So I got 1.2 SWR from 26.6550 to 27.1050. So wonder how much to lower the top sections to get the 1.2 across the 11 meter band? Any guesses?
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New Sirio Tornado 27
- Thread starter Galaxy 959
- Start date
Keep going down until VSWR starts to rise on low end of CB band. Right now your antenna is still too long. What is the reading at 27.405 or channel 40?? This is where you need to be looking. As long as the VSWR keeps going down on the upper channels and channel 1 remains the same VSWR or gets a bit lower. You are still too long IMO. It's trial and error with only having an swr meter. Did you set the top whip to 1030mm or 40.55" or less? If not then keep going down. You are on the right track I believe and just need to stick with it. Like I said, MARK the whip at the point you have it at and measure this and note it. Then drop the whip down a good bit, about 1" from where it is now. Check VSWR starting on channel 20, or 27.205, see what VSWR is here, then move to channel 1, and take reading, then move to channel 40 and take reading. Make notes of all the readings. Now, if the VSWR on channel 40 is still higher then channel 1, your antenna is still too , of channel 40 reading is lower than channel 1 and 20, than that antenna is too short. Given the original readings you gave were 1.2:1 CH1, and 1.3:1 CH40, and what you are reading now, 1.2:1 across 26.655-27.105, you are still too long at the tip. Like I said, try moving the whip a good bit more than you have been, like 1", but before you do anything, MARK THE WHIP.
Again, IMO you're on the right track and probably very close to where yoi need to be. Don't be afraid to make a large change in the whip length. Every antenna install is different and what might work for Joe might not work for Bob. Also, at least add 1 if not more 8FT x 5/8" copper ground rods. They aren't expensive!! 2 for less then $25 at Home Depot. Place the ground rod about 2-3ft from antenna mast and drive it all the way down until only about 4" remains. Then ground your mast. This might not do a damn thing for the VSWR, but it should be done regardless IMO. And also ground all your equipment as well. JMHO. But like I said, I think you are on the right track as far as tuning of antenna goes, but your top whip is still too long IMHO. Don't get frustrated and like I said, mark all changes to the whip and note them as well. Length, VSWR readings, and so on. It will help in the end as you won't be playing guess the length so much. Promise!! Been there and some that!! And I know it sucks. But if you want to get it right for the freqs you talk on the most, tune it for those specific freqs. You need to have a set freq at any rate and establish a base line reading at that set freq and go from there. For the center of the CB band, 27.205 is going to be what you want as your set freq.
Start here and note the VSWR reading currently here as well as the other freqs (ch1 & ch40.). Then start to lower the whip and do what I posted above. Not trying to tell you how to do things man, just want to help. I have been exactly where you are and I promise I know how frustrating it can be!! Don't give up! But you need to note everything you do, as in the end it will help you understand what you are doing as well as get it right the first go round of tuning. Hope it all helps and hope you get it where you want it to be.
Again, IMO you're on the right track and probably very close to where yoi need to be. Don't be afraid to make a large change in the whip length. Every antenna install is different and what might work for Joe might not work for Bob. Also, at least add 1 if not more 8FT x 5/8" copper ground rods. They aren't expensive!! 2 for less then $25 at Home Depot. Place the ground rod about 2-3ft from antenna mast and drive it all the way down until only about 4" remains. Then ground your mast. This might not do a damn thing for the VSWR, but it should be done regardless IMO. And also ground all your equipment as well. JMHO. But like I said, I think you are on the right track as far as tuning of antenna goes, but your top whip is still too long IMHO. Don't get frustrated and like I said, mark all changes to the whip and note them as well. Length, VSWR readings, and so on. It will help in the end as you won't be playing guess the length so much. Promise!! Been there and some that!! And I know it sucks. But if you want to get it right for the freqs you talk on the most, tune it for those specific freqs. You need to have a set freq at any rate and establish a base line reading at that set freq and go from there. For the center of the CB band, 27.205 is going to be what you want as your set freq.
Start here and note the VSWR reading currently here as well as the other freqs (ch1 & ch40.). Then start to lower the whip and do what I posted above. Not trying to tell you how to do things man, just want to help. I have been exactly where you are and I promise I know how frustrating it can be!! Don't give up! But you need to note everything you do, as in the end it will help you understand what you are doing as well as get it right the first go round of tuning. Hope it all helps and hope you get it where you want it to be.
Oh Ill get it 222. When I got someone here to help clamp it to the pole it will be easy. I can take it down and lower the top section easy but trying to hold it up to the pole and put the clamp on with the other hand is hard to do by myself. That thing swaying around in the air and trying to hold it with 1 hand just don't work to well. I got it the first time but going to get help when I adjust it.Keep going down until VSWR starts to rise on low end of CB band. Right now your antenna is still too long. What is the reading at 27.405 or channel 40?? This is where you need to be looking. As long as the VSWR keeps going down on the upper channels and channel 1 remains the same VSWR or gets a bit lower. You are still too long IMO. It's trial and error with only having an swr meter. Did you set the top whip to 1030mm or 40.55" or less? If not then keep going down. You are on the right track I believe and just need to stick with it. Like I said, MARK the whip at the point you have it at and measure this and note it. Then drop the whip down a good bit, about 1" from where it is now. Check VSWR starting on channel 20, or 27.205, see what VSWR is here, then move to channel 1, and take reading, then move to channel 40 and take reading. Make notes of all the readings. Now, if the VSWR on channel 40 is still higher then channel 1, your antenna is still too , of channel 40 reading is lower than channel 1 and 20, than that antenna is too short. Given the original readings you gave were 1.2:1 CH1, and 1.3:1 CH40, and what you are reading now, 1.2:1 across 26.655-27.105, you are still too long at the tip. Like I said, try moving the whip a good bit more than you have been, like 1", but before you do anything, MARK THE WHIP.
Again, IMO you're on the right track and probably very close to where yoi need to be. Don't be afraid to make a large change in the whip length. Every antenna install is different and what might work for Joe might not work for Bob. Also, at least add 1 if not more 8FT x 5/8" copper ground rods. They aren't expensive!! 2 for less then $25 at Home Depot. Place the ground rod about 2-3ft from antenna mast and drive it all the way down until only about 4" remains. Then ground your mast. This might not do a damn thing for the VSWR, but it should be done regardless IMO. And also ground all your equipment as well. JMHO. But like I said, I think you are on the right track as far as tuning of antenna goes, but your top whip is still too long IMHO. Don't get frustrated and like I said, mark all changes to the whip and note them as well. Length, VSWR readings, and so on. It will help in the end as you won't be playing guess the length so much. Promise!! Been there and some that!! And I know it sucks. But if you want to get it right for the freqs you talk on the most, tune it for those specific freqs. You need to have a set freq at any rate and establish a base line reading at that set freq and go from there. For the center of the CB band, 27.205 is going to be what you want as your set freq.
Start here and note the VSWR reading currently here as well as the other freqs (ch1 & ch40.). Then start to lower the whip and do what I posted above. Not trying to tell you how to do things man, just want to help. I have been exactly where you are and I promise I know how frustrating it can be!! Don't give up! But you need to note everything you do, as in the end it will help you understand what you are doing as well as get it right the first go round of tuning. Hope it all helps and hope you get it where you want it to be.
Get help. This is exactly how my antenna got destroyed!! Almost same way. Trying to bolt it back onto mast pipe!! Not worth it!! Having as many hands on deck as possible is a good thing. Even if they don't know crap about radios or antennas. All you need is holders!! At any rate. Be safe and i am sure you'll get it corrected!!
Yes, exactly 3", LoL.
Actually, I subtracted the correct calculated length for a 5/8 on 27.185 from the average of your 2 frequencies where you're getting your lowest swr and ended up with 3" difference, which might actually be close.
That's how I'd do it.
So the top whip is approx. 3" too long NB?? I know it's still too long IMO. The top whip is anyway. 3" is 76.2mm. That is a large jump im length of the top whip!! Anyways, I'd start with dropping it about 1" and go from there. It may well be 3", that is why I said to mark all settings with a good sharpie. The 5 pack or whatever it is, that has the different colors might be a good idea, as you can note the lengths per color and easily remember them this way. Not to say a plain old black one won't work just fine. Just write down everything you do before you start and then after as well. A good dude told me that and it has stuck ever since!! And it will save you arse a lot time in the end!!! Hope you get it right soon. The DX has been great at night. From about 8:00pm until midnight I was talking to people all the way up tub coast as well as out west to TN and north. Good stuff!!! At any rate, be safe and tske your time. You are close, keep at it!!
Yes. About 40"- 40.5" is is about where I think you need to place the top whip. With the analzyer you should be able to get it near perfect. Get yourself an n-male to pl259 connector to use at the feedpoint of the antenna for tuning or you will need to cut a 1/2 wave tuned coax jumper to use with the mfj259. For center freq of 27.205, you would need a coax jumper made of rg8x that is 14.82ft long. This is made for freq of 27.205 or channel 20. To get the correct length coax jumper you will need to use, you first need to establish a set freq for tuning and stick with it. Then cut a piece of coax using this formula for making a 1/2 wave tuned coax jumper. 492 x VF of coax, divided by frequency. So for 27.205 we use 492 x .82 / 27.205 which = 14.82ft.
You can use this method or use a connector directly from the MFJ259 meter to the antenna feed point. All that will be needed then is the adapter for the top of the mfj259 which most likely will have one with it. If not, RS carries N-Male to SO239 and a pl259 to pl259 barrel connector as we'll. Looks like these. Hope this helps and you will love having the mfj259!! It makes tuning of antennas much easier and actually you get a proper tune as well.
You want to get the antenna to show
R=50
X=0
VSWR: 1.0:1 or as close to this as possible while keeping the R and X values at the numbers above. Read the manual for the mfj259 before you use it!!! And you will be good to go. Enjoy your new toy!! And now there is no reason that you can't get the antenna right other then not having help to get it up/down!! Be safe and get er done!!
You can use this method or use a connector directly from the MFJ259 meter to the antenna feed point. All that will be needed then is the adapter for the top of the mfj259 which most likely will have one with it. If not, RS carries N-Male to SO239 and a pl259 to pl259 barrel connector as we'll. Looks like these. Hope this helps and you will love having the mfj259!! It makes tuning of antennas much easier and actually you get a proper tune as well.
You want to get the antenna to show
R=50
X=0
VSWR: 1.0:1 or as close to this as possible while keeping the R and X values at the numbers above. Read the manual for the mfj259 before you use it!!! And you will be good to go. Enjoy your new toy!! And now there is no reason that you can't get the antenna right other then not having help to get it up/down!! Be safe and get er done!!
Attachments
...or R=52Ω is also acceptable as some antennas are at 52 ohms when correctly tuned for X=0 & 1.0:1 SWR.
Ok I've had some time to mess with this today. I don't have my analyzer yet but I'm going in right direction. I still don't see why antenna has to be this short in my application to get the SWR closer to where it needs to be.
Top section measurements. Was at 41.5" when I started.
Went to:
39"
Ch1 1.2 and Ch 40 1.3 Radio Meter
Ch1 1.6 and Ch 40 2.8 Workman HP 201S
Went to:
37"
Ch 1 1.2 and Ch 40 1.3 Radio Meter
Ch 1 1.4 and Ch 40 2.5 Workman HP 201S
Should I just keep going lower even though its out of the Chart range from Sirio?
Top section measurements. Was at 41.5" when I started.
Went to:
39"
Ch1 1.2 and Ch 40 1.3 Radio Meter
Ch1 1.6 and Ch 40 2.8 Workman HP 201S
Went to:
37"
Ch 1 1.2 and Ch 40 1.3 Radio Meter
Ch 1 1.4 and Ch 40 2.5 Workman HP 201S
Should I just keep going lower even though its out of the Chart range from Sirio?
Keep in mind I had this same problem with my Antron. Most of the time you can just put them up and the SWR is good. I had to put the rings all the way to the top nearly to get the SWR 1 across the band. I don't know if its my location or what.
Ok I went ahead and put it at 34" just to see what happens.
Ch 1 1.4 and Ch 40 1.2 Radio
Ch 1 1.2 and Ch 40 1.9 Workman HP201S
So what do you think?
Ch 1 1.4 and Ch 40 1.2 Radio
Ch 1 1.2 and Ch 40 1.9 Workman HP201S
So what do you think?
Ok this is my final measurement for now. Its setting at 35"
Ch 1 1.1 Ch 40 1.8 Workman Meter
Ch 1 1.2 Ch 40 1.2 Radio Meter
I have 2 different radios also and they both read the same. So I think the workman may be off a little bit.
Ch 1 1.1 Ch 40 1.8 Workman Meter
Ch 1 1.2 Ch 40 1.2 Radio Meter
I have 2 different radios also and they both read the same. So I think the workman may be off a little bit.
Ok this is kinda weird. I done all this checking by just sitting the antenna over the end of the pole because it will fit in it. That makes it easy for me doing it myself. When I used the clamps to fasten it back to the side of the pole and raised it back up just over 2' to take the slack out of the coax it lowered the SWR some more. The antenna is setting at 20' to the bottom. Was testing at around 18'.
Ch 1 1.1 and Ch 40 1.4 Workman meter.
Ch 1 1.1 and Ch 40 1.1 Radio meters.
I still don't understand why it has to be so short below chart scale to reach the lower SWR.
Ch 1 1.1 and Ch 40 1.4 Workman meter.
Ch 1 1.1 and Ch 40 1.1 Radio meters.
I still don't understand why it has to be so short below chart scale to reach the lower SWR.