How much taller would the iMax 2000 have to be to be able to operate at .64 wave and operate on as low as 20m maybe 30m. Since it is .64 for 11m on @27.000.00.
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Another IMAX 2000 question
- Thread starter Heavy Metal
- Start date
Do the math. A .64 wavelength for 20m is 300 ÷ 14 MHz x .64 = 13.71 meters or about 45 feet.
I understand that but if I change the mid and top sections what .64 calculation would I need to get .64 wave at in 20m to go 40m 60m 30m 20m 17m 15m ect like if stock out of box .64 = @26.750.00 and is usable without a tuner on 10m 11m 12m 15m and part of 17m, but it favors 11m for .64 want to favor 20m about center band @14.175. I hope I am relaying this right if anyone understands what I am seeking to do, also the top part that the mid section screws into that silver( chrome like ) cap, ode like to know we're to get those to put over fiberglass pipe or pic pipe to screw in like that. Any help will be appreciated on sites that have these things and ideas on what to do to accomplish this.
Thanks
Thanks
I'll be "gentile",........... if you have privileges on 14.175, you should know the answer already.
I'll be "gentile",........... if you have privileges on 14.175, you should know the answer already.
I was going to say that however I did not have my morning coffee at that point and I know I would have put it less gentile than you did.
I told you above. 300 divided by the frequency in mhz is the wavelenght in meters. Multiply that by .64 to get what you are looking for. If you want feet then use 936 divided by the frequency in mhz.
Forget about trying what you are talking about. It is obvious you do not understand antenna theory very well. You cannot simply take a .64 wave antenna for one band and extend it to make it a .64 wave on another band. There are matching components imbedded inside those antennas that need to be dealt with and they are frequency sensitive. What works for one band will not work for another band.You would be far better off with a vertical wire or pipe with the appropriate matching network at the base. Also there is no way that antenna will work 10-15m out of the box without an antenna tuner. If it does then it must be the most inefficient antenna on the market. SWR bandwidth, gain, and efficiency are three antenna factors and you can only optimise one at the expense of the other two.
I know a couple of locals that run the Comet CHA-250, and even though the company claimes it works 80-10, both guys say it barely works on 40 for them. 15 and 10 are ok, and 20 is so-so. The thing is only 22 feet long, I think!
If you're looking to use what you have, keep the Imax for 10 and 12 (I know you just got a tuner). Make a wire antenna for the low bands you are trying to hit. A dipole (or inverted V if you're space limited). You can droop dipole ends, too if you need to. I'm still learning this stuff myself, there are lots of books (ARRL) and even Hamsphere and other sites have a lot of other designs that might work well for you. I ended up with an end fed that really is too short, but it works, and I am able to work 75 with it. My delta loop is good for 40-10. I have found that the tried and true stuff is indeed "tried and true", and that's why so many people use them. They work! Stay away from all-bandlow swr no tuner snake oil antennas. They don't work... except to take money out of your wallet.
73,
Brett
If you're looking to use what you have, keep the Imax for 10 and 12 (I know you just got a tuner).
Make a wire antenna for the low bands you are trying to hit. A dipole (or inverted V if you're space limited). You can droop dipole ends, too if you need to. I'm still learning this stuff myself, there are lots of books (ARRL) and even Hamsphere and other sites have a lot of other designs that might work well for you. I ended up with an end fed that really is too short, but it works, and I am able to work 75 with it. My delta loop is good for 40-10. I have found that the tried and true stuff is indeed "tried and true", and that's why so many people use them. They work! Stay away from all-bandlow swr no tuner snake oil antennas. They don't work... except to take money out of your wallet.73,
Brett
I get things clicking in my head and all and seeing the iMax 2000 swr readings on 12m(24Mhz) - 29 being almost flat I wonder how the hell. And I get these what if's, also thought of side base coils. I am just trying to figure things I can and cannot do and laws I can't manipulate as well.
I know a couple of locals that run the Comet CHA-250, and even though the company claimes it works 80-10, both guys say it barely works on 40 for them. 15 and 10 are ok, and 20 is so-so. The thing is only 22 feet long, I think!
If you're looking to use what you have, keep the Imax for 10 and 12 (I know you just got a tuner).
73,
Brett
That CHA-250 has a rather lossy matching network in the base of it. The best advice I can give to someone looking for an all band antenna is to avoid the antennas that claim DC-daylight operation with no tuner or traps required and that includes the G5RV. A dummy load will have a great SWR from DC-daylight too but does not radiate very well. By contrast a 66 foot tall wire or mast will work GREAT on 80m but will have a relatively narrow SWR bandwidth and will be useless on other bands without a tuner.
It's not that I am seeking an all banded but having fun finding out and trying their are a few antennas I have seen that have caught my eye/attention but I was just thinking of messing with an imax 2000 for fun if you add a longer top section you still have to cut it to come back down it cut it to raise it up even into 6m ect. This is were my thought goes for stripping the top out and mid section and adding a few more feet for both bring it upto .64 somewhere in the 20m area maybe I am grasping at straws for fun but what the heck I got tons of bare cooper wire 14 12 10 to use inside it and some stranded 10 gauge electrical wire was seeking a balun/terminator resistor combination for a folded dipole but finding one that handles 5k again here comes why need so high. Answer just what I am seeking I see balums in that and 10kw why produce them lol. Anyhow I am just thinking out loud and seeing what everyone here may think about it. To me I need @4 to 5 antennas trying to do as little as possible I am limited space so up vertical becomes the way to go but a folded dipole horizontal maybe an alternative but I need omnidirectional more so for now.
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RatsoW8
Supporting Member, W9WDX ARC Member - WD8T
You might be able to make a 5/8 wave vertical out of it but you need to extend it out to about 42' and remove the matching components in the base. I'm no engineer but I'm pretty sure a 20 meter vertical like you want to build with no radial field will perform about as well as a dummy load and forget about working dx.
I have limited space so I built a very simple 1/4 wave 20 m vertical from a telescoping fiberglass fishing pole with a wire run through the center. It's painted dark brown and ground mounted, direct fed with an ugly balun, a home brew base plate and 32 radials hidden in the yard. It worked really well for dx contacts and sometimes better than my 20 meter dipole. I think I had about $25 in it.
My usable antenna width across the back yard is about 40 feet. The answer to my space problem is an OCF dipole. 40 through 6 meters, 66' total length so I have to bend the ends down at two different angles to fit the space and it's about 35 feet off the ground. It works great stateside and for DX. Even with the bends the antenna shows swr under 1:1.5 on 40,20 and 10 meters which are the bands I play on most often. Tunes up fine on other bands with my LDG AT600Pro autotuner.
When the weather warms up here I'll pull it down and do some maintenance and it's going back up this spring with a 10' vertical radiator coax section and line isolator. That should help it perform a little better for dx.
I have limited space so I built a very simple 1/4 wave 20 m vertical from a telescoping fiberglass fishing pole with a wire run through the center. It's painted dark brown and ground mounted, direct fed with an ugly balun, a home brew base plate and 32 radials hidden in the yard. It worked really well for dx contacts and sometimes better than my 20 meter dipole. I think I had about $25 in it.
My usable antenna width across the back yard is about 40 feet. The answer to my space problem is an OCF dipole. 40 through 6 meters, 66' total length so I have to bend the ends down at two different angles to fit the space and it's about 35 feet off the ground. It works great stateside and for DX. Even with the bends the antenna shows swr under 1:1.5 on 40,20 and 10 meters which are the bands I play on most often. Tunes up fine on other bands with my LDG AT600Pro autotuner.
When the weather warms up here I'll pull it down and do some maintenance and it's going back up this spring with a 10' vertical radiator coax section and line isolator. That should help it perform a little better for dx.
I thought of a 50' fiberglass push pole and put some plexi glass strips outwards upto 46' and downwards hard to find something go too much higher and stick it on a 16' 4x4 that will be out of ground so out of 16' 14' or 13' above so about 3' of the 50' fiberglass pushpole guide it too be quite a ways up.
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My head hurts. Spell checker and punctuation would make it a LOT easier to understand what you are trying to say and would allow us to better get an idea about what you are thinking.
If you are looking for a decent multiband antenna about the cheapest and best antenna going is a simple doublet fed with ladder line and fed thru a tuner and balun. Note I said BALUN. It is not a BALUM. A doublet fed with 450 ohm ladder line and anywhere from 51-66 feet on each side and erected as an inverted VEE will be pretty much omnidirectional, will work from 80-6m and will have gain on the higher bands.. Half that size will work very well for 40m and up. I am presently using this type of antenna until I get my yagis up in the summer. It works great with just 100 watts. I feed it thru a remote mounted automatic antenna tuner located outside the south end of the house with coax going to the shack on the north end of the house. The 1:1 balun is simply two parallel pieces of 12 gauge house wire wound on a plastic form about two inches in diameter and about a foot long. Output of tuner to one end and balanced feeders connect to the other end. You can do the same with a shack tuner but need to be careful routing the balanced feeders.
If you are looking for a decent multiband antenna about the cheapest and best antenna going is a simple doublet fed with ladder line and fed thru a tuner and balun. Note I said BALUN. It is not a BALUM. A doublet fed with 450 ohm ladder line and anywhere from 51-66 feet on each side and erected as an inverted VEE will be pretty much omnidirectional, will work from 80-6m and will have gain on the higher bands.. Half that size will work very well for 40m and up. I am presently using this type of antenna until I get my yagis up in the summer. It works great with just 100 watts. I feed it thru a remote mounted automatic antenna tuner located outside the south end of the house with coax going to the shack on the north end of the house. The 1:1 balun is simply two parallel pieces of 12 gauge house wire wound on a plastic form about two inches in diameter and about a foot long. Output of tuner to one end and balanced feeders connect to the other end. You can do the same with a shack tuner but need to be careful routing the balanced feeders.
Just throwing this out there, I use a shorty 80/40 meter dipole for hf. When I first bought the dipole, I had it mounted 5 feet off the ground on my back fence. Using 100 watts and a tuner, I worked a guy on 20 meters, who was in Bosnia Not bad Eh?and a quick Howdy to CK,^^ Hope you guys are getting some better weather
Not bad Eh?and a quick Howdy to CK,^^ Hope you guys are getting some better weather