I was only suggesting that as part of troubleshooting, not for regular operations. It would tell you if there is some interaction with other parts of the crane.
I am laughing at the original thought though.
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Imax 2000 on a 190' tower crane Swr problem
- Thread starter DC Star (3831)
- Start date
I am laughing at the original thought though.
[QUOTE="Road Squawker, post: 546910, member: 17089"using your analyzer, what is the SWR & OHM's when X = 0?[/QUOTE]
Swr 3.3
Ohm 15
Swr 3.3
Ohm 15
looking at the i2k and having installed a few of my own.
1st the tuning rings need to be put back center of the adjustments, or as close to factory as you can, this fishing pole is good from the factory no need for adjustment,
2nd is I do not see a very good ground, the pole is not really long enough but the main concern is if the mast pole/pipe is actually bonded to the structure. Just sitting in a bigger pipe will not give a good enough ground to act as the other half of the end fed antenna.
You can try a quick fix, get around 8'6" to 9' of wire, any old wire and attach it to the mounting base of the i2k so it will act as a counterpoise, if that fixes the problem then you need to actually bond the mast pipe to the crane structure, drill holes good bond to ground and good luck, man 190, can I put an 160 meter inverted v antenna up there also???
Hell an 75 meter wire would SCREAM that high above ground
and wrap an ugly balun rf choke at the feed point of that end feed fishing pole to prevent CMC, you mentioned line isolator they work also.
1st the tuning rings need to be put back center of the adjustments, or as close to factory as you can, this fishing pole is good from the factory no need for adjustment,
2nd is I do not see a very good ground, the pole is not really long enough but the main concern is if the mast pole/pipe is actually bonded to the structure. Just sitting in a bigger pipe will not give a good enough ground to act as the other half of the end fed antenna.
You can try a quick fix, get around 8'6" to 9' of wire, any old wire and attach it to the mounting base of the i2k so it will act as a counterpoise, if that fixes the problem then you need to actually bond the mast pipe to the crane structure, drill holes good bond to ground and good luck, man 190, can I put an 160 meter inverted v antenna up there also???
Hell an 75 meter wire would SCREAM that high above groundand wrap an ugly balun rf choke at the feed point of that end feed fishing pole to prevent CMC, you mentioned line isolator they work also.
I see an issue that has been discussed before regarding the installation of the Imax. This was regarding the mast protruding above the mast mounting plate on the Imax.
It was noted that getting the mast pipe to close to the tuning rings area could cause some tuning problems. So, the solution was to make sure the top of the mast does not extend above the mounting plate and was flush.
The manual also discusses getting the Imax too close to metal from at least 9' feet below, and I see a lot of heavy metal within a couple of feet in the images.
You may have to go a bit higher and then check and see it the match gets better.
Just a note. I can't be sure at the angle of the image, but the rings look to be set too low if you are trying to tune for the middle of CB.
It was noted that getting the mast pipe to close to the tuning rings area could cause some tuning problems. So, the solution was to make sure the top of the mast does not extend above the mounting plate and was flush.
The manual also discusses getting the Imax too close to metal from at least 9' feet below, and I see a lot of heavy metal within a couple of feet in the images.
You may have to go a bit higher and then check and see it the match gets better.
Just a note. I can't be sure at the angle of the image, but the rings look to be set too low if you are trying to tune for the middle of CB.
Man you could have some fun with that setup! Ok ant looks to be in the clear.Try the wire waverider suggested.If still no good borrow a multimeter and check continuity of the plugs and coax.
I get terrible motion sickness in those cranes.Once had to fit a uhf yagi pointed at the ground, while crane was in use, spent the next 5 mins with my head in the bucket in the corner.
I get terrible motion sickness in those cranes.Once had to fit a uhf yagi pointed at the ground, while crane was in use, spent the next 5 mins with my head in the bucket in the corner.
looking at the i2k and having installed a few of my own.
1st the tuning rings need to be put back center of the adjustments, or as close to factory as you can, this fishing pole is good from the factory no need for adjustment,
2nd is I do not see a very good ground, the pole is not really long enough but the main concern is if the mast pole/pipe is actually bonded to the structure. Just sitting in a bigger pipe will not give a good enough ground to act as the other half of the end fed antenna.
You can try a quick fix, get around 8'6" to 9' of wire, any old wire and attach it to the mounting base of the i2k so it will act as a counterpoise, if that fixes the problem then you need to actually bond the mast pipe to the crane structure, drill holes good bond to ground and good luck, man 190, can I put an 160 meter inverted v antenna up there also???
and wrap an ugly balun rf choke at the feed point of that end feed fishing pole to prevent CMC, you mentioned line isolator they work also.
When I just had installed my Imax it was right next to a old copper j pole on another push up mast. So I took down the j pole and the swr is now close to prefect. I would say all the metal from the crane is the problem. Try mounting the Imax a good 20ft min away from the crane check swr again. Another thing is I would never run a Imax 200ft that is just to high if you get strong winds that antenna will snap in 2 much easier than at 50ft to 60ft. Would be cool to run a Imax mounted at 200ft stock radio you should get 25 to 30 miles no problem. DXing 250w everyone will think your running 750 w to 1k w.
So....Your saying he should mount the antenna 20' away from the crane it's currently mounted on? So your saying mounting it on a 200' metal tower 20' away from the crane would be better? Or should the 200' tower be made of wood or plastic so it doesn't interfere with the antenna?
You also say being so high, strong winds could snap the antenna, so it should be lower? I guess what your saying here is there's never strong winds at lower altitudes...Just wondering how strong do you think the wind is at 200'? Hurricane strength?
Looks like you have a metal extension pipe sitting in another yellow rusty metal pipe. You might need to drive a tek screw thru the old rusty yellow pipe into the extension pipe to get a good ground and make sure you have real bare metal to bare metal contact from the rusty yellow pipe to the crane frame. Not just hose clamps around a painted surface.
Also, does the new crane have wireless load meters? If so maybe an RFI issue when the computers and transceivers are operational?
I can see for miles and miles
Also, does the new crane have wireless load meters? If so maybe an RFI issue when the computers and transceivers are operational?
I can see for miles and miles
Also consider using some ferrite chokes around the coax at the feedpoint as well as the other things suggested. An RF isolator will help as well installed at the antenna feedpoint. Use a PL259 barrel connector. Or a very short coax jumper. Hope you get the issue resolved.
Enviable height and should really perform up there.
In my own experience mounting an IMAX2000 on a large iron/steel farmers gate (G-clamping the IMAX plate direct to the gate) I could never seem to get the SWR lower than 2:1 either, I have tried all sorts of choke types ferite and coaxial to no avail. I suspect if that was on an 18 feet pole the SWR would drop down no problems. All antennas I have used seem to like to be in as close as open space as possible, other than a mounting pole. You would think that a crane would be an awesome ground plane/counterpoise but sometimes a lot of metal under an antenna with no decent length of pole can cause high SWR in my own experiences.
(I suspect it can also affect the take of angle of some antennas, dipole types react especially badly including the Gain Master.. SWR is ok on the GM but you get high TOA's for DX and thus few contacts)
It seems to be very much exact setup specific, you can get lucky and get a good SWR and performance or a bad SWR and not so good performance. ( I know a guy who puts it on his ladders on the top of a van and it works fine for him) Other than this it seems impossible to predict what is and is not going to work when it comes to attaching an IMAX to a large metal structure. Results vary wildly and myself I only get an IMAX working when it is on 15 feet of pole and only with no chokes of any kind. That is where I get a SWR of 1.4:1 which is ok.
Of course an 18 feet pole and an IMAX on top, on top of a crane could become quite a safety issue for man handling so be careful.
I suspect that metal close the the lower portion of an IMAX does not work well. I also suspect you may find the antenna becomes slightly directional in the direction where most metal from the cranes horizontal elements exist. All guess work from my experiences here in the UK but hope you get the SWR down and have some fun contacts.
In my own experience mounting an IMAX2000 on a large iron/steel farmers gate (G-clamping the IMAX plate direct to the gate) I could never seem to get the SWR lower than 2:1 either, I have tried all sorts of choke types ferite and coaxial to no avail. I suspect if that was on an 18 feet pole the SWR would drop down no problems. All antennas I have used seem to like to be in as close as open space as possible, other than a mounting pole. You would think that a crane would be an awesome ground plane/counterpoise but sometimes a lot of metal under an antenna with no decent length of pole can cause high SWR in my own experiences.
(I suspect it can also affect the take of angle of some antennas, dipole types react especially badly including the Gain Master.. SWR is ok on the GM but you get high TOA's for DX and thus few contacts)
It seems to be very much exact setup specific, you can get lucky and get a good SWR and performance or a bad SWR and not so good performance. ( I know a guy who puts it on his ladders on the top of a van and it works fine for him) Other than this it seems impossible to predict what is and is not going to work when it comes to attaching an IMAX to a large metal structure. Results vary wildly and myself I only get an IMAX working when it is on 15 feet of pole and only with no chokes of any kind. That is where I get a SWR of 1.4:1 which is ok.
Of course an 18 feet pole and an IMAX on top, on top of a crane could become quite a safety issue for man handling so be careful.
I suspect that metal close the the lower portion of an IMAX does not work well. I also suspect you may find the antenna becomes slightly directional in the direction where most metal from the cranes horizontal elements exist. All guess work from my experiences here in the UK but hope you get the SWR down and have some fun contacts.
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