160-20m LOG loop-on-ground - RadioReference.com Forums
2018年5月8日 · Gentle reminder - the "log" or "dog" is not a grounded antenna. But here's how to go wrong, and why the use of an isolated transformer balun is recommended: So you try proof of concept with a 4:1 autotransformer type balun that shares a ground. And you choke the heck out of the transmission line. BUT, your station itself is grounded near the shack.
EFHW 8010, hung as a inverted L - RadioReference.com Forums
2024年11月16日 · I have the endfed hanging as a inverted L, my transformer is about 24-30" off the ground and it is grounded there also, the wire goes vertical about 30-33ft and have the wire antenna is on a pulley, and goes the rest of the way across the back yard horizontal...the tail insulator is about 10-12ft from touching the tree limbs where the rope is ...
Long Wire Transformer / DIY Antenna - RadioReference.com Forums
2008年6月12日 · I decided that I needed to shield the wire going out of my house prior to the speaker wire. So...I grab an old mag mount CB antenna and cut off the cable. I run this cable into a PAL to P259 12" adapter which goes into the external antenna port on my E1XM. The other side of the cable I just splice into the speaker wire outside my window.
160-20m LOG loop-on-ground - RadioReference.com Forums
2018年5月7日 · PAR / LNR Precision EF SWL looks particularly well suited for the LOG, although one can make stuff themselves.. * The 45 feet of wire makes up 3 sides of the square. * Unjumper grounds 1 & 2 to make them separate. * Attach 15 feet of wire to antenna ground lug #2 to make up the 4th side of the square. Do not attach to the other end of loop.
Efhw antenna transformer build - RadioReference.com Forums
2022年12月18日 · I just assembled two more this week and am getting a little better match on 10m with 100pf over some 150s I was using in the past. The voltage rating is not that bad and you can get by with about 300v for a 100 watt transmitter and maybe 1kV for a 1500 watt transmitter when the transformer/antenna are used within the resonant bands.
160-20m LOG loop-on-ground - RadioReference.com Forums
2018年5月7日 · Pattern degradation from un-balanced open loop version: Quick answer: use a common-mode-choke right after the transformer on your feedline. EZnec predictions - I ran a horizontal "5th wire" off the loop about 100 feet long to simulate the common mode of a long transmission line. There isn't...
160 - 20m *END FED* dipole-on-ground - RadioReference.com …
2018年10月17日 · The normal DOG for 160-20m is simple dipole 36 feet of insulated wire( 18 feet each side) attached to an isolated 9:1 transformer, and choked at the feedpoint so as not to make your transmission line part of the antenna, destroying the pattern.
Detect transformer leakage with HF AM antenna airspy HF
2024年5月26日 · With the telescopic antenna collapsed, it's almost like using a metal detector. I can move it along building walls and find rough locations where power cables with RF noise on them reside. With the antenna extended, I can roam the neighborhood a spot problems as I approach power poles, bad transformers, poor electrical connections, etc.
Antenna Transformer Question | RadioReference.com Forums
2006年1月22日 · The balun transformer on my ST-2 Scantenna was damaged and I replaced it with a 75Ω --> 300Ω model from Radio Shack. Now it seems to not to hear as well. All antenna and coax connections are in good shape. I suspect the replacement may be a mismatched or defective transformer. Are there other specs for …
160-20m LOG loop-on-ground - RadioReference.com Forums
2018年5月7日 · Grounding is fine, as long as it is between the rig / rcvr and the galvanically isolated transformer. You don't want to ground between the isolator and the antenna. W0BTU has some pre-wound 9:1 Isolator/transformers for 50Z coax. Or 6.25:1 for 75 ohm cable. I've mentioned the Radiowavz 9:1 balun.