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
Kurt Speaks Out - Digital PDF Version - Download Now!Product DetailsMPN: KSO-PDFKURT SPEAKS OUT - Digital PDF Version
Kurt's masterpiece contains 50 of Kurt Sterba's Kolumns from World Radio (1990 to 2006). 140 pages packed with sage advice, unusual antennas, and ham radio myths to avoid. Read, learn, and enjoy.
Included are unusual antennas: CCD, T2FD, OCF, Rattail Ver-Tee, G5RV, ZEPP, Loops and many others. Find out the real truth about antennas and STOP WASTING YOUR TIME and MONEY trying to get the lowest SWR! Download your copy and get educated by one of the experts – Krusty ole Kurt!!
Kurt N Sterba, sometimes known as “Krusty Olde Kurt” or “The Krusty One” and often as “The Masked Avenger”, is fearless in exposing antenna manufacturers who lie or use deceptive numbers to inflate the gain dB’s of their antennas. He also deflates those who use “new scientific breakthroughs” to explain the operation of their products. He pieces through the obfuscation of on-the-air antenna “experts” by explaining antennas, grounds, and feed lines in non-mathematical, simple English. His aim is to see that all understand the real basics of antennas, and are not taken in by the ever-prevalent, fine-sounding ad writers and other purveyors of false information.
Kurt wants you to know that downloading this work of art also entitles you to a free membership in KURTSKLUB, special product discounts, his oh-so-smart newsletter when he gets around to writing it, and more sage advice in his future books. You agree to keep your email box open, your mind free from commercial marketing hoop-la and let Kurt be your guide. Oh yea, spread the word, we need more members who seek true enlightenment like you!
Table of Contents
- THE CRUEL WORLD OF ANTENNAS. 5
- BROADBAND ANTENNAS. 8
- dB, dBi, dBd, ---- WHICH ONE IS RIGHT?. 12
- SMALL LOOPS REVISITED.. 15
- THE TRUTH ABOUT VERTICALS. 18
- GAIN AND FRONT-TO-BACK RATIO.. 21
- A GOOD, CHEAP. SMALL HF ANTENNA.. 24
- ALL ABOUT COAX.. 27
- THE TRUTH ABOUT LOOP ANTENNAS. 30
- 450 OHM LINE IS NOT 450 OHMS. 33
- DIPOLES AND DOUGHNUTS. 36
- THE “J” POLE.. 38
- 18 dB IS A MINOR DIFFERENCE?. 40
- TWO TYPES OF HAMS. 45
- ANTENNA TUNERS. 47
- WHICH SWR IS BETTER.. 50
- THE DOCTOR IS IN.. 52
- THE G5RV ON TWENTY METERS. 55
- KURT IS PREDJUDICED, NOT!57
- KURT REPEATS HIMSELF. 60
- IN WHICH THE MASKED AVENGER STRIKES. 63
- VERTICAL ANTENNAS AND SWR.. 66
- KURT STRIKES BACK.. 68
- THE RESONANT FEED-LINE DIPOLE.. 71
- MORE ABOUT RADIALS. 74
- KURT WRONG?. 76
- KURT’S 160 METER VERTICAL.. 78
- CLARIFICATION.. 80
- COILED CHOKE.. 83
- SHUNT FED VERTICALS. 86
- NEW ANTENNA BOOK.. 89
- LOW BAND – HORIZONTAL LOOP OR VERTICAL.. 91
- WHAT HAPPENED TO THE ZEPP?. 93
- THE T2FD ANTENNA.. 95
- USING A TUNER WITH A MOBILE INSTALLATION.. 97
- RESONANCE.. 99
- TOO COMPLICATED.. 101
- RAI vs M2103
- ANOTHER FANTASTIC ANTENNA.. 106
- RAI vs M2CONTINUED.. 108
- MATH PROBLEM... 110
- DANGER!112
- SWR CHANGE.. 114
- BALUNS – WHAT DO THEY DO?. 118
- CURRENT METER.. 120
- ANTENNA GARBAGE.. 122
- 160 METER VERTICAL.. 124
- OVER AND OVER.. 126
- THE RAT TAIL ANTENNA.. 129
- SWR.. 131
- EFFECT OF GROUND.. 133
- 1:1 or 4:1 BALUN?. 135
- Non-Resonant vs. Resonant Antennas. 137
- My Station Causes RFI – What do I do?. 139
- My Station is a VICTIM of RFI – What do I do?. 140
This version is published by Palomar Engineers, Inc.
KURT SPEAKS OUT - Digital PDF Version
Kurt's masterpiece contains 50 of Kurt Sterba's Kolumns from World Radio (1990 to 2006). 140 pages packed with sage advice, unusual antennas, and ham radio myths to avoid. Read, learn, and enjoy.
Included are unusual antennas: CCD, T2FD, OCF, Rattail Ver-Tee, G5RV, ZEPP, Loops and many others. Find out the real truth about antennas and STOP WASTING YOUR TIME and MONEY trying to get the lowest SWR! Download your copy and get educated by one of the experts – Krusty ole Kurt!!
Kurt N Sterba, sometimes known as “Krusty Olde Kurt” or “The Krusty One” and often as “The Masked Avenger”, is fearless in exposing antenna manufacturers who lie or use deceptive numbers to inflate the gain dB’s of their antennas. He also deflates those who use “new scientific breakthroughs” to explain the operation of their products. He pieces through the obfuscation of on-the-air antenna “experts” by explaining antennas, grounds, and feed lines in non-mathematical, simple English. His aim is to see that all understand the real basics of antennas, and are not taken in by the ever-prevalent, fine-sounding ad writers and other purveyors of false information.
Kurt wants you to know that downloading this work of art also entitles you to a free membership in KURTSKLUB, special product discounts, his oh-so-smart newsletter when he gets around to writing it, and more sage advice in his future books. You agree to keep your email box open, your mind free from commercial marketing hoop-la and let Kurt be your guide. Oh yea, spread the word, we need more members who seek true enlightenment like you!
Table of Contents
- THE CRUEL WORLD OF ANTENNAS. 5
- BROADBAND ANTENNAS. 8
- dB, dBi, dBd, ---- WHICH ONE IS RIGHT?. 12
- SMALL LOOPS REVISITED.. 15
- THE TRUTH ABOUT VERTICALS. 18
- GAIN AND FRONT-TO-BACK RATIO.. 21
- A GOOD, CHEAP. SMALL HF ANTENNA.. 24
- ALL ABOUT COAX.. 27
- THE TRUTH ABOUT LOOP ANTENNAS. 30
- 450 OHM LINE IS NOT 450 OHMS. 33
- DIPOLES AND DOUGHNUTS. 36
- THE “J” POLE.. 38
- 18 dB IS A MINOR DIFFERENCE?. 40
- TWO TYPES OF HAMS. 45
- ANTENNA TUNERS. 47
- WHICH SWR IS BETTER.. 50
- THE DOCTOR IS IN.. 52
- THE G5RV ON TWENTY METERS. 55
- KURT IS PREDJUDICED, NOT!57
- KURT REPEATS HIMSELF. 60
- IN WHICH THE MASKED AVENGER STRIKES. 63
- VERTICAL ANTENNAS AND SWR.. 66
- KURT STRIKES BACK.. 68
- THE RESONANT FEED-LINE DIPOLE.. 71
- MORE ABOUT RADIALS. 74
- KURT WRONG?. 76
- KURT’S 160 METER VERTICAL.. 78
- CLARIFICATION.. 80
- COILED CHOKE.. 83
- SHUNT FED VERTICALS. 86
- NEW ANTENNA BOOK.. 89
- LOW BAND – HORIZONTAL LOOP OR VERTICAL.. 91
- WHAT HAPPENED TO THE ZEPP?. 93
- THE T2FD ANTENNA.. 95
- USING A TUNER WITH A MOBILE INSTALLATION.. 97
- RESONANCE.. 99
- TOO COMPLICATED.. 101
- RAI vs M2103
- ANOTHER FANTASTIC ANTENNA.. 106
- RAI vs M2CONTINUED.. 108
- MATH PROBLEM... 110
- DANGER!112
- SWR CHANGE.. 114
- BALUNS – WHAT DO THEY DO?. 118
- CURRENT METER.. 120
- ANTENNA GARBAGE.. 122
- 160 METER VERTICAL.. 124
- OVER AND OVER.. 126
- THE RAT TAIL ANTENNA.. 129
- SWR.. 131
- EFFECT OF GROUND.. 133
- 1:1 or 4:1 BALUN?. 135
- Non-Resonant vs. Resonant Antennas. 137
- My Station Causes RFI – What do I do?. 139
- My Station is a VICTIM of RFI – What do I do?. 140
This version is published by Palomar Engineers, Inc.
