile square. The mine is AC only, 

employing belt haulage and battery operated tracked service vehicles. 

The measurements were perfoned over the existing extent of the :lorth 

and South Main haulageways with supplementary data gathered in the 

adjacent entries and in butt sections off the North kiains. Tne 

measurements were perfoned by two teams working away from a single 

transmitter and employed specific measurement locations as shown on 

the mine map of Figure I-I. Details of the haulageway entry crossectional 

geometries are given in Section 3 to follow. These entries contained 

the belt, 7200 VAC power cable, phone line, and track at a minimum. 

The Mains consist of a 7 or 8 entry pattern with pillars on 60-70 

foot centers. The 3 or 4 central entries are fresh air and the two 

outside entries on each side of the pattern are return. air. 
FIGURE 1-1 

MAP OF LUCERNE #8 MINE SHOWING TRANSMITTER LOCATION 

AND F l ELD STRENGTH TEST LOCAT I OIdS I N NORTH 8 SOUTH MA l 

2.0 SUMMARY OF RESULTS 

Generally, the results of the field strength mapping at 7i1225,910, and 

2890 KHz show that field strength levels in entries containing conductors 

are high enough to support "w i re less" comnuni cations throughout the 

existing mine. This is a qualitative judgement based on the fact that it 

was possible to measure signal levels using the field strength meters 

in all except a few of the measurement locations at 71 KHz. As expected, 

the field strength levels increased with increase in frequency due to 

the improved coupling into the mine wiring. This does not mean that the 

ultimate maximum communication range for transmitters and receivers both 

closely coupled to the conductors increases in a similar manner as the 

attenuation, once coupling into a conductor has been achieved, is quite 

low at low frequencies ( barring variation In field strength levels due 

to standing waves along conductors). 

Estimates of the field strength in the supposedly conductor-free "angular 

sector" region between the North and South Mains show increasing 

coverage with increase in frequency over the test frequencies used. These 

estimates were provided by the contours drawn joining areas in the 

respective North and South Plains. Correspondingly, the fields were clearly 

closely bound to the conductors at 7 1 KHz. 

From the junction point where the transmitter was located, the dorth and 

South Piains were rather symnetrical iy excited at the lower frequencies. At 

the higher frequencies, the South Main conductors were excited more 

strongly by a factor of from 10 to 20 dB. 

At higher frequencies, the fields coupled parasitically to conductors in 

adjacent entries. This was clearly demonstrated in the South Main in the 

reoion of Tas Location 335 where coupling at 71 Wz to conductors in the 

adjacent right-hand entry was barely noticabie , but coupling at 910 Khz 

was such that near-equal field strengths were oroduced by the excited and 

parasitic conductors. 
The effect of standing waves along conductors was much more apparent at 

the higher frequencies than at the lower frequencies. Max-to-min fie Id 

strength readings between high and low signal standing wave points were 

typically 20-25 dB. The resolution of the measurement point locations 

was not sufficient to positively identify the maximum and minimum 

standi n~ wave points although the reduced fie Id strength contour maps 

provide the best estimates of these points which can be obtained from 

the test data. 

Except for a few points at 71 KHz, the measured field strengtn vias 

greatest near the AC power cab le and decreased r:,onotonical l y across the 

entry crossection. The field strength near the belt cabling was typically 

4-12 dB less than that masured at a similar distance away from the AC 

power cable. The belt and power cable were always on the left side of 

the $try when facing away frm the transmitter. The left rib-to-right rib 

decrease in field strength in the main haulage entries was typically 

25-35 dS. 

Considering overall coverage of the haulage entry, both over the entry 

crossection and along the entry, the best frequency of those measured was 

910 KHz. Although the mapping at 2890 KHz was restricted in exten-r, the 

mapping indicated a more rapid fall-off of field strength with distance 

away from the transmitter than was experienced at 910 YSlz. The 71 KHz field 

strength, although adequate along the main haulageways, did not extend 

into the 4-Butt section in the PJoth Main at measurable levels. 
3.0 EXPEHI MENTAL APPROACH 

The transmittercs) was set up at the beltway junction of the North and 

South Mains. Measurements were performed by two teams; one team following 

a traverse along the North Main and the other team following a traverse along 

the South Main. Measurements along each traverse were repeated with 

each change in transmit frequency. Four transmit frequencies were used; 

71,225,910, and 2890 KHz. Each traverse was taken generally along the 

belt entry ( which also contained the track, AC power cable, phone line, 

and periodically the water line with occasional excursions, when 

practical, into the adjacent right-hand entry. In addition, the North Main 

traverse included excursions into the belt entries of the 2-Butt and 

4-Butt sections. 

The locations along each traverse at which measurements were made are 

shown on the mine map introduced in Section I as Figure 1-1. 

Measurement locations were established roughly every 6 crosscuts along 

the belt entries. Typical entry crossectional physical geometrles for 

measurement locations in the North and South Mains are given in Figure 3-1. 

At locations along the North Main traverse, measurements were generally 

made from left-to-right across the belt entry referenced to facing away 

from the transmitter. Veasurements at most locations ( proceeding frm 

left-to-right ) included: 

(1) AC power cable to the left of the belt, suspended from 

the roof and just away from the left rib 

(2) along the belt cabling adjacent to and to the rlght of 

the be1 t 

(3) at the track center 

(4) in the crosscut along the belt entry right rio plane 

(5) in the crosscut, near the right-hand barrier ( stopping) 

At locations along the South Main traverse, measurements were generally 

made from left-to-right ( also as observed facing away from the transmitter). 
LEFT RIB 

PLANE \ / 7200 "IC 

RIGHT RIB RIGKT 

PLANE BARR l ER 

I7 FEET -1

PIORM MAINS MEASURII'IG POIIiTS (A)l(8)n(C)l(D)n(E) 

SOUTH MA l liS blEASUKI NG PO l iJTS (6) (0) (E) 

FIGURE 3-1 

:'!A l i.( HAULAGE E:ITRY CHOSSECT I tit.IS FEOi.lETkY FOk i:EASGREIIENTS 
Measurements at most locations included: 

(1) along the belt cabling adjacent to and to the right of 

the belt 

(2) in the crosscut along the belt entry right rib plane 

(3) in the crosscut, near the right-hand barrier. 

Mcst measurements were performed with the receive antenna orlentation In 

the HMD position with the loop antenna plane being parallel to the entry 

direction (or to the belt or power cable, etc. . Typical proximity of 

the receiving loops to the belt and power cables are illustrated in Figure El. 

The multi-turn transmit antennas were each, in turn, tightly coupled to 

the AC power cable located in the South Main portion of the beltway junction. 

The transmit antennas were oriented HMD. At 71 KHz, the transmitter 

consisted of a Pyott Boone portable trolley phone ( with self-contained 

battery and a special 10-turn antenna. The transmit NIA was 7.43. This 

71 KHz set-up is il lustrated in Figure 3-2. At each of the higher frequencies, 

the transmit equipment set-up was the same as that developed for use during 

the Propagation of El4 Signals in Underground E~lines, contract H0366028. This 

latter test set-up is i l lustrated in Figure 3-3. 

The raw data and the reduced data have been compi led and are given in the 

Appendix to this report, with annotations. The majority of the reduced data 

has been used in the preparation of magnetic field strength coverage maps 

at each of the four frequencies. 

The magnetic field strength coverage maps are given as Figures 3-4 through 

3-7. 

It should be mentioned that these maps portray the magnetic field strength, 

propagated largely via mine wiring, frm this transmit location, to the 

extent made possible within the limitations of the measurement points. 
Coverage not shown, for example, along several of the North Main butt 

sections means that measurements were not made in these sections. Also, 

while the field strength in entries parallel to the measured main 

haulage entries can be expected to fall off monotonically with Increasing 

distance perpendicular to the haulage entries when no conductors are 

present, the presence of conductors in these entries will enhance the 

coverage. 

The transmitter location, while perhaps advantageously located, produces 

results that may be typical for a base station located elsewhere in the 

region near the main portal if equally tightly coupled to the power cable. 
7200 VAC POWER CABLE 

I 

3-6 I t4CHES 

I 

10 TUR'dS #I2 WIRE 

DIAi4 (EQUIV ) = 3 FEET 

PYOTT BOONE 25 OHbl 

TROLLEY PHONE 

0'707(40) = 1-13 Hi.IP iiMS CURRENT = 25 

NIH = 7.43 

7.91, 

FI GU2E 3-2 

TRANSM l TTER EQU I PKENT USED FOR 7 1 WZ 
FIGURE 3-3 

TRAElSlOlTTER EQUIPI,IEI.IT USED FOR 225, 910, AidD 2690 KHZ 

7200 VAC POWER CABLE 

5 

2-FOOT Dl AM 

4-TUR4 1000 KHz 8 ABOVE 

. 

7-TURN BELOW 1000 KHz 

4-TURN NIA = 1.17 FOR 

I AMP 

7-TURN NIA = 2.04 FOR 

S IGi4AL 

GENERATOR 

HP-65 18 

4 

L-SECT I ON I AMP 

MATCHING 

Ut.I I T 

150 WATT 

INVERTER 

- 

I 

25 VDC 

GATES 

-- 

BATTERY 

PACK 

12 VDC 

GATES 

BATTE2Y 

PACK . 

POWER 

AMPLI FI ER 

EN I -300P 
10 DB CONTOUR INTERVAL SCALE : I INCH = 

, ,111 

11'1 I SOUTH MAINS 

T 1 7 T i -1 - I- \---- ---__ 

I I I I I I. I 1-7 I I;TTI r I I 1 I I 1-1 I. -,__ I I I .I 

----- - - - -1 ---- 

-I T .T 17Tt T I I I ,I I I~ ..~i 1-1 1.1 

1- I 7 ' /~ 1 1, 

----I- --- I I . -. .- - - - - - - I- - .-, - /(.I ,-t,,t; ; ; j 

- .- - +G 1 I! 'J .~ ----- I 6 I I- '-;--L-i-'-,- - -- 1 

'- 

I I I I I ; I 1 I- fi h I 1 I 1 I I I 1 11 I ,.I ______- --- -- - - 

1 T-IT,--~~I-~~ 1 \ 1 

1-.L 

111 1 -i 11 1 - 1 I' t (1-1-L- - - - - --- I 0, 

-- I I I- - --rr~Ll-r- - I - I - -I+ I - - - 1- - _- - I , - I - , - I -- j -{ 

FIGURE 3-4 

MAGNETIC FIELD STRENGTH COVERAGE MAP OF LUCERNE $8 MINE WITH THE TRANSMITTER PLACE0 

ADJACENT TO THE POWER CABLE AT THE JUNCTION OF THE NORTH AND SOUTH MAINS BELT ENTRIE 

71 KHz 

MAGNETIC FIELD STRENGTH GIVEN IN DB GREATER THAN I MICROAMP PER METER, TRANSMIT NIA 
300 FEET 
FIGURE 3-5 

WGNETIC FIELD STRENGTH COVERAGE MAP OF LUCERNE #8 MINE WITH THE TRANSMI 

ADJACENT TO THE POWER CABLE AT THE JUNCTION OF THE NORTH AND SOUTH MAINS 

225 KHZ 

MAGNETIC FIELD STRENGTH GIVEN IN DB GREATER THAN I MICROAMP PER METER, 1 

10 DB CONTOUR I NTERV, 

SOUTH MA1 NS 

- ----- 

---- r I I I I I I I I I /I I IT/ T~7jT71Ti-77

L__- 

I I I I I I I 1 TITIT 1-17 7-17 TI TIT II\I 7 

I I r I I I ~r-rr~~~r~-j-rlr T/-r~Tl~/

-----L_ ------ 

I \ d 

FIGURE 3-6 

MAGIdETIC FIELD STRENGTH COVERAGE MAP OF LUCEF?'.IE #8 MINE WITH THE TRANSMIT1 

ADJACENT TO THE POWER CABLE AT THE JUCTION OF THE NORTH AND SOUTH MAINS BE 

910 KHz 

MAGNETIC FIELD STRENGTH GIVEN IN DB GREATER THAN I MICROAMP PER METER,TRAF1 

/ 

V) I1 

W 

0 - a 

wx - 

O c Z 

a 2 

J W 

a 

t- - 

I- 5. 

x J 

W w %? 

c n a 

c - LT 

V) Iz Z 

V) - . x $2 w 

c z 

c 

Li 

r 

w= x z5: u 

CL 

F 9 - a 

a 

x 

I 

2 

We 

z n 

2 

- O 

0 - 

-z 2 z 

103 ul - m* 

w 3 

Z LL N I 

WWO~C 

x W 

302 a: 

C3330W - A-0-tLL cwa 

LLONW 

1 Oi5 a 

LL 7 

a 30 

z w n 
4.0 DATA REDUCTION TECHNIQUES 

The NM-12 and NM-25 field strength meters have been calibrated so that 

a known incident field strength will produce readings of +25 dB and +I0 dB 

respectively on the instrument panel meters with the attenuator in the 

-20 dB position. This known incident field strength is in terms of 

microvolts/meter ( the plane wave equivalent electric field . As the 

calibration was actually performed using loop antennas, the true H 

calibration field strength is given by dividing the equivalent electric 

field strength by 377 ohms. 

The calibration equivalent electric field strengths used to reduce the 

data presented in this report were: 

RX AFITEi4PIA FREQUENCY Fl ELD STREXGTH 

SAND SET # KHz MICROVOLTS/I' 

3 low freq tuner 7 1 103 

I high " It 225 7 1 

2 " " I, 9 10 34.9 

4 !, It 1, 2890 13.5 

In reducing the field strength data the field strength at each location in 

dB greater than I rnicroarnp/seter was found as the sun of the readin? as 

determined in dB minus the field strength meter calibration point In dB 

plus the attenuation range setting plus 20 dB Plus the calibration field 

strength in da greater than i microam;/-~eter plus :he :IlA norrizl izzticn 

factor. In equation form, this is expressed as 

10 for '1:'-25 + attenuator Field Strength = analog meter reading - 25 for N:d-12 

range setting + 20 + calibration field stren~th 

2.5 

+ 20 Logig ( ix current x Tx ant 1 

,. Tx ant NiA = 7.43 for ?yott Eoone systen 

2.04 for 7-turn loop below 1300 KHz 

1.17 for 4-turn looo above 1003 Khz 
The reduced field strength values corresponding to each frequency were 

plotted on an overlay paper on a I inch = 200 feet scale mine map having 

the measurement points previously located. Field strength contours were 

plotted based on the distribution of data points and previous experience. 

The map overlays were reduced to a scale of I inch = 300 feet for presentation 

in this report using Xerographic techniques. 
- APPENDIX - 

RAW AND REDUCED DATA FROM THE LUCERNE #8 MINE TESTING 

THE RAW DATA CONS1 STS OF MAGNETIC FIELD STRENGTH TAKEN WlTH THE NT.1-12 OR 

NEI- 25 FIELD STRENGTH METERS UNCORRECTED FOR THE INSTRUMENT CALIBRATION 

AND NIA NORMALIZATION FACTORS. CORRESPONDING TO EACH READING, THE RUDUCED 

MAGNETIC FIELD STRENGTH IN DB GREATER THAN I MICROAMP PER METER IS GIVEN 

EMPLOYING THE DATA REDUCTION TECHNIQUE DESCRIBED IN SECTION 4 OF THE REPORT. 

TEST #I 71 KHz WlTH 1.13 AMP INTO TX ANTENNA (NIA = 7.43 ) RX ANTENNA BAND 3 

USING LOW FREQUENCY TUNER, REDUCED DATA NOFMALIZED TO NI A = 2.5 

SOUTH MA l NS 

TAG LOCATION 

53 

? 

NORTH MAINS 

STAT l ON 

I 

ADJACENT TO BELT 

RAW DATA REDUCED DATA 

+I l +20 +5.3 

+ 8 +20 +2.3 

+ 7 +20 +I .3 

+I2 +20 +6.3 

+6 0 -19;7 

+23 -20 -22.7 

+I0 0 -15.7 

+7 0 -18.7 

+27 -20 -18.7 

RAW DATA REDUCED DATA 

+23 +20 +17.3 

+I 3 +20 + 7.3 

+I9 0 - 6.7 

RIGHT RIB 

RAW DATA REDUCED DATA 

+20 -20 -25.7 NEXT ENTRY OVER 

EI4T2Y CENTER 

LOU847 

- NOTES 

TRACK CENTER 

ADJACENT TO EiELT ( I FOOT AWAY) 

TRACK CENTER 

+I I+ -20 -34.2 AGA IEIST RIGHT BARR I EX 

+I2 +20 + 6.3 UN l FOP$! OVEI? AREA, J UFICT I ON OF I -EUTT 

NEAR BELT 

+24 0 - 1.7 UN I FORY OVEii JU'JCTI 014 

124 0 - 1.7 I FOOT FROil 3ELT 

+I5 0 -10.7 TRACK CEITER 
NORTH F4AINS( CONT.) 

- STAT l ON RAN DATA 

6 +20 0 

+I3 0 

+I2 -20 

+I8 -40 

+I2 -40 

+23 0 

+I3 0 

+I 8 -20 

+24 -40 

+I6 -40 

REDUCED DATA 

- 5.7 

-12.7 

-33.7 

-47.7 

-44.2 

- 2.7 

-12.7 

-27.7 

-41.7 

-49.7 

-49.7 

- NOTES 

I FOOT FROE.1 BELT 

TRACK CENTER 

RIGHT RIB PLANE 

2IGHT BARRI ER ( 25 FEET AVYAY 

[:31SE 9 CIICHT BAR2IE3 

I FOOT FROM BELT 

TRACK CENTER 

RIGHT RIB PLANE 

RlGH T BARRl ER ( 15 FEET AWAY ) 

NEXT E;JTRY R I GET, LEFT 'I a PLP,YE 

ilEXT EIJTiiY RlGiiT,2lS~iT 215 FLAiiE 

V!,!D; il::: 51^:iAL I:I ii3ISE 

;IEXT EiiTRY OVE?, ZI,SdT SA23IEE 

( 25 FEET NIAY 1, Vl49, $ 9E AaOVE 

I40 I SE 

NOl SE UN I OVE5 JU>lCT ION, N3 

S IGIIAL, JUNCTl3i.I OF i3ELT DRl VE AN0 

END OF TRACK 

P.IOISE 40 FEET AWAY FROI,,l END OF TRACK 

TRACK CENTER 

pi01 SE e TRACK CEI~TER, 140 s I GNAL 

PIOISE OVER BELT, EQUIDISTAYT SETWEEN 

POWER CABLE AilD PHOIJE LlNE 

tiOISE, NO SIGlikL, LEFT OF BELT ALONG 

LEFT Rld "FLAT" SlCE OF CABLE.6 ll4Cti 

FROM POWER CABLE 

LEFT OF CELT ALOliG LEFT RIB $CABLE 

LEFT OF BELT ALONG LEFT RIB SCABLE 

LEFT OF BELT ALONG LEFT Rla 8CABLE 

LEFT OF BELT ALOiiG LEFT RIB GCAJLE 

6 INCHES FROM PiATER LlNE 8 PHONE LlNE 

RUiJNI NG ALONG RIGHT OF aELT TOWAR9 

ENTRY CENTER 

TRACK CENTE2 

RIGHT RIB PLANE, tiI'D 

RIGHT RlE PLANE, H;'iD/V;4D (45 DEG TILT 

R l GHT BARR l ER 
NORTH MAINS( CONT.) 

STAT l ON RAW DATA 

I I +29 -40 

+I5 -40 

+22 -20 

+25 -20 

REDUCED DATA 

-36.7 

-41.2 

-23.7 

-20.7 

- NOTES 

TRACK CENTER 

NOISE 8 TRACK CENTER 

LEFT @ BARRIER 

AT POWER CABLE CROSSING AT RIGHT 

ANGLE TO POWER CENTER 

LEFT OF BELT ALONG LEFT RIB @CABLE 

VE.!D, ENTRY ENTER 

HI.ID, ENTRY CENTER 

ENTRY CENTER 

LEFT OF BELT ALONG LEFT RIB @CABLE 

TEST #2 225 KHz WITH 0.76 AMP INTO TX ANTENNA ( NIA = 1.55 RX ANTENNA BAND I 

USING HIM FREQUENCY TUNER, REDUCED DATA NOFP4ALIZED TO NIA = 2.5, 

NM-12's USED FOR THIS TEST 

SOUTH MAINS 

TAG ADJACENT TO BELT RIGHT RIB Rl GHT BARRl ER 

LOCATION RAW DATA REDUCED DATA RAN DATA REDUCED DATA RAW DATA REDUCED DATA 

5 1 +27 +20 +31.6 +I8 +20 +22.6 

6 8 +I8 +20 +22.6 +9 +20 +I36 

+20 +20 +24.6 + 6 +20 +10.6 +25 -20 -10.4 

+35 +20 +39.6 +30 +20 +34.6 

+25 +20 +29.6 +I5 +2D +19.6 +I9 +20 +23.6 

+I4 +20 +18.6 +I5 0 - 0.4 

+25 +20 +29.6 +I5 +20 +19.6 +I5 +20 +19.6 

EXTRA DATA POINT, CENTER OF NEXT RIGHT ENTRY. LOTS OF CONDUCTOR 

AND TRACKS +25 +20 +29.6 

+I7 +20 +21.6 +I9 0 + 3.6 +7 0 - 8.4 

+35 0 +19.6 +I3 0 - 2.4 +6 0 - 9.4 

+25 +20 +29.6 +21 0 + 5.6 +7 0 - 8.4 

+20 +20 C24.6 +20 0 + 4.6 +23 -20 -12.4 

LOOSE RAI LS TOSSED 

AEOUT 
NORTH MA INS 

STAT 1 ON 

2 

RAW DATA 

+I4 +60 

+30 +20 

+ 8 +40 

+I6 +20 

+ 7 +20 

+20 +20 

+I84 0 

+ 3 +40 

+I4 +40 

+ l +40 

REDUCED DATA 

+58.6 

+34.6 

+32.6 

+20.6 

+I 1.6 

+24.6 

+ 3.1 

+27.6 

t38.6 

+25.6 

+13.6 

- 1.4 

+33.6 

+25.6 

+26.6 

+30.6 

- NOTES 

LEFT OF BELT @ POWER CABLE 

HELD TO BUTT, BELT 

I INCH LEFT OF BELT 

TRACK CENTER 

RlGHT RIB 

ENTRY CENTER 

ENTRY CENTER, VMD 

LEFT OF BELT @ POWER CABLE 

ADJACENT TO 8 RIGHT OF BELT 

TRACK CENTER 

RIGHT RIB PLANE 

RIGHT BARR I ER 

LEFT OF BELT @ POWER CABLE 

ADJACENT TO 8 RIGHT OF BELT 

TRACK CENTER 

RIGHT RIB PLANE. PERPENDICULAR TO 

CABLE 8 POWER CENTER 

PARALLEL TO 8 6 INCHES AWAY FROM 

CABLE 

LEFT OF BELT @ POWER CABLE 

ADJACENT TO 8 RlGHT OF BELT 

TRACK CENTER 

RlGHT RIB PLANE 

RlGHT BARRIER ( 10 FEET AWAY ) 

LEFT OF BELT @ POWER CABLE 

ADJACENT TO 8 RIGliT OF BELT 

TRACK CENTER 

RlGHT RIB PLANE 

RlGHT BARRl ER ( 25 FEET AWAY ) 

LEFT OF BELT @ POWER CABLE 

ADJACENT TO 8 RlGHT OF BELT 

TRACK CENTER 

RlGHT RIB PLANE 
NORTH MAINS ( CONT. ) 

- STAT l ON RAW DATA 

8 + 4 +20 

+ 3 +20 

+I2 0 

+3 0 

+ 4 -20 

+I7 0 

+23 0 

+I3 0 

+I4 -20 

REDUCED DATA 

+ 8.6 

+ 7.6 

- 3.4 

-12.4 

-31.4 

+ 1.6 

+ 7.6 

- 2.4 

-21.4 

-27.4 

+28.6 

+0.6 

+17.6 

+ 1.6 

- 5.4 

- NOTES 

LEFT OF BELT @ POWER CABLE 

ADJACENT TO 8 RIGHT OF BELT 

TRACK CENTER (BETWEEN TWO JEEPD ) 

POWER STAT I ON TRANS FOFJL'IER 

I ENTRY PAST 8 AND END OF TRACK 

LEFT OF BELT @ 4OWER CABLE 

ADJACENT TO 8 RIGHT OF BELT 

TRACK CENTER 

LEFT RIB PLANE 

R l GHT BARR l ER 

LEFT OF BELT @ POWER CABLE 

ADJACENT TO 8 RIGHT OF BELT 

TRACK CENTER 

LEFT R16 PLANE 

RIGHT BARRIER 

TEST #3 910 KHz WITH 1.0 AMP INTO TX ANTENNA ( NIA = 1.17 1 W ANTENNA BAND 2 

USING HIGH FREQUENCY TUNER, REDUCED DATA NORMALIZED TO NIA = 2.5 

SOUTH b1AI NS 

TAG ADJACENT TO BELT RIGHT RIB RI CHT EARRI ER 

LOCATION RAW DATA REDUCED DATA RAW DATA REDUCED DATA RA\I DATA REDUCED DATA 

5 1 +I6 +40 +51.9 +25 +20 +40.9 

6 8 +I5 +40 +50.9 +I9 +20 +34.9 

76 +12 +40 +47.9 +I5 +20 +30.9 + 9 +20 +24.9 

l I0 +20 +40 +55.9 +24 +20 +39.9 

277 +27 +20 +42.9 +I0 +20 +25.9 

335 +I3 +40 +48.9 +22 0 +17.9 +35 0 +30.9 

EXTRA DATA POINT, CENTER OF NEXT RIGHT ENTRY 

+27 +20 +42.9 

387 +30 +20 +45.9 +25 0 +20.9 

446 +25 +20 +40.9 +I0 +20 +25.9 

476 +23 +20 +38.9 +22 +20 +37.9 

507 +20 +20 +35.9 +7 +20 +22.9 
NORTH MAINS 

STAT I ON RAW DATA REDUCED DATA - NOTES 

2 +25 +40 +60.9 LEFT OF BELT @ POWER CABLE 

+I3 +40 +48.9 ADJACENT TO 6 RIGHT OF 3ELT 

+I7 +20 +32.9 TRACK CENTER 

+I7 0 +12.9 RIGHT RIB PLANE 

13 + 54 +20 +21.4 ENTRY CENTER 

+ 34 0 - 0.6 ENTRY CENTER, VMD 

3 +20 +20 +35.9 LEFF OF BELT 8 POWER CABLE 

+24 +20 +39.9 ADJACENT TO 8 Rl WT OF BELT 

+I3 +20 +28.9 TRACK CENTER 

+I4 0 + 9.9 RIGHT RIB PLANE 

+8 0 + 3.9 RIGHT BARRIER 

+ 8 +20 +23.9 LEFT OF BELT @ POKER CABLE 

+I5 +20 +30.9 ADJACENT TO L RIGHT OF BELT 

+ 3 +20 +18.9 TRACK CENTER 

+7 0 + 2.9 RIGHT RIB PLANE, VMD 

0 0 - 4.1 RIGHT RIB PLANE, HMO 

0 0 - 4.1 R I GHT BARR I ER 

+26 +20 +41.9 LEFT OF BELT @ POWEi? CABLE 

+I7 +20 +32.9 ADJACENT TO 8 RIGHT OF BELT 

+ 3 +20 +18.9 TRACK CENTER 

+8 0 + 3.9 RIGHT RIB PLANE 

+I2 0 + 7.9 LEFT OF BELT @ POWER CABLE 

+5 0 + 0.9 ADJACENT TO 8 RIGHT OF BELT 

-4 0 - 8.1 TRACK CENTER 

NM-25 #2 WON'T WORK ON -20 DB SCALE 

+I7 +20 +32.9 LEFT OF BELT @ POWER CABLE 

+I0 +20 +25.9 ADJACENT TO 8 RIGHT OF BELT 

+I7 0 +12.9 TRACK CENTER 

-.I 0 - 5.1 RIGHT RIB PLANE 

+24 0 +19.9 LEFT OF BELT & POWER CABLE 

+28 0 +23.9 ADJACENT TO AND RIGHT OF BELT 

+22 0 +17.9 TRACK CENTER 

+6 0 + 1.9 RIGHT RIB PLANE 
NORTH MA1 NS ( CONT. ) 

- STAT I ON - RAW DATA REDUCED DATA - NOTES 

7f +I6 +20 +31.9 LEFT OF BELT @ WWER CABLE 

+I3 +20 +28.9 ADJACENT TO 8 RIGHT OF BELT 

+ 4 +20 +19.9 TRACK CENTER 

8 +I0 0 + 5.9 ENTRY CENTER BEYOND TRACK END 

TEST #4 2890 KHZ WITH 0.3 AMP INTO TX ANTENNA ( NIA = 0.35 0 RX ANTENNA BAND 4 

USING HIGH FREQUENCY TUNER, REWCED DATA NOWALIZED TO NIA = 2.5 

SOUTH MAINS 

TAG ADJACENT TO BELT RIGHT RIB RIGHT BARRl ER 

LOCATION RAW DATA REDUCED DATA RAW DATA REDUCED DATA RAW DATA REWCED DATA 

5 1 +25 +40 +63.1 +I5 +40 +53.1 

68 +25 +40 +63.1 +I0 +40 +48.1 

76 +25 +40 +63.1 + 7 +40 +45.1 

l I0 +I5 +40 +53.1 + 3 +40 +41.1 

132 + 8 +40 +46.1 +I8 +20 +36.1 

NORTH MAINS 

STAT l ON - RAW DATA 

2 +I8 +60 

+20 +40 

+20 +20 

+I7 +20 

+I 1 +40 

+ 7 +40 

+I2 +20 

+I8 0 

+20 +20 

+I6 +20 

+ 3 +20 

+I I 0 

REDUCED DATA 

+76.1 

+58.1 

+38.1 

+35.1 

+49.1 

+45.1 

+30.1 

+16.1 

+38.1 

+34.1 

+21.1 

+ 9.1 

- NOTES 

LEFT OF BELT @ POWER CABLE 

ADJACENT TO 8 RlGHT OF BELT 

TRACK CENTER 

RIGHT RIB PLANE 

LEFT OF BELT @ POWER CABLE 

ADJACENT TO 8 RlGHT OF BELT 

TRACK CENTER 

RIGHT RI E PLANE 

LEFT OF BELT @ POWER CABLE 

ADJACENT TO 8 RlGHT OF BELT 

TRACK CENTER 

RIGHT RIB PLANE