Television digest with electronics reports (Jan-Dec 1954)
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Immediately After June 30, 1956
db above
Approximate
db above
f
Approximate
Frequency
Distance
1 uv/m (dbu)
uv/m
1 uv/m (dbu)
3
uv/m
10-157 kc
1000'
20 log-— -i 23.5
^ kc
(157/Fk,) X 15
oo 1 157
20 log-E^ kc
+
23.5
(157/F^,)
X 15
157-1600 kc
100'
20 log-15Z2 + 23.5
(1570/Ft^) X 15
20 log
+
23.5
(1570/F^,)
X 15
Fkc
Fkc
1.6-27.5 me
100'
24
15
24
15
27.5-70 me
100'
30
32
26
20
70-130 me
100'
34
50
30
32
130-174 me
100'
34-44*
50-150
30-38
32-80*
174-260 me
100'
44
150
38
80
260-470 me
100'
44-54’
150-500
38-46
80-200®
470-940 me
100'
54
500
46
200
940-1700 me
100'
58
800
52
400
above 1700 me 100'
62
1260
56
630
E =20 log
F
— 8.
= Measured i
n accordance
with, or equivalent to.
applicable
dbu
10
me
methods of the Institute of Radio Engineers. ' Use linear interpoiation between 50 and 150 microvoits per
® As an alternative to the provisions, the Commission is con meter for frequencies between 130 and 174 me.
sidering using the following formula for frequencies of 40 me Use linear interpolation between 150 and 500 microvolts per
and above: meter for frequencies between 260 and 470 me.
15.5 Information Concerning Apparatus: Upon request by the Commission the owner or operator of any device which is required by the provisions of this part to be certified, shall promptly furnish the Commission with such information as may be requested concerning the operation of such equipment, including a copy of any field intensity measurements made by or for the user in determining that radiation complies with the limits specified in this part.
15.6 Interference From Incidental and Restricted Radiation Devices: No incidental or restricted radiation device, irrespective of whether it otherwise operates in accordance with the provisions hereof, shall be operated in a manner which causes harmful interference to any licensed radio service. Where harmful interference is in fact caused by the operation of any such device its operation must cease immediately until the condition responsible for such interference has been eliminated.
Subpart B — Operation of Restricted Radiation Devices That Require Certification
15.101 Certification of equipment: The owner or operator of a restricted radiation device which requires certification under this subpart shall have posted in the room in which such equipment is operated, a certificate of a competent engineer setting forth the general conditions under which such equipment should be operated and certifying that the equipment involved is capable of complying with the radiation limits set forth in this part as applicable to such equipment. The certification required by this section shall describe with certainty the equipment covered thereby and a brief, but specific statement of the engineering tests upon which such certification is based and the results thereof.
15.102 Renewal of Certification: No regular renewal of certification is required. However, the certification required by Section 15.101 shall be renewed for particular equipment by such date as the Commission may specify if the Commission has reason to believe that the operation of such equipment may be inconsistent with the provisions of this subpart or a source of interference to authorized radio services.
15.103 Carrier Current System Operating in the Range 10-425 kc:
(a) Carrier current systems operating at frequencies between 10-425 kc may exceed the limit set forth in Section 15.4 provided the system is certified in accordance with Section 15.101 and provided further that the field intensity shall not exceed 1000 microvolts per meter for frequencies between 10 kc and 157 kc, and 250 microvolts per meter for frequencies between 157 kc and 425 kc at a distance greater than 1000 feet from any point in the system, and that radiation at distances greater than 500 feet from any point in any carrier current system operating under the provisions of this section and located within the 50 uv/m contour of a co-channel authorized station, shall not exceed an intensity of 15 db below the prevailing field intensity of such co-channel station.
(b) As a precautionary measure to avoid interference to navagational service, carrier current operators should discuss proposed installations and changes in existing installations within the frequency bands allocated to the aeronautical and marine services with the field offices of the Civil Aeronautics Administration, the United States Coast Guard and the Federal Communications Commission.
(c) Carrier current systems that normally radiate for a period of less than one second duration at intervals of m.ore than one minute shall not be subject to the field intensity limitation and certification requirements set forth in this part.
(d) Spurious and harmonic emissions from carrier current systems shall not be in excess of the values specified in Section 15.4.
15.104 Carrier Current Systems Operating Above 425 kc.
(a) The following provisions shall be applicable after the effective date of these rules to all carrier current systems which operate on frequencies between 425-1605 kc for the purpose of distributing programs to more than one broadcast receiver, provided, however, that until June 30, 1955, existing carrier current systems in this band shall be required in the alternative to meet the radiation limit of 15 microvolts per meter at a distance from any radiating source of 157,000 feet divided by the frequency in kilocycles:
(1) Radiation shall not exceed an intensity of 40 uv/m at distances of 100 feet or more from any radiating source, provided, however, that such radiation shall not exceed 15 uv/m at the border of the property exclusively under the control and for the exclusive use of the owner and operator of the system.®
(2) The carrier frequency on which the system operates shall be and odd multiple of 5 kc, and the system shall not deviate more than plus or minus 100 cycles from the carrier frequency.
(3) The system shall be certified in accordance with the provisions of Section 15.101.
(b) Carrier current systems, including wired television distribution systems, used for the purpose of distributing programs to broadcast receivers at frequencies above 1600 kc, shall be certified in accordance with Section 15.101. Such systems installed after the effective date of these rules shall not radiate in excess of 10 microvolts per meter at a distance of 10 feet or more from any point in the
“ Where persons other than the owner or operator of the system control or have the use of a portion of the property in question, the radiation limit shall be 15 uv/m at the border of that portion of the property, unless such persons have agreed In the contract or agreement providing for their use or control to accept any Interference from the system, or they have agreed in writing to the operation of the system.
I