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Reviews Categories | Antenna parts, accessories, incl. baluns, hardware, etc. | Sigma Communications Baluns Help

Reviews Summary for Sigma Communications Baluns
Sigma Communications Baluns Reviews: 1 Average rating: 0.0/5 MSRP: $(missing—add MSRP)
Description: Pre-cut trap dipoles, baluns, etc.
Product is in production.
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N4GG Rating: 0/5 Nov 7, 2005 10:51 Send this review to a friend
Poor Design  Time owned: 0 to 3 months
Buyers beware - there is nothing right about the current baluns from Sigma. I picked up a 1 year old Sigma trap 30/40 dipole recently - the first problem was with the specs. The web page says the antenna is rated for 3kW. The labels on the traps say they are rated at 600W. An email to the company asking the real rating got this reply: "Should be good for legal limit." What country - US (1.5kW) or UK (400W)?
Next - the balun was full of water. It had been up for a year at a friends house. There are no drain holes - its "sealed," but not potted. There are lots of spaces for the unit to breathe and collect moisture. If you own one - drill a hole in the bottom.
Worst of all: I used the balun on 80M, 1:1 SWR, at 1.5kW, and it shorted after a few minutes. I opened it up - the design is simply no good. Its a beads-on-coax design like most current baluns but there are not enough beads to do the job at 3.5 and 1.8 MHz. This leads to heating, even at 1:1 SWR. The coax is not teflon like it should be, its plain old RG-8X, foam dielectric, and it has very tight radius bends as it goes through the ferrite cores. When hot, the center conductor of foax dielectric coax will migrate and short to the shield at tight bend points. This has been learned over and over again by those making baluns and stubs, but apparently its news to Sigma.

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