Coaxial cable is the most familiar
form of RF transmission line for most people these days. Up until 2009 when the
U.S. switched to digital television (DTV), there were still a fairly large number
of people who had the old 300 Ω twin lead cable running from roof-top
antennas to TV sets. Over-the-air reception has petered off precipitously since
then. Coaxial cable is undoubtedly more convenient and forgiving regarding routing
since proximity to structures - particularly metallic components - is less
sensitive than twin lead.
300 Ω twin lead cable (~70¢/foot today
for 100') used to cost less
than good quality 75 Ω RG−6 cable (~35¢/foot today
for 100'), but just a couple decades
ago when twin lead dominated, the opposite was true. What has not changed is the
insertion loss of 300 Ω twin lead cable is typically around 2 dB at VHF
TV channel frequencies (54-210 MHz), and 450 Ω ladder line (twin lead
on steroids) is about 1/2 or less of that (see "Loss Figures for 300 Ohm Twin Line"). Insertion loss on RG−59
coaxial cable is around 4 dB/100' in the same band (RG−6 is ~3 dB/100',
and RG−11 is ~2 dB/100'). The lower you go in frequency, the lower the loss
in both cable types, but twin leads gets better faster.
Federal Telephone and Radio Company Ad
North, East, South, West ...
Wherever there are TV customers ...
Federal has a lead-in for the finest VHD-UHF
Whatever the area or atmosphere ... city or fringe ... rain, snow ice, heat,
dust, salt spray, polluted air or radiation ... you'll find the answer in these
quality-controlled cables by Federal -
For Community TV it's Federal's "Big 5"
K-14 - 71-ohm shielded primary transmission line for community distribution systems.
Famous for lowest line loss, long cable runs and fewer amplifiers required. Capacitance:
21.5 mmf/ft. Attenuation DB 100/ft: .57-50 Mc; .90-100 Mc; 1.42-200 Mc; 2.3-400
RG-11/U - 7 5-ohm shielded low-loss coaxial. One of the best small-diameter cables.
Tops as a community TV secondary lead-in. Seven strands #26 tinned copper. Capacitance:
20.5 mmf/ft. Attenuation DB 100/ft: 1.5-50 Mc; 2.15-100 Mc; 3.2-200 Mc; 4.7-400
RG-59/U - 73-ohm coaxial TV lead-in cable. Highly efficient as a community system
pole-to-house tap-off. Meets all needs wherever a high-grade installation is a must.
Capacitance: 21 mmf/ft. Attenuation DB 100/ft: 2.7-50 Mc; 4.0-100 Mc; 5.7-200 Mc;
K-111 - 300-ohm shielded, balanced TV lead-in developed by FTR. Minimizes noise,
snow, ghosts due to transmission line pick-ups. Ideal for many areas where good
TV was impossible before. Capacitance: 4.2 mmf/ft. Attenuation DB 100/ft: 3.4-100
Mc; 6.6-400 Mc.
TV-1184 - 300-ohm dumbbell-shaped TV lead-in. A standard low-cost lead-in for
areas without unusual conditions. Cinnamon-brown color is highly resistant to ultra-violet.
Two conductors: 7/#28. Capacitance: 4 mmf/ft. Attenuation DB 100/ft: 1.28-100 Mc;
TV-1182 - 300-ohm deluxe type heavy-duty TV lead-in with 90 mil. web. Insulated
with "silver" polyethylene, Federal development that provides maximum weather protection
and long life. Capacitance: 4 mmf/ft.Attenu-ation DB 100/ft: 1.22-100 Mc; 2.85-400
Non-Radiating Lead-ins for Multiplex TV Systems
K-125 - 75-ohm coaxial TV lead-in cable. Double-shielded and jacketed. Formerly
listed as SP-75.
Use these 2 for Community TV radiation
K-126 - 73-ohm coaxial TV lead-in cable. Double-shielded and jacketed. Formerly
listed as SP-76.
K-125 alternates for·RG-11/U as secondary lead-in
K-126 alternates for RG-5S9/U as tap-off lead-in
... "Pipeline" of the Air!
300-Ohm All-Channel Twin-Lead that Laughs at Weather
For Fringe Areas
TV-1182 - Provides remarkably low line loss in fringe areas. Outstanding for
resistance to weather and sunlight. Silver-colored insulation blends with any color
scheme in home decoration.
K-200 (RG-86/U) - 200-ohm heavy-duty ultra low-loss lead-in. Particularly adaptable
to remote-area installations - especially long runs and multi-stack antennas. Also
used with rombics.
See your local Federal Distributor or write to Federal direct Dept. D-959
TV-1185's "Silver" pigmentation lets you
Install it and Forget it!
Federal's TV-1185 is virtually a "pipeline" for better-than-ever TV reception
... VHF or UHF. Insulated with the revolutionary Federal-developed "silver" polyethylene,
TV-1185 is amazingly tough, flexible and efficient.
TV-1185 leads in Weatherometer tests ... fights heat, resists moisture and other
destructive deposits ... minimizes deterioration due to sunlight.
TV-1185 keeps the energy field inside the weather-proof sheath ... providing
exceptionally low loss ... more constant impedance ... a better TV picture regardless
of area or length of lead. It's easy to install and tight-seal against all atmospheric
There's no finer tubular lead-in of its type on the market today!
Capacitance: 4 mmf/ft. Attenuation DB 100/ft: 0.5-10 Mc; 0.95-50 Mc; 1.25-100
Mc; 1.7-200 Mc; 2.6-400 Mc; 3.0-500 Mc; 4.5-1000 Mc.
Product of America's leading producer of solid dielectric coaxial cables
Federal Telephone and Radio Company
100 Kingsland Road, Clifton, N.J.
In Canada: Federal Electric Manufacturing Company, Ltd., Montreal, P. Q.
Export Distributors: International Standard Electric Corp., 67 Broad St., N.
Posted August 1, 2022
(updated from original post