52-120 BT to 4 1/2" EIA adapter product photo Front View L
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52-120 BT to 4 1/2" EIA adapter


SPINNER adapters offer outstanding electrical and mechanical properties

Adapters are used to connect transmission lines with different interface sizes (so-called inter-type or between-lines adapter) or within one size but different interface genders (so-called within-type or in-line adapter).

SPINNER high frequency adapters are optimized for quality and performance and are designed for the lowest possible reflection factors. The outstanding electrical and mechanical properties, the simple installation and the high reliability make SPINNER high-frequency adapters one of the most efficient and cost-effective transition connectors on the market. Precision adaptors with RF quality grade 0 are available upon request.

The SPINNER 52-120 BT to 4 1/2" EIA adapter ensures optimal performance for signal transmission between transmitter and antenna in broadcast stations.

Outstanding RF characteristics, best possible passive intermodulation and VSWR

A 52-120 BT to 4 1/2" EIA adapter enables you to reliably transmit radio-frequency signals in the frequency range from DC to 860 MHz.

The adaptor offers a transition from interface 52-120 BT to interface 4 1/2" EIA. The connector has a straight direction.

With the flaring technique system (BT) the outer conductor tube is flared by using a SPINNER flaring tool. The different components are connected together with coupling elements. The electrical contact at the outer conductor is done via a metallic ring which is mounted on periphery of the insulation disc of the coupling element. The very stable connection ensures a high RF tightness and repeatable electrical length. The BT flaring technique system is provided for indoor application and is designed to handle the maximum RF power up to 860 MHz. Please take into consideration that for rigid lines inner supports are necessary depending on the wanted line length. The inner supports prevent the inner conductor from sagging.

Coaxial flange connectors, generally known as “EIA flanges”, are connected by a coupling element. The flange connector system complies with international standards EIA STD RS-225, 339 IEC, DIN EN 122150 and MIL-F 24044. The EIA flange connectors are excellently qualified suited for pressurized systems and for outdoor installations. 4 1/2" EIA connectors are used to link two elements of a rigid or semi-rigid high performance coaxial transmission line for radio frequency signals. Typically, these are operated in systems for very high power transmission (from kW to MW), e.g. in DAB, DVB or FM broadcast systems or in high-energy applications in research facilities (particle accelerator, plasmatron).

RF characteristics

Number of interfaces:
Interface type:
52-120 BT (50 Ω)
4 1/2" EIA (50 Ω) per IEC 60339-2
Interface direction:
Mounting type:
Frequency range:
DC to 860 MHz
Frequency band:
Band 4/5, Band 3, Band 1, Band 2
Cut-off frequency:
1.0 GHz (H11 mode)
Average power rating:
142 kW @ 100 MHz (at +40 °C ambient temperature)
93 kW @ 230 MH (at +40 °C ambient temperature)
48 kW @ 860 MHz (at +40 °C ambient temperature) 1)
Proof voltage rating:
22000 V
Proof voltage rating remark:
(at sea level (NN))
Insertion loss coefficient /100m:
0.22 dB @ 100 MHz (at +20 °C ambient temperature)
0.33 dB @ 230 MHz (at +20 °C ambient temperature)
0.63 dB @ 860 MHz (at +20 °C ambient temperature)

Mechanical characteristics

Weight, approx.:
4.06 kg
185.0 mm

Further remarks

• outer conductor system copper / copper-alloy
• easy assembly
• SPINNER flaring tool BN 511400 with Insert BN 511445 available
• PTFE insulation
• for indoor application
also 60.0 kW @ 860 MHz possible, in this case it is necessary to paint the rigid line with a black, heat resistant varnish
Customs tariff number:



Product data sheet – 528118 – CB-L-198-199-DS.pdf