5:1 CUBE™ Unun – Model CU-5-1500 (50:250 Ohm, 1.8-61 MHz, 1.5KW PEP)
Application. For traveling wave, end fed or portable 20-31 foot vertical antennas the 5:1 unun makes a good transformer for converting 50 ohm coax to a 250 ohm feed point. If you use the antenna on multiple bands, the feed point impedance may not always be 250 ohms and use of the unun at high (>350 ohms) or low (<100 ohms) will require reduced power input or the unun may have its power ratings exceeded and damage to the unun may occur. The (5:1 conversion ratio will change for loads other than 250 ohms unbalanced.
Typical application:
Also available as a balanced output – CB-5-1500
CUBE Feed Line Choke Unun, 5KW, 1.8-61 MHz, 20-38 dB Common Mode Rejection, Static Bleeder/Ground OptionProduct DetailsBrand: Palomar EngineersEffective Frequency Range (MHz): 1-61 MHzPEP Power Rating (watts): 5000Estimated Insertion Loss (db): .10Input Connector Type: SO-239 femaleOutput Connector Connector Type: SO-239 femaleGround Connector (Y/N): noneEnclosure Size (LxWxH inches): 4 x 4 x 25000 Watt rated 1:1 CUBE UNUN™
This higher power UNUN utilizes mil-spec coax cable for the windings on a extra large core toroid with coax silver shield and silver braid for low loss. The dielectric is Teflon® insulation for high voltage ratings of 1,900 volts. (A typical 5KW signal at 50 ohms impedance will have a voltage of 500 volts at 1:1 SWR). Wired as a UNUN (CU-1-5000) with SO-239 input and output connectors. Rated 5KW PEP/1500 Watts AM/RTTY/CW from 1.8-30 Mhz, less at 50 Mhz.
If you run RTTY contests or FT8 at 1500 watts output, this is the balun/unun you need – it won’t burn out at heavy 1500 watt duty cycles like other brands rated at 1500 watts (or more). We use these same chokes in our own RTTY station at full 1500 watts output and they have never failed. We use one at the amplifier output and another at each antenna feed point. Works very well on OCF antennas below the 4:1 balun to keep RF current on the antenna and off the feed line. Built like a tank, works like a charm, and priced under the competition – what more can you ask for? THIS IS OUR MOST POPULAR HIGH POWER UNUN!
Choose optional ground lug (on input connector shield) and static bleeder (on input connector center conductor) to bleed off static charges on a continuous basis. (Not a lightening arrestor)
5000 Watt rated 1:1 CUBE UNUN™
This higher power UNUN utilizes mil-spec coax cable for the windings on a extra large core toroid with coax silver shield and silver braid for low loss. The dielectric is Teflon® insulation for high voltage ratings of 1,900 volts. (A typical 5KW signal at 50 ohms impedance will have a voltage of 500 volts at 1:1 SWR). Wired as a UNUN (CU-1-5000) with SO-239 input and output connectors. Rated 5KW PEP/1500 Watts AM/RTTY/CW from 1.8-30 Mhz, less at 50 Mhz.
If you run RTTY contests or FT8 at 1500 watts output, this is the balun/unun you need – it won’t burn out at heavy 1500 watt duty cycles like other brands rated at 1500 watts (or more). We use these same chokes in our own RTTY station at full 1500 watts output and they have never failed. We use one at the amplifier output and another at each antenna feed point. Works very well on OCF antennas below the 4:1 balun to keep RF current on the antenna and off the feed line. Built like a tank, works like a charm, and priced under the competition – what more can you ask for? THIS IS OUR MOST POPULAR HIGH POWER UNUN!
Choose optional ground lug (on input connector shield) and static bleeder (on input connector center conductor) to bleed off static charges on a continuous basis. (Not a lightening arrestor)