What do you mean by linear loading? How long are your radials? 73, Petronel YO8SEP
On 21 Dec 2016 22:43, "Patrick Armstrong" <ft92...@gmail.com> wrote: > I have noticed several times that people talk about being able to put > up a full .250 wavelength vertical and I have wondered why almost never do > they think about making it .270 wavelength instead of .250 wavelength. The > little extra length gives a feed point impedance of 52 ohms with some > inductive reactance which can be canceled with a series capactor. This > gives a more efficient feed than a .250 wavelength and using an inductor to > get a match. I designed my 75/80m vertical this way and with 65 radials ( > odd number 'cause that's all the wire I had) it has allowed me to work 280 > entities with100 watts, all SSB. (Blasphemy I know, I have an ear > condition which made 13 wpm almost impossible for me). > > I also use this antenna on 160m by using linear loading and an inductor > for matching. Linear loading seems to be overlooked in a lot of discussions > of antennas on this list and I wonder why. Am I missing a downside to these > matching systems? If so I would like to hear about it. > > Pat Armstrong KF5YZ Heart of Texas > > On Tue, Dec 20, 2016 at 12:00 PM, W0MU Mike Fatchett <w...@w0mu.com> > wrote: > >> https://www.dxengineering.com/search/product-line/dx-enginee >> ring-160-meter-thunderbolt-vertical-antennas?autoview=SKU& >> keyword=160%20vertical&sortby=BestKeywordMatch&sortorder=Ascending >> >> >> On 12/20/2016 10:24 AM, Petronel Postolache wrote: >> >>> I can't find the Vertical from DX Engineering. If you can send me a link >>> it will be great. >>> One solution might be top hat vertical, similar with >>> http://dl2kq.de/ant/3-1.htm . Not sure how much power is lost in the >>> matching unit L1, C1. >>> >>> I would love a Waller Flag too. Imposible to buy one from here (too >>> expensive) but I might wanna try build one. Preamp will be the biggest >>> problem. >>> >>> Petronel >>> YO8SEP / YP8W >>> >>> On Mon, Dec 19, 2016 at 9:30 PM, W0MU Mike Fatchett <w...@w0mu.com >>> <mailto:w...@w0mu.com>> wrote: >>> >>> Check out DX Engineering. They sell a vertical that uses 3 top >>> hat wires. Sloping back down is ok. For 80/160 you need to stop >>> the 80m energy with a coil/trap My 80 uses a very fast taper and >>> the top is only 3/8 inch or less so It cannot support a coil or t >>> wires. I probably should have planned that out better. I was >>> also going to try to phase two 80 elements over time but that will >>> not happen any time soon. >>> >>> With all the metal in the yard the AY loop may not work very >>> well. Waller Flag on the roof maybe. I would love one. >>> >>> W0MU >>> >>> >>> On 12/19/2016 12:24 PM, Petronel Postolache wrote: >>> >>>> I can try to put a 21-22m (68-70 foot) telescopic aluminium pole, >>>> made from pipes 2" to 1" diameter. >>>> It will be a bit too long for 1/4 on 80m. I can put a T top hat >>>> or run an InvL, but probably need to slope it from 70 foot to >>>> about 40 foot. What will be better ? and will I be able to >>>> match/use the antenna on 80m also ? >>>> >>>> About K9AY, I understood that the loop is influenced by close >>>> metal objects, and the property is full of wire fences, vineyard >>>> rows and other "metal" structures. That's why i was thinking >>>> about using some flag/loop at 10 feet or more above ground. >>>> >>>> 73, Petronel >>>> YO8SEP >>>> >>>> 160 and 80 will be difficult. Can you get another vertical up >>>> about 60 feet? You can top load that with a trap for 80 and have >>>> "t" wires at the top that also act as guy wires. You can also >>>> bottom load for 160 and maybe that will be good enough for you. >>>> Radials whatever you can do will help.An Inverted L with about >>>> 50ft of vertical will work ok....If you can keep the horizontal >>>> end up in the air around the same height or more. It doesn't >>>> sound like you have any tall trees to work with.For receiving I >>>> have been very impressed with a K9AP loop. 25 ft up and about 15 >>>> feet out at the corners. It does not take up much space and you >>>> can reverse the direction easily with a relay. A flag or pennant >>>> will work too. You can never have enough rcv or xmit antenna! HI! >>>> Welcome to the club! >>>> >>>> W0MU >>>> >>>> >>> >>> >> _________________ >> Topband Reflector Archives - http://www.contesting.com/_topband >> > > _________________ Topband Reflector Archives - http://www.contesting.com/_topband