Seems like a resonance in the balun. I'd connect the two ends of the balanced feed together, not using the balun, thus to form a 2 turn loop, couple it to the 259 being used as a dip meter and see wh
This link works. .. And yes some years ago I modified my 238 with the referenced caps. High power drife problem solved. 73 Bob, K4TAX -- Original Message -- From: "Mike, K9UW" <k9uw@wi-net.com> To: "
Hi Mike, WB8VGE Hope your surgery goes well for you. I have gone and still going thru issues with my inverted L on 160M like your having. How long is your antenna? Is it a dipole or Folded dipole? I
Hi Mike, WB8VGE Oh I all ways forget some things to say or ask. Does your antenna have traps? Is it fedd with open feed line or a single coax cable? Jim, K9TF -- Jim K9TF ____________________________
Hi Again Mike Read through the archives on this subject so I wrote down my thoughts on this and what I have tried. Extra feed line you can coil up before point of entry maybe 3 foot diameter. I had 4
Again another thought. Remove any baluns. At the antenna and feed line point of connections try 100pF cap across the feed line and see how it tunes. Try shorting your open line on the transmitter sid
Jim, The antenna is a doublet up 50 feet inverted vee style. It is feed with about 170 ish feet of 600 ohm open line. None of the couplers can find a tuning solution All other bands work fine Sent fr
Mike, About how long is each side of the doublet? (You may have already given this info in a previous post but I do not have it.) Marsh, KA5M Jim, The antenna is a doublet up 50 feet inverted vee sty
131 on each side Mike Bryce, WB8VGE _______________________________________________ TenTec mailing list TenTec@contesting.com http://lists.contesting.com/mailman/listinfo/tentec
Based on these numbers, the antenna should show resonance at about 1.8 MHz and the feedline should show resonance at about 2.75 MHz. Let me emphasize that these are resonance numbers are not anyway r
Diddling a bit more, the feed point Z of the antenna is projected to be around 20 to 25 ohms. The feed line is about 3/8 wavelength or about 135 degrees. I see nothing wrong with these values that mi
Please define what you mean by a "doublet." When I started in ham radio 58 years ago, that was a dipole made out of 300 ohm twin lead, with one side broken at the center and connected to another piec
Mike told us what he has. The ARRL Antenna Book defines "doublet" as synonymous with "dipole," but I understand many hams intend the locution "doublet" to refer to a type of dipole fed with open line
Bob mentioned one point that I would like to emphasize. 160m is a very difficult band to tune on the Model 238 (or similar). The reason is, the tuning is very sharp and the sweet point is a very tiny
Semantics. I learned yet another meaning of the word doublet. I think we agree that the word "dipole" alone means a half wavelength radiator, fed in the middle. We 300 Ohm is used as Jim described, I
Which is why I asked (twice) for a clarification. :) 73, Jim _______________________________________________ TenTec mailing list TenTec@contesting.com http://lists.contesting.com/mailman/listinfo/ten
Mike, Modeling your doublet with EZNEC+ ver 5.0.59 and making 3 assumptions: 1. The antenna is in a straight line 2. Each end slopes down from 50 ft to 10 ft above the ground 3. Freq 1.830 MHz EZNEC
Is your antenna a single wire dipole, Folded dipole, what? Trying to figure out your feed point impedance. Try placing a coil about 10 to 12 turns of #12 insulated wire between each half of your feed
bob, that's basically how I've been attacking the problem. set c @2 and L @30 apply some rf and move between HI Z to LO Z. When I find a spot that will result in a 2:1 swr, the L is still at 30 and t
bob, since the antenna is inverted vee style, the feedline slopes away from the tower. and yes, 5kw current 1:1 balun at the end feed into the 238 tuner. Mike Bryce, WB8VGE the heathkit shop SunLight