Tube Feed Line Chokes

50:450 ohm (9:1) CUBE™ Unun, 1.8-31 MHz, 5 KW PEP, End Fed Antenna

SKU CU-9-5000
$149.95
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50:450 ohm (9:1) CUBE™ Unun, 1.8-31 MHz, 5 KW PEP, End Fed Antenna
Product Details
Input ohms/Output ohms: 50 in / 450 out
Frequency Range < 2:1 SWR (MHz): 1-31 MHz
PEP Power Rating (watts): 7500

Model CU-9-5000 is a 9:1 multi-core unun housed in a NEMA enclosure box (4″ x 4″ x 2″) with top stud/eyebolt output used to translate a 50 ohm input up to 450 ohms at RF power levels up to 5000 watts PEP (SSB) when used with a matched load. Usable to 61 MHz under 2:1 SWR with matched load.

Great for end fed antennas - FT-8 and digital mode power ratings are approximately 30% of PEP ratings into a matched 450 ohm load. For non-resonant end fed antennas, you will need a feed line choke on the coax. See typical antenna configuration notes below for details.

Non-Resonant End Fed Antenna Configuration Notes
TUBE feed line chokes/Line Isolators are used to suppress common mode current carried on the outside of the  coax braid which is often responsible for receiver noise and RFI in the receiver/transmitter. These chokes are very useful for suppressing RFI common mode current at the antenna feed point, at 1/4 wavelength intervals along the coax feed line and also at the entrance to the radio station.  They are available with various input and output connectors so as to conveniently connect to standard output connectors already installed on your feed line.

Palomar Engineers TUBE feed line chokes are designed to have 2-5 times more choking impedance over a broader frequency range than competitor units in similar packaging.  Each choke has the choking impedance and effective frequency range on the product label so you can choose the product best suited for your application.