-
You can now help support WorldwideDX when you shop on Amazon at no additional cost to you! Simply follow this Shop on Amazon link first and a portion of any purchase is sent to WorldwideDX to help with site costs.
Just put up I-Max 2000
- Thread starter Heavy Metal
- Start date
Use the coax you have, make connections using barrel connectors and make sure they are water tight.
Coax seal or some form of water sealant.
Good coax is good, but look at the loss of lmr 400 compared to say RG8 at 100' length at 30 mhz.
then ask yourself is it really worth spending the extra $$ for .2 or .5dbd less loss in your coax.
Coax seal or some form of water sealant.
Good coax is good, but look at the loss of lmr 400 compared to say RG8 at 100' length at 30 mhz.
then ask yourself is it really worth spending the extra $$ for .2 or .5dbd less loss in your coax.
I have to agree. Most operators get far too concerned with coax losses at 27 MHz. They think that 1 dB will equate to not being heard versus being copied with no problem I think. Also when comparing cable losses you must remember to look at the overall difference in losses and not just the total losses. Up to 30 MHz there is very little to be gained in changing coax cables. Things change at 50 MHz somewhat and a lot at VHF and up however.
RG8X has 2.0 dB loss @ 30MHz while 9913 has 0.8 dB loss per 100 feet. The difference of 1.2 dB will not be noticed on either end of the contact as it will be about 1/4 of an S-unit or about the width of a needle on the meter. If that is worth the extra cost then go for it otherwise put the money into a good station accessory like a decent meter or dummy load.
I got the IMax 2000 from a friend for free, added the ground plane package and used it just for 10 for a while, didn't change the rings nor shortened the Imax.
SWR with that set up was good on 12 and 15 as well, 18 left some hgher SWR on the meter, so when I was back on the roof I used PTFE covered silvered copper wire ( from Airbus production) and added 4 x 17 fet spread out on the roof slanted at 45 degree with some weights at the end to keep it in place.
That brought down the SWR on 18 to levels under 2:1 more then satisfactory and the MFJ 993-B can handle the rest or the Heathkit SB-1000 doesn't have a sweat over it.
The other bands all all under 2:1 in this way so I'm quite pleased how it works.
Just guessing that the main lobe came down a bit too with the longer ground plane wires, not set it out in Eznec because it is just one of 3 antenna's fit to work these bands.
In the 9 years it's up I worked all continents with it, 10/12/15/18 with 100 - 200 watts.
I also used the Heathkit on it on the bands running 600 - 900 watts in it, no smoke
Never tried 11 meters, that is quite dead here so I don't even listen there the last years.
Still have a Super star 3900 FM here multiband with counter used if for 10 for a while, now collecting dust.
And the old model Lincoln as well also gathering dust till I drag it back into the car with magnetic mount and antenna.
The Imax is up 40 feet over the ground on the roof of the house.
SWR with that set up was good on 12 and 15 as well, 18 left some hgher SWR on the meter, so when I was back on the roof I used PTFE covered silvered copper wire ( from Airbus production) and added 4 x 17 fet spread out on the roof slanted at 45 degree with some weights at the end to keep it in place.
That brought down the SWR on 18 to levels under 2:1 more then satisfactory and the MFJ 993-B can handle the rest or the Heathkit SB-1000 doesn't have a sweat over it.
The other bands all all under 2:1 in this way so I'm quite pleased how it works.
Just guessing that the main lobe came down a bit too with the longer ground plane wires, not set it out in Eznec because it is just one of 3 antenna's fit to work these bands.
In the 9 years it's up I worked all continents with it, 10/12/15/18 with 100 - 200 watts.
I also used the Heathkit on it on the bands running 600 - 900 watts in it, no smoke
Never tried 11 meters, that is quite dead here so I don't even listen there the last years.
Still have a Super star 3900 FM here multiband with counter used if for 10 for a while, now collecting dust.
And the old model Lincoln as well also gathering dust till I drag it back into the car with magnetic mount and antenna.
The Imax is up 40 feet over the ground on the roof of the house.
I got the IMax 2000 from a friend for free, added the ground plane package and used it just for 10 for a while, didn't change the rings nor shortened the Imax.
SWR with that set up was good on 12 and 15 as well, 18 left some hgher SWR on the meter, so when I was back on the roof I used PTFE covered silvered copper wire ( from Airbus production) and added 4 x 17 fet spread out on the roof slanted at 45 degree with some weights at the end to keep it in place.
That brought down the SWR on 18 to levels under 2:1 more then satisfactory and the MFJ 993-B can handle the rest or the Heathkit SB-1000 doesn't have a sweat over it.
The other bands all all under 2:1 in this way so I'm quite pleased how it works.
Just guessing that the main lobe came down a bit too with the longer ground plane wires, not set it out in Eznec because it is just one of 3 antenna's fit to work these bands.
In the 9 years it's up I worked all continents with it, 10/12/15/18 with 100 - 200 watts.
I also used the Heathkit on it on the bands running 600 - 900 watts in it, no smoke
Never tried 11 meters, that is quite dead here so I don't even listen there the last years.
Still have a Super star 3900 FM here multiband with counter used if for 10 for a while, now collecting dust.
And the old model Lincoln as well also gathering dust till I drag it back into the car with magnetic mount and antenna.
The Imax is up 40 feet over the ground on the roof of the house.
JustMe, a year or so back I did an Imax model with longer 1/2 wave radials and I also slanted them down.
Below is what I get using Eznec for an Imax, with no tuning device, but within reason for a bad match...I don't think a mismatch makes enough difference to worry about. However I will say these models are only general in nature as to what might happen, and would have to be tested in the real world...if we really wanted to know how this idea really works.
My Imax model is only 18' above the Earth, and I fixed these models to more like you suggest above. I made 3 models with horizontal radials equal 72", 108", and 204" or 17' feet like you suggest.
Then I slanted the radials down 70* degrees, and at 45* degrees in another 2 models to show what Eznec might predicts for your setup idea.
I also added the "source data" report (feed point match) so you might get an idea what is going on with the match you see in your setup with longer and slanted down radials.
If the base of your Imax is as I think you may be describing here...your antenna base is about net 22' feet above the ground, and the tip at near 40' feet. If I'm wrong my models are not setup exactly equal to what you have. Can you show me a picture with some added dimensions, and I'll try and get the models closer to your setup?
JustMe, there is a man in Houston, Tx, my location, that wrote an article in a popular radio Magazine years ago. Your idea is similar to his...and he made similar claims. I tried to talk to him back then, but he refused. I saw his Imax, but it was just a regular Imax with a regular looking GPK in his back yard...so I wondered about his report. He even went out to 5/8 wave with a single radial to prove a point.
So, I figured he just modeled the idea and did not test it in the real world. If I can find this work...I'll post it. However he was a draftsman and he posted his stuff on draft paper, and it is not very clear when copied.
Good luck...I'm sure some others might try this idea out...it does show some possibilities and maybe the angles this idea produces...are not really so bad for some DX conditions, but I'm not sure about very long range conditions.
Just me.
YOu added four 1/4 wl radials for 17 meters under your I2K and it brought the VSWR down under 2:1?
Are you using a choke or ugly balun at the feed point of the I2K?
I also use an I2K doe 10/12/15 meters but no ground plane and an RF choke at the feed point.
I have yagi's that cover those bands but the Imax is great for listening and then use the yagi to make the contact.
YOu added four 1/4 wl radials for 17 meters under your I2K and it brought the VSWR down under 2:1?
Are you using a choke or ugly balun at the feed point of the I2K?
I also use an I2K doe 10/12/15 meters but no ground plane and an RF choke at the feed point.
I have yagi's that cover those bands but the Imax is great for listening and then use the yagi to make the contact.
Thanks Marconi for the data, appreciated.
If you look me up on QRZ ( PA5COR) the you see my set up there, the roof of the house is 31 feet from the ground up, the small mast is just 7 feet, so in total the mounting hardware of the Imax 2000 is about 40 feet from the ground.
The 4 wires are slanted at about 45 degree down angle, a tad over 5 meters long, or 16 feet length.
Using a European low loss coax about the same specs of LMR 400, just 2 ferrite clamps on that coax just beneath the connector type 43 material., that is what was in the junkbox at the time.
About 30 feet from the Imax 2000 is the inverted L you see on the last picture on QRZ.com, in my bio, that one is 77 feet high, undoubtly it will have some interference and coupling with the Imax.
Ground here is excellent young salty seaclay, around the house there is 3000 feet of copper wire in/on the ground as radials for the inverted L, which is fed with the MFJ 998 legal limit tuner at the feeedpoint.
With that I can use the inverted L from 160 - 10, length of the inverted L is 77 feet high and another 77 feet sloping down to a mast in the trees you see behind in the last piccie at 45 feet above ground.
click on piccie in my bio for bigger size.
There is also an OCF antenna an original Fritzel FD-4, lengthened with coil and 33 feet of wire after the coil on the short side of the FD-4 to resonate it on 160 meters, so that one works as well from 160 -10 minus 2 warc bands.
That one has it's feeding point in the other mast with the 6/2/70 cm's beams and vertical for 2/70.
Having those antenna's as close as they are there will be some interaction.
The GPK kit from the IMAX didn't really change the SWR at 18meters, in my opinion it brought the main lobe a bit down on 10/12, I could not see changes in the swr then, looking at the notes I kept doing the changes.
The main change came from the added 4 wires of 5 meters length which influenced 18 meters and 15 meters and lowered their swr a bit, as long it is under 2:1 I don't mind, 10% loss can't be noticed on the other side anyway, the tuner or P.A. takes care of the rest.
So, for an total investment of 60 dollars for the GPK kit I have a working antenna that does fine for 18 - 10 meters, without coils, withstood force 12 gale storms with 115 mile gusts, and on all the bands using mostly 100 -200 watts I worked all continents with good reports.
Being able to switch from horizontal/vertical with the OCF and Imax I can pick the antenna that works the best at that given time, on all bands I can use the inverted L or the horizontal wire to change from Horizontal or vertical mode.
Where the NVIS antenna has a dead zone, the vertical will fill that one up
Add the homebrew receive loop with homebrew amplifier, and reception wise I have 3 antenna's for each band to pick from which gives the best reception at that time, for 160 a must.
I'm mostly on 160 meters, worked in phone from the Netherlands Brazil USA, Canada, USSR up to 5000 miles near the Chinese border with 800 watts into the inverted L, all confirmed as well.
Just to give an idea what you can do living on the edge of the city and limited space ( plot is just 100 x 21 feet wide).
Sorry for rambling on, just giving as clear picture of my setup as possible.
If you look me up on QRZ ( PA5COR) the you see my set up there, the roof of the house is 31 feet from the ground up, the small mast is just 7 feet, so in total the mounting hardware of the Imax 2000 is about 40 feet from the ground.
The 4 wires are slanted at about 45 degree down angle, a tad over 5 meters long, or 16 feet length.
Using a European low loss coax about the same specs of LMR 400, just 2 ferrite clamps on that coax just beneath the connector type 43 material., that is what was in the junkbox at the time.
About 30 feet from the Imax 2000 is the inverted L you see on the last picture on QRZ.com, in my bio, that one is 77 feet high, undoubtly it will have some interference and coupling with the Imax.
Ground here is excellent young salty seaclay, around the house there is 3000 feet of copper wire in/on the ground as radials for the inverted L, which is fed with the MFJ 998 legal limit tuner at the feeedpoint.
With that I can use the inverted L from 160 - 10, length of the inverted L is 77 feet high and another 77 feet sloping down to a mast in the trees you see behind in the last piccie at 45 feet above ground.
click on piccie in my bio for bigger size.
There is also an OCF antenna an original Fritzel FD-4, lengthened with coil and 33 feet of wire after the coil on the short side of the FD-4 to resonate it on 160 meters, so that one works as well from 160 -10 minus 2 warc bands.
That one has it's feeding point in the other mast with the 6/2/70 cm's beams and vertical for 2/70.
Having those antenna's as close as they are there will be some interaction.
The GPK kit from the IMAX didn't really change the SWR at 18meters, in my opinion it brought the main lobe a bit down on 10/12, I could not see changes in the swr then, looking at the notes I kept doing the changes.
The main change came from the added 4 wires of 5 meters length which influenced 18 meters and 15 meters and lowered their swr a bit, as long it is under 2:1 I don't mind, 10% loss can't be noticed on the other side anyway, the tuner or P.A. takes care of the rest.
So, for an total investment of 60 dollars for the GPK kit I have a working antenna that does fine for 18 - 10 meters, without coils, withstood force 12 gale storms with 115 mile gusts, and on all the bands using mostly 100 -200 watts I worked all continents with good reports.
Being able to switch from horizontal/vertical with the OCF and Imax I can pick the antenna that works the best at that given time, on all bands I can use the inverted L or the horizontal wire to change from Horizontal or vertical mode.
Where the NVIS antenna has a dead zone, the vertical will fill that one up
Add the homebrew receive loop with homebrew amplifier, and reception wise I have 3 antenna's for each band to pick from which gives the best reception at that time, for 160 a must.
I'm mostly on 160 meters, worked in phone from the Netherlands Brazil USA, Canada, USSR up to 5000 miles near the Chinese border with 800 watts into the inverted L, all confirmed as well.
Just to give an idea what you can do living on the edge of the city and limited space ( plot is just 100 x 21 feet wide).
Sorry for rambling on, just giving as clear picture of my setup as possible.
As you can read from my quite long answer to Marconi, the added wires are 17 to 18 feet long, 5+ meters long, just a bit longer as 1/4 wave at the lowest used frequency at 18 MHz.
The choke is 2 x type 43 material large clamp on ferrite's that were at the junkbox at the time, don't think they do a lo there.
What I did find was that the Imax was quite sensitive without any ground wires getting close to the antenna set off the swr quite easy and shifted the resonating point.
Adding the GPK kit from Imax changed that for the higher bands since most measurements were done at the antenna base with a short jumper and a MFJ 269 antenna analyser measuring directly at the antenna.
The added long wires also took care of 21 and 18 MHz bands, removing the sensitivity to near objects shifting the swr and resonating points.
I clamped on the ferrites just to be sure and they were in the junkbox anyway
Can't put up beams here, already the roof here looks like Jodrell bank with all the antenna's up here.
Living here for the last 28 years I made the best of what I have to work with, and it suits me well, I can run the amplifier here without getting my neighbours at the front door with pitchforks demanding ceasing transmitting
I never look for an easy way out, hence my 160 meter obsession, why take the easy road if there is a challenge?
When I started with 160 meters every ham here told me it would not work in the city, and yes there are challenges to overcome, but I did that.
Just another reason I work in Phone and not digital or CW.
Would be quite easy to work the world on 160 digital modes or CW, but where is the challenge?.
Must be the reason I use the Desert Eagle in .357 Magnum to do most of my target practice in our gunclub, and beat the sh*t out of the guy's with their nifty tuned and prepped 9 mm target pistols
After winning all trophy's with the S&W 629 classic DX .44 Magnum revolver I sold that one off, no challenges left there.
When they tell me it cannot be done I will do try to find a way to get it done.
The choke is 2 x type 43 material large clamp on ferrite's that were at the junkbox at the time, don't think they do a lo there.
What I did find was that the Imax was quite sensitive without any ground wires getting close to the antenna set off the swr quite easy and shifted the resonating point.
Adding the GPK kit from Imax changed that for the higher bands since most measurements were done at the antenna base with a short jumper and a MFJ 269 antenna analyser measuring directly at the antenna.
The added long wires also took care of 21 and 18 MHz bands, removing the sensitivity to near objects shifting the swr and resonating points.
I clamped on the ferrites just to be sure and they were in the junkbox anyway
Can't put up beams here, already the roof here looks like Jodrell bank with all the antenna's up here.
Living here for the last 28 years I made the best of what I have to work with, and it suits me well, I can run the amplifier here without getting my neighbours at the front door with pitchforks demanding ceasing transmitting
I never look for an easy way out, hence my 160 meter obsession, why take the easy road if there is a challenge?
When I started with 160 meters every ham here told me it would not work in the city, and yes there are challenges to overcome, but I did that.
Just another reason I work in Phone and not digital or CW.
Would be quite easy to work the world on 160 digital modes or CW, but where is the challenge?.
Must be the reason I use the Desert Eagle in .357 Magnum to do most of my target practice in our gunclub, and beat the sh*t out of the guy's with their nifty tuned and prepped 9 mm target pistols
After winning all trophy's with the S&W 629 classic DX .44 Magnum revolver I sold that one off, no challenges left there.
When they tell me it cannot be done I will do try to find a way to get it done.
JustMe, below is an image of my 1.50" square target on a 7" x 4" card at the top, and my Loading Log Record book from back in the early 70's...when I use to make loads for my pistols and long guns...on the bottom.
Pictured is my best load for a custom Bull Barrell .222 Remington Mohawk 600 with a 4-Plex Redfield at 100 yards. Again the real target is on the top and the log is on the bottom. That day of my testing a new load, I also let my 10 year old son, Harry, shoot his Winchester .22 long bolt action carbine at the same target with open sights no less. I trained each of my children in all of my hobbies over the years...even loading.
On the log I traced the actual 1/2" inch pattern in the lower right hand corner.
Pictured is my best load for a custom Bull Barrell .222 Remington Mohawk 600 with a 4-Plex Redfield at 100 yards. Again the real target is on the top and the log is on the bottom. That day of my testing a new load, I also let my 10 year old son, Harry, shoot his Winchester .22 long bolt action carbine at the same target with open sights no less. I trained each of my children in all of my hobbies over the years...even loading.
On the log I traced the actual 1/2" inch pattern in the lower right hand corner.
Last edited:
I have 4 guns left at the moment, sold off the beretta 92FS 9 mm stainless steel and the S&W 629 Classic DX to my brother in law because he really wanted them bad.
I have left the Desert Eagle in .357 M the S&W 686 in .357M the US M1 .30 Carbine from 1944 my father used in WW2 as member of the resistance, and the Walther .22 LR GSP target pistol.
Reloading the .357's and carbine with Vihtavuori N110 powder, CCI primers, and a choice of bullets from lead to JHP's here.
The carbine has been scoped with the Bushnell sportview 3x9 times magnification and 50 mm front lens, giving lots of light and contrast.
We have indoor lanes here 25 meters and 100 meter lane for any caliber up to and .50 BMG.
The revolver is almost new, the desert eagle is the old A type I bought new when it came out 20 odd years back before they were getting fame in movies, loved the weight and my big hands take care of the grip.
Our gun clubs have over 1000 members, I shoot in the highest class, after my back problems came up I ditched the heavy loads for the .44 M and went back to the .357M
The carbine isn't the most accurate rifle there is but with the scope you still can make nice groups at 100 meters, though a good bolt action rifle will beat it any day, but then it is my fathers old gun made in 05-1944, original barrel etc.
I use light loads in the carbine, not wanting to harm it in any way, using very hard letter lead bullets the carbine will not foul up either and I do have the tool to clean the ram that drives the bolt back.
Good shooting I saw, looks like we have the same interests
We have a fun lane where we do the pinball shooting, falling plate shooting
As well other action shooting.
50 miles away is an open shooting place with 300 and 500 meter ranges.
Maybe i'll opt for a bolt action rifle in the future for long range shooting, we'll see
Good shooting, stay safe now ...
Sorry, no targets with nice scores saved, just jotted down in my scorebook.
Multi stage press and single stage press here in use, bulk fun shooting using the multistage press target shooting through single stage press.
I have left the Desert Eagle in .357 M the S&W 686 in .357M the US M1 .30 Carbine from 1944 my father used in WW2 as member of the resistance, and the Walther .22 LR GSP target pistol.
Reloading the .357's and carbine with Vihtavuori N110 powder, CCI primers, and a choice of bullets from lead to JHP's here.
The carbine has been scoped with the Bushnell sportview 3x9 times magnification and 50 mm front lens, giving lots of light and contrast.
We have indoor lanes here 25 meters and 100 meter lane for any caliber up to and .50 BMG.
The revolver is almost new, the desert eagle is the old A type I bought new when it came out 20 odd years back before they were getting fame in movies, loved the weight and my big hands take care of the grip.
Our gun clubs have over 1000 members, I shoot in the highest class, after my back problems came up I ditched the heavy loads for the .44 M and went back to the .357M
The carbine isn't the most accurate rifle there is but with the scope you still can make nice groups at 100 meters, though a good bolt action rifle will beat it any day, but then it is my fathers old gun made in 05-1944, original barrel etc.
I use light loads in the carbine, not wanting to harm it in any way, using very hard letter lead bullets the carbine will not foul up either and I do have the tool to clean the ram that drives the bolt back.
Good shooting I saw, looks like we have the same interests
We have a fun lane where we do the pinball shooting, falling plate shooting
As well other action shooting.
50 miles away is an open shooting place with 300 and 500 meter ranges.
Maybe i'll opt for a bolt action rifle in the future for long range shooting, we'll see
Good shooting, stay safe now ...
Sorry, no targets with nice scores saved, just jotted down in my scorebook.
Multi stage press and single stage press here in use, bulk fun shooting using the multistage press target shooting through single stage press.
A change of subject in this thread, but thanks for the update Justme. Sorry HeavyMetal
I can't see much any more. My favorite long gun load over the .22lr, .270, and .3006, was the .222. I know you probably know why.
I primarily loaded for accuracy, pattern, and best load results.
My younger brother was a competition class on the Air Force team of his day. He used an accuraized M1 Grand .3006, and shot mostly a 1000 yards, but he may have also shot out to a mile, and I recall he won his fair share of contests. Guns kinka' run in our blood down here.
My best loading results with pistols in the order of best were an accurized Colt CC .45acp, off the shelf Ruger Super BH single action .44mag without a transfer bar safety, and an old S/W Texas Ranger .38 revolver my dad used in his days. I do not like the .357 loads, or the .45 revolvers I've owned, but I still have a Colt Python...it just has the feel of a fine weapon and it thinks it is a precision fire breathing cannon.
I'll also say all the 9mm's I ever owned were all-over and beyond the targets too.
Thanks for reminiscing with me.
I can't see much any more. My favorite long gun load over the .22lr, .270, and .3006, was the .222. I know you probably know why.
I primarily loaded for accuracy, pattern, and best load results.
My younger brother was a competition class on the Air Force team of his day. He used an accuraized M1 Grand .3006, and shot mostly a 1000 yards, but he may have also shot out to a mile, and I recall he won his fair share of contests. Guns kinka' run in our blood down here.
My best loading results with pistols in the order of best were an accurized Colt CC .45acp, off the shelf Ruger Super BH single action .44mag without a transfer bar safety, and an old S/W Texas Ranger .38 revolver my dad used in his days. I do not like the .357 loads, or the .45 revolvers I've owned, but I still have a Colt Python...it just has the feel of a fine weapon and it thinks it is a precision fire breathing cannon.
I'll also say all the 9mm's I ever owned were all-over and beyond the targets too.
Thanks for reminiscing with me.
Last edited:
A change of subject in this thread, but thanks for the update Justme. Sorry HeavyMetal
I can't see much any more. My favorite long gun load over the .22lr, .270, and .3006, was the .222. I know you probably know why.
I primarily loaded for accuracy, pattern, and best load results.
My younger brother was a competition class on the Air Force team of his day. He used an accuraized M1 Grand .3006, and shot mostly a 1000 yards, but he may have also shot out to a mile, and I recall he won his fair share of contests. Guns kinka' run in our blood down here.
My best loading results with pistols in the order of best were an accurized Colt CC .45acp, off the shelf Ruger Super BH single action .44mag without a transfer bar safety, and an old S/W Texas Ranger .38 revolver my dad used in his days. I do not like the .357 loads, or the .45 revolvers I've owned, but I still have a Colt Python...it just has the feel of a fine weapon and it thinks it is a precision fire breathing cannon.
I'll also say all the 9mm's I ever owned were all-over and beyond the targets too.
Thanks for reminiscing with me.
Nah 22-250 30-06 270 7mm mag 300 win mag 270 243 308 assault 223/nato assault
45 44 460 500 357 9mm
Mathews q2xl 6.5 reezen and xlr8 (#80 draw )
And plenty of room to shoot hunt in back yard wonderful to just go hunt or just target...
Wonder if put it over a tin roof how high or how low above it should one go to make it act as a ground plane.