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
F240-31, ID=1.4", AC/DC/Coax Noise Filter, RFI Range 1-300 MHz, AKA FT240-31Product DetailsMPN: F240-31Country/Region of Manufacture: ChinaRFI Range (MHz): 1-300 MhzID-B (in/mm): 1.4/35.6OD-A (in/mm): 2.4/61Height-C (in/mm): .5/12.7Weight (oz/gm): 188 gramsInitial permeability: 1500Case/Box lot size: 100Frequency (MHz)/Single turn impedance (ohms): 1MHZ: 12 ohms, 10MHz: 40 ohms, 25MHz: 63 ohmsVery useful for AC/DC power, coax cable common mode current suppression. For highest choking resistance, wrap cable through center of ring as many turns as possible. DO NOT use for impedance transformers (2:1, 4:1, 9:1, etc.) - use Mix 43 or Mix 61 for high power.
All F240-31 singles individually labelled with specifications for ease of identification.
Customer Feedback:
At 100 watts on 40 meters, my CW sidetone used to be the smoke detectors in my house! After installing a set of ferrite rings on the 120V and 12V lines, I can finally work 40 meters CW without hearing my code through the smoke detectors. Thank you!
Paul
K7SHR
On Sale
FT240-3I, ID=1.4", AC/DC/Coax Noise Filter, RFI Range 1-300 MHz, Case of 100FT240-3I, ID=1.4", AC/DC/Coax Noise Filter, RFI Range 1-300 MHz, Case of 100SKU F240-31-100List price $1,000.00 Save 21%$795.00On Sale
DC Voltage Common Mode Noise Filter - Marine, RV, Communications, 600 Volts/30 AmpsDC Voltage Common Mode Noise Filter - Marine, RV, Communications, 600 Volts/30 AmpsSKU RFI-DC-30List price $109.95 Save 18%$89.95On Sale
RG-8X Coax Jumper Cable with PL-259's on each end - 3 feetRG-8X Coax Jumper Cable with PL-259's on each end - 3 feetSKU RG-8X-3List price $19.95 Save 15%$16.95On Sale
FT240-3I, ID=1.4", AC/DC/Coax Noise Filter, RFI Range 1-300 MHz, Bulk Pack of 10FT240-3I, ID=1.4", AC/DC/Coax Noise Filter, RFI Range 1-300 MHz, Bulk Pack of 10SKU F240-31-10List price $100.00 Save 10%$89.95
Very useful for AC/DC power, coax cable common mode current suppression. For highest choking resistance, wrap cable through center of ring as many turns as possible. DO NOT use for impedance transformers (2:1, 4:1, 9:1, etc.) - use Mix 43 or Mix 61 for high power.
All F240-31 singles individually labelled with specifications for ease of identification.
Customer Feedback:
