102 FT LADDER LINE FED DIPOLE

[ve6pg]

HI FROM TIM..I WOULD LIKE YOUR THOUGHTS ON A 102 FOOT,450 OHM LADDER LINE FED DIPOLE...I'M THINKING OF PUTTING ONE UP,TO BE ABLE TO GET MY BAND-WIDTH,GREATER,THRU THE TUNER. I KNOW ANTENNAS CAN BE A SOURCE OF DEBATE,AND I WELCOME THAT. I WOULD LIKE TO OPERATE MOST BANDS,SOME GUYS SAY IT WILL WORK ON 160,BUT I'M NOT SURE ABOUT THAT,BEING IT WOULD BE TOO SHORT. SO,IF YOU HAVE SOME INPUT,PLEASE LET ME KNOW. THIS WOULD INCLUDE ANY THOUGHTS ON VARIATIONS..
   TNX...TIM...

[Steve - WB3HUZ]

It should work FB with a good tuner. Whether is yields any more bandwidth depends on your tuner, the length of the feedline and local conditions (height above ground, soil conductivity, etc).

I would suggest using the 3/8 wavelength total length rule for the lowest desired frequency. Your 102 foot antenna will work on 160. But it will only work well with a strapping, low-loss tuner and heavy conductor open-wire line. Otherwise, losses will kill your signal.

If you have room, go with the longer antenna.

[WD8BIL]

Hi Tim...... If at all possible stay away from the T match to internal balun type tuners so revered by Amateurs. The can quickly degenerate into Hi pass networks causing all kinds of headaches. Plus the circulating currents in the inductor can get quite high.

If you can .... build up a true balanced tuner ala K1JJ !!!
Tried and true ... just for you !

Simple Balanced Tuner

[K1JJ]

Hi Tim,

Yep, Buddly and Steve are right on, bro!

Ideally, get the 102' or whatever length you can make it up as high and FLAT as possible, in the CLEAR. Use #12 or #10 insulated wire from Home Depot for the flat top. Then use the same heavy wire to make open wire spaced 3"- 6" apart. [spacing not critical]

This system will put out a great signal with very low loss on any band, despite the high current/low impedance points on the various bands. Forget the commercial "balun" type tuners and build up the simple one mentioned by Buddly.

You cannot do much better than this unless you use separate coax fed dipoles for each band to maintain a figure 8 dipole pattern or go to driven or Yagi arrays.  If you get the flat-top up at least 35' high, you will be as loud as any similar powered station using a full sized dipole on 160/75M.  [within a db locally]   ANd, even have some gain on 40M broadside, and a clover leaf pattern on 20M, an octopus on 10M. Separate dipoles on 20-10M are a better bet to keep the pattern textbook figure 8.

73,
Tom, K1JJ

[WA1GFZ]

Try hanging vertical sections off the ends to increase the total length
This may reduce losses.

[ve6pg]

OK...SOUNDS FB..WELL,I'M PERPLEXED AT TO WHAT TO DO..THE REASON THIS CAME UP,WAS,I HAVE A COMMERCIAL TRAP DIPOLE I WON AT A HAMFEST...75/40M. IT IS SURPRISING NARROW,MORE ON 40 THAN 75..I CAN RUN IT THRU A TUNER,BUT THE TUNER REALLY SOAKS UP THE RF. THE LENGTH OF IT IS 110FT. OK,HERE IN ONTARIO,ALOT OF OUR AM GANG HANG OUT ON 3725KC,AND THE TUNER WILL NOT TUNE ABOVE 3800KC. SO I USE MY WIRE(190 FT,END FED),FOR ALL MY 75M WORK. SINCE I DONT LIKE THE TRAP DIPOLE,AND IT WILL BE COMING DOWN,I WAS THINKING ABT A REPLACEMENT,HENCE THE IDEA OF THE WIRE DIPOLE W/450 LINE. SO,NOW I'M WONDERING ABOUT A END FED ZEPP,450 LINE FEED. THE WIRE WOULD BE ABT 150FT LONG..SO NOW I HAVE TO DECIDE EITHER A DIPOLE,OR END FED ZEPP...YOUR THOUGHTS..  TNX ....TIM....SK..

[K1JJ]

Center fed, HEAVY #10 homebrew openwire feedline - lose the 450 ohm plastic line and lose the tuner - build a tuner with no baluns.

Reread the previous posts.

I received your email and can FAX you the tuner schematic if you gve me a FAX #.

73,
T