50:200 (4:1) CUBE™ Unun, 1.8-61 MHz, 1500/5000 Watts PEP, End Fed, Vertical, Monopole

Name: 50:200 (4:1) CUBE™ Unun, 1.8-61 MHz, 1500/5000 Watts PEP, End Fed, Vertical, Monopole
Brand: Palomar Engineers
SKU: CU-4-1500
Price: 109.95 USD
Availability: InStock

Store/Antenna Products/CUBE Impedance Transformers (<1:1, 1:1, >1:1)/50:200 ohm (4:1) Transformers

SKU CU-4-1500

$109.95

Bulk pricing available for quantities of 2 units or more

Power Rating (PEP)

1500 Watt PEP (1.8-61 MHz)

5000 Watt PEP (1.8-31 MHz)

5000+ Watts/ 4KW continuos (1.8-31 MHz)

Quantity:

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Quantity	Price per item	Discount
2 items	$99.95	9% off
10 items	$94.95	14% off
50 items	$89.95	18% off
100 items	$79.95	27% off

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50:200 (4:1) CUBE™ Unun, 1.8-61 MHz, 1500/5000 Watts PEP, End Fed, Vertical, Monopole

Store/Antenna Products/CUBE Impedance Transformers (<1:1, 1:1, >1:1)/50:200 ohm (4:1) Transformers

Product Details

Input ohms/Output ohms: 50/100-400

Frequency Range < 2:1 SWR (MHz): 1.8-61 (1.5KW), 1.8-31 MHZ for 5000/5000HD

PEP Power Rating (watts): 1500/5000

Insertion Loss (dB): .15

Input Connector: SO-239

Output Connector(s): Wingnut/Eyebolt

Transformer Topology: Broadband Ferrite

Hardware Type: Stainless

Enclosure Size: 4" x 4" x 2"

Antenna Compatability: verticals, slopers, monopoles

Purpose. The CU-4-1500 is used as a 4:1 (200 ohm unbalanced load to 50 ohm unbalanced source) broadband transformer for 50 ohm coax cable rated at at 1500 PEP into 200 ohms unbalanced load from 1.8-61 MHz. Excellent for 43 foot verticals and also slopers (51', 85' or 119" work great)

USE: The top connector is for the 200 ohm unbalanced output, and the side connector is for a ground rod or radial connection.The SO-239 input connector shield/ground is shared with the ground connector.

For best results use a feed line choke between the CU-4-1500 and the coax input to isolate the coax from becoming part of the antenna. Our Maxi-Choker (MC-1-3000) is an excellent companion for this unun.

The CU-4-1500 is also useful for end fed OCF antennas utilizing a 4:1 unun and a coax feed line choke to set the antenna length for the "short" side of the OCF.

CU-4-5000 is in a 4" x 4" x 2" NEMA enclosure and weighs 3 pounds and is specified for 1.8-31 MHz - rated at 5KW PEP

CU-4-5000HD is in a 4" x 4" x 4" NEMA enclosure, contains 50% more ferrite cores then the 5000 and weighs 4 pounds and is specified for 1.8-31 MHz - rated at 4KW continuous duty, 5K+ PEP

When considering solutions for AM broadcast (550 Khz – 1.8 Mhz) you should consider Mix 77 ferrites available in a variety of shapes and sizes. Choose a size to give the maximum number of turns of the affected wire or cable.

AM broadcast transmits on a low frequency with large antennas. Consequently it takes a large antenna to receive the signals. Typical “antennas” are AC house wiring, phone lines, long satellite or cable TV cables, DSL/CAT5 lines running between rooms, etc. The device wires that connect to these “antennas” need to be choked with as many turns through the ferrite as possible. Some installation examples are shown below on this page.

For AC/ DC power cords and coax cables the F240-77 (2.4″ OD, 1.4″ ID) “Donut” toroid is the most popular. Also available are smaller toroid donuts and Mix 77 beads. Shown below is a graph with 8, 10, and 12 turns through the toroid – obviously more turns has higher choking impedance. Mix 77 toroid products are HERE and Mix 77 small beads (for small wires) are HERE

F240 77 Turns Comparison 1024x648 - AM Broadcast RFI Kits

F240-77 Turns Comparison from .1 – 8.1 Mhz

Shown below is a graph of frequency response verses choking magnitude for a F240-77 in the AM Broadcast band for a 12 turn coil around the toroid. (Same info as above but different frequency range).