I just wanted to mention it because the terms HAAT and EHAAT do come up now and then but a lot of folks do not know exactly what it means and think it is the same as height above ground which it is not.......usually.
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Question about dipoles ?
- Thread starter Oatmeal
- Start date
That's correct, but more for running a single band dipole. I believe the OP is asking about multiband dipoles in a limited space.
Since a lot of us don't have enough property or for other reasons can't run multiple mono band antennas for every band, we usually compromise by running a multiband antenna which in it self is a compromise antenna, Therefore antenna height is usually compromised too.
Most fiberglass pushup poles for dipole antennas are 45 ft. This is an acceptable compromise and considered a acceptable minimum height for Windom antennas since the verticle radiator is 15 meters.
So when using these types of antennas in a compromising fashion, the only pratical tuning is done with a tuner since there is no tuning device on the antenna itself.
The OP was also asking how to check these without an analyzer, Just plug in your coax and use a good SWR meter on each band and you can see where you may need to use a tuner. If you are running a modern HF rig, those SWR meters and built in tuners are good enough to go by for now.
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Hope you are doing OK!yeah, I realized that after I typed it soooooo, I just added in (height of the center support),.
I'm is a hospital on some serious meds, and,............. I just didn't feel like retyping it, doesn't make any sense NOW , but at the time of the post it seemed right
Any you guys have a long run, say a few 100 feet ?...
If so, what are you using and what antenna/dipole ?..
I used to have a long run of wire going up the mountain here......did I show you guys the wire I was using at the time ?...
If so, what are you using and what antenna/dipole ?..
I used to have a long run of wire going up the mountain here......did I show you guys the wire I was using at the time ?...
If your feedline is anywhere near that long, you need to seriously consider balanced parallel feeders - like homebrew ladder line, keeping the conductors around six - eight inches apart with good insulating spacers. We old-timers used wood dowels boiled (VERY CAREFULLY) in paraffin.
Yes......several times including the discussion about the fire that took it out IIRC. You referred to it as mountain line(?) and also IIRC it was CATV aluminax cable.
Reminds me of the customer that came back in complaining that the 3 X100 meter rolls of rg58 cu that he purchased was sh*t .When he joined them together to get his UHF ant up the hill he couldn't get any signal out even though he had a perfect SWR. Yes ladder line is the way to go,but even that has it's limits.
Yes ladder line is the way to go,but even that has it's limits.
That was some good wire, worked a lot of dx off it...it was tv cable wire 75 ohm stuff....
CK, thats what the guys here calls it mountain line ...
There's a guy here goes by stop sign, he's in the Beckley area, any you guys ever talked to him on 11m in dx?..
CK, thats what the guys here calls it mountain line ...
There's a guy here goes by stop sign, he's in the Beckley area, any you guys ever talked to him on 11m in dx?..
You guys who talks dx on channel 28, if you ever hear Stop Sign in there from WVa, ask him what he is talking on, and what he runs for a antenna, he has pics of his stuff on another cb site...
I'm dealing with antenna issues myself right now. Long story, but hit by a devastating eye disease and low vision now. Not sure if we'll stay here, so no big antenna support projects.
I'm experimenting with LOW antennas mounted on the house for now.
My take:
Coax fed 10 meter dipole, works and my Dentorn Super Tuner can match it to 20 through 10 meter. High noise floor, not the best transmit, though it DOES get out.
450 ladder line fed 40 meterish doublet (ish because the legs are a bit long and it wasn't trimmed to tune). The Dentron can match it to 80 through 10 meters. 80 actually works better than one would think. Lower noise floor than the dipole and better receive. Markedly better transmit it seems, even on 10 meter.
210' rectangular loop 450 ladder line fed. The Dentron can again match it to 80-10 meters. Lowest noise floor of the three, highest receive of the three, gets out about as well as the doublet, maybe slightly better.
Wire is cheap, if you really want to know if something works just try it!
Crossing the power line....of course, best not to for noise, performance and safety...however...sometimes you gotta do what you gotta do. I WOULD NOT cross over the high voltage lines on the poles!!! The high voltage lines look jacketed, but they're not, it's just a corrosion covering, it's not insulative! But, if it's just the drop coming from the pole to your house those lines ARE insulated. The two power lines are insulated and they're ran with a grounded stringer line that supports the wires to the house. If the jacket on them was compromised it'd probably be giving you trouble. So, if you cross that and touch it you're probably OK. If I were going to do that I'd use insulated wire for the antenna to boot. If in doubt, call the electric company. I did and I was told I need to keep an antenna three feet away and at a right angle to my house drop. They will for a fee shut the power down at the pole while I cross it, but the Tech said the drops are jacketed and if I used jacketed antenna wire to cross it'd be fine.
It sounds like four relatively high supports for a loop may not be feasbile for you, so I would go with the ladder line fed doublet (same length as a dipole, just ladder line fed).
I have a Dentron Super Tuner, look on QTH classifieds, fleaBay or CraigList (use adhuntr to search all of CraigsList easily - most people WILL ship small things), they can be had for $100 or less (I just picked up a Dentron Jr for $30 delivered, works GREAT on my antennas too, just won't handle as much wattage, it handles the rig fine though!). Using a tuner the doublet should work anywhere you want to go to. Trimming it and then working the harmonics will probably work, I just haven't went there yet.
To quickly and easily tune the Dentron I use an MFJ-207 antenna analyzer. It's crude and only tells you the resonant frequency coarsely as it's a knob pointer / printed scale for the frequency, but it's cheap new and cheaper used. It can be made to be very precise cheaply though, it has a frequency counter output and you can get a frequency counter and jumper coax off fleaBay for $20 shipped from China. Put the output of the tuner on a coax switch, switch to the MFJ, set your frequency and tune the Dentron for the lowest SWR, then switch to the rig and you're good to go.
Hope that helps...don't be put off by the naysayers, high and clear is no doubt best, but low and cluttered DOES work, it's better than nothing! Wire is cheap, so just give it a shot!
Steve KA0NEB
I'm experimenting with LOW antennas mounted on the house for now.
My take:
Coax fed 10 meter dipole, works and my Dentorn Super Tuner can match it to 20 through 10 meter. High noise floor, not the best transmit, though it DOES get out.
450 ladder line fed 40 meterish doublet (ish because the legs are a bit long and it wasn't trimmed to tune). The Dentron can match it to 80 through 10 meters. 80 actually works better than one would think. Lower noise floor than the dipole and better receive. Markedly better transmit it seems, even on 10 meter.
210' rectangular loop 450 ladder line fed. The Dentron can again match it to 80-10 meters. Lowest noise floor of the three, highest receive of the three, gets out about as well as the doublet, maybe slightly better.
Wire is cheap, if you really want to know if something works just try it!
Crossing the power line....of course, best not to for noise, performance and safety...however...sometimes you gotta do what you gotta do. I WOULD NOT cross over the high voltage lines on the poles!!! The high voltage lines look jacketed, but they're not, it's just a corrosion covering, it's not insulative! But, if it's just the drop coming from the pole to your house those lines ARE insulated. The two power lines are insulated and they're ran with a grounded stringer line that supports the wires to the house. If the jacket on them was compromised it'd probably be giving you trouble. So, if you cross that and touch it you're probably OK. If I were going to do that I'd use insulated wire for the antenna to boot. If in doubt, call the electric company. I did and I was told I need to keep an antenna three feet away and at a right angle to my house drop. They will for a fee shut the power down at the pole while I cross it, but the Tech said the drops are jacketed and if I used jacketed antenna wire to cross it'd be fine.
It sounds like four relatively high supports for a loop may not be feasbile for you, so I would go with the ladder line fed doublet (same length as a dipole, just ladder line fed).
I have a Dentron Super Tuner, look on QTH classifieds, fleaBay or CraigList (use adhuntr to search all of CraigsList easily - most people WILL ship small things), they can be had for $100 or less (I just picked up a Dentron Jr for $30 delivered, works GREAT on my antennas too, just won't handle as much wattage, it handles the rig fine though!). Using a tuner the doublet should work anywhere you want to go to. Trimming it and then working the harmonics will probably work, I just haven't went there yet.
To quickly and easily tune the Dentron I use an MFJ-207 antenna analyzer. It's crude and only tells you the resonant frequency coarsely as it's a knob pointer / printed scale for the frequency, but it's cheap new and cheaper used. It can be made to be very precise cheaply though, it has a frequency counter output and you can get a frequency counter and jumper coax off fleaBay for $20 shipped from China. Put the output of the tuner on a coax switch, switch to the MFJ, set your frequency and tune the Dentron for the lowest SWR, then switch to the rig and you're good to go.
Hope that helps...don't be put off by the naysayers, high and clear is no doubt best, but low and cluttered DOES work, it's better than nothing! Wire is cheap, so just give it a shot!
Steve KA0NEB
Have a question or 2...
As you no I have power lines in my yard, would I be better off with a dipole thats has insulation on the wire or will it matter?....
And if I went with a G5RV 10-80m full size 102', would it still perform as it should with the last 35ft of it turned in another direction?...
Or just go with a G5RV Jr, what do you guys recommend ?..
As you no I have power lines in my yard, would I be better off with a dipole thats has insulation on the wire or will it matter?....
And if I went with a G5RV 10-80m full size 102', would it still perform as it should with the last 35ft of it turned in another direction?...
Or just go with a G5RV Jr, what do you guys recommend ?..
Insulation on the wire will make no difference. Any RF noise will still get thru and God forbid thr antenna makes contact with the power lines but if it did that piddly insulation is not going to stop thousands of volts.
Then why did you ask about insulation on the wire when you mentioned that you had power lines in your yard?