5:1 Baluns/Ununs

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:

CU 5 1500 antenna - 5:1 Baluns/Ununs

Also available as a balanced output – CB-5-1500

FT240-3I, ID=1.4", AC/DC/Coax Noise Filter, RFI Range 1-300 MHz

F240-31-1
$9.99
In stock
1
Product Details
MPN: F240-31
Country/Region of Manufacture: China
RFI Range (MHz): 1-300 Mhz
ID-B (in/mm): 1.4/35.6
OD-A (in/mm): 2.4/61
Height-C (in/mm): .5/12.7
Weight (oz/gm): 188 grams
Initial permeability: 1500
Case/Box lot size: 100
Frequency (MHz)/Single turn impedance (ohms): 1MHZ: 12 ohms, 10MHz: 40 ohms, 25MHz: 63 ohms

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 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
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