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Patzerozero
Senior Member
Username: Patzerozero
Post Number: 3814
Registered: 7-2004
| | Posted on Sunday, June 24, 2007 - 8:03 pm: | 
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do YOU use one of these BEAM/YAGI antennas? 3 or 4 element? i'd like to know the TRUE <2:1 SWR bandwidth of EACH of these antennas. NOT what the manufacturer states! please give me SPECIFIC high & low freqs your antenna measures 2:1 SWR at. |
Marconi
Advanced Member
Username: Marconi
Post Number: 735
Registered: 11-2001
| | Posted on Sunday, June 24, 2007 - 10:47 pm: |
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My beam is made from parts to an old Wilson 4 element Y-Quad. I use a stock Moonraker boom and spacing was set according to the boom dictates and my hardware. It is a bit narrow banded, but works very well for its age and design problems.
26.500 R=66 X=-47 @ 1.99
27.340 R=49 X=+4 @ 1.11
27.790 R=79 X=+34 @ 1.79 |
Starface
Senior Member
Username: Starface
Post Number: 1326
Registered: 1-2005
| | Posted on Monday, June 25, 2007 - 12:07 am: |
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Pat I answered you back on this question in your email to me.
Hope I was some help.
STARFACE
CEF#476
KI4NBE
HAM#181
CVC#Ø14
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Wildrat
Senior Member
Username: Wildrat
Post Number: 1307
Registered: 12-2003
| | Posted on Monday, June 25, 2007 - 9:31 am: |
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mine is still lying on the ground.
WILDRAT
Mark
27.285MHZ
CEF674
CVC029
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Patzerozero
Senior Member
Username: Patzerozero
Post Number: 3817
Registered: 7-2004
| | Posted on Monday, June 25, 2007 - 2:01 pm: |
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well, get 'em up there, 'rat, so you can take some measurements for me!
YES SIR george! THANKS! & i sent a reply back to you.
hey, Lon, i have a few questions about your  beams....who assembled/installed it? did you/they notice how well construction pieces/tube-wall thickness compare to sirio & maco? how about YOUR swr readings on 27.115 & 28.360?
marconi...saw your references elsewhere-i have cousins, aunt & uncle in magnolia. been a while, but, have been pontoon-boating on lake conroe, through tomball, etc....anyway, thanks for your readings-exactly HOW i wanted to see readings, but, alas, not QUITE the #'s i was hoping for-BUT we seem to be getting into the ballpark.
i am looking for a bit more broadbandedness, hopefully not at the expense of performance. while many commercially made 10 meter yagis show relatively little 2:1 bandwidth in print, on the order of 2:1 SWR over 500khz, CB yagis claim as much as 1500 khz, or more, for 2:1. makes me wonder if the commercial 10 meter yagis are accurately represented, bandwidth-wise. i have asked a couple copper members, & yours seems to be in line with what they say. i am awaiting your type of explanation from a few other 10/11 meter ops,who can get me readings on 27.115 & 28.360.
yeah, you know where i'm going with this. my maco v5/8 is still tuned at 1.1:1 on 27.025, & <1.9:1 on 28.360. i have checked R & X through 70' of 9913, & was fairly happy with what i got there, reflect readings on a diamond sx100 seem to be satisfactory as well, 40 watts carrier doesn't move the reflect needle on 27.025, 40 watts carrier shows just about 5 watts reflect on 28.360, so, i'm sure if i shortened it a hair, i can get both to within 2% reflect. i am hoping i can do the same with a 3 element beam, whether it be on the standard 11.5' boom, or a longer one.
i know, as long as the SWR is under 2:1....but i want the most efficiency possible from the start of this project, as i need room to play.
because, it doesn't end there. once i am sure i have the bandwidth to play with, i am going to.... |
Marconi
Advanced Member
Username: Marconi
Post Number: 736
Registered: 11-2001
| | Posted on Tuesday, June 26, 2007 - 10:35 am: |
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Pat, I guess you are hoping for more bandwidth than the 1200+ kHz noted. For me this will likely require an "always increased compromized adjustment" to the antenna spacing I believe. You will likely find this by making Dr to D1 farther appart. It might be better if you could make the boom longer, and I'm not sure of the real conquences to rejection and pattern if you don't.
Personally, I would go for the best setting possible in the band you desire the most and then use your tuner to work the other band. Broadbanding the antenna is bound to come at the expense of reduced gain and for sure a broader beamwidth directive pattern.
I think if you tuned as instructed for either 10 or 11 meters and then use the tuner with the other band you would probably be ahead of the game.
As an idea you might try downloading Yagi for Windows and play with a 10 meter three element for spacing and this might give you a good handle on the conquencies of trying to compromize without a lot of actual trial and error. It may not be a very accurate design tool, but it may give you some sense of change, cause and affect if you go slow in the attempt.
You are going to find that efficiency in an antenna is not something that you can really tell simply by operating and checking SWR. If you have an analyzer it can make the job easier if you don't watch the SWR to the excess in bringing the match to a 50 ohms center frequency where you want it. The problem then is getting the real resonance of the antenna at that same frequency without ill affecting the match to much.
I find this shortcoming quite often using different commercial 11 meter tunable antennas that I have. If I can't see an X value = 0 anywhere I scan around center frequency, then I suspect the match point and resonance are not at the same frequency regardless of what the SWR is. I believe when this happens, it is usually due the transforming affects of a random length feed line on an unmatched feed point. It is also impossible to very difficult to see such using an SWR meter. This can also happen with an analyzer if you totally rely on the SWR as an indicator of the accuracy in tuning, and for sure when using a long feed line to tune to an unmatched feeder. |
Patzerozero
Senior Member
Username: Patzerozero
Post Number: 3827
Registered: 7-2004
| | Posted on Thursday, June 28, 2007 - 6:22 pm: |
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increased spacing between director & driven element was almost a given. i have room for a v5/8 & it's 18' of radial spread, so, 3 elements on 16' of boom is OK-if absolutely needed. i've played around with 2 programs, & MOL-6 db forward gain, on both 27.2 & 28.4, with a peak of another 1.5 db in the middle seems a possibility, yes, at the expense of some rejection. R apparently is in the 40-60 range, X is gonna be the sticking point. spacing back or front of the driven element is going to have to be meticulously set, because of my previouly mentioned 'more'. the addition on a 6 meter yagi interlaced with the 10/11 meter yagi. applying commercially made full-sized dual/tri band yagi measurements into something from EZNEC, showed that if i substitued 50 mHz dimensions in place of 21 or 14 mhz dimensions, i could get near 6db from the 6 meter yagi, with the same compromise in rejection. again, from what i see of commercial made yagis, the lack of harmonic relationship between 27.8 & 50.15 mhz should help them see through each other.
i am just trying to see if different 11m beams using different wall thicknesses, or diameters, have any noticeably wider bandwidths then others. again, my v5/8 seems wider then maco specifies, so....there's no reason not to hope! i have 949e tuner, but i'd prefer to tweak a 1.5:1 swr, rather then a 3:1. a 1.5:1 TUNED ANTENNA performs better then a 3:1 TUNED ANTENNA, the matcher just allows full power to get to a MISTUNED antenna, so, efficiency drops. will that loss of efficiency be more or less then MY 3 band design......
i don't have all that much room to work with, that's the problem. i am willing to give up some performance to be able to get these 3 bands on 1 boom. i think it can be done, & keep reasonable gain, & only lose a bit of rejection. |
Marconi
Advanced Member
Username: Marconi
Post Number: 737
Registered: 11-2001
| | Posted on Friday, June 29, 2007 - 5:31 am: |
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Well Pat you are planning a very ambitious project and the complications are well above my experience and understanding. You seem to be anticipating properly, but I think even the best of the modeling software will show you some serious limitations unless you are well schooled in the applications.
I know an operator that put up a multi-band close to the range you are considering. It was very simple looking with one feed line only that was direct fed using only one coax. At the time this seemed to me to be an impossible task, but it worked out very nicely for him. He mounted it at about 30-40 feet and it was very effective. I don't recall if he had to use a tuner or not.
Good luck and keep us posted, |
Tech808
Moderator
Username: Tech808
Post Number: 13968
Registered: 8-2002
| | Posted on Friday, June 29, 2007 - 10:21 am: |
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Pat,
Sorry I missed your question below as I have been SWAMPED here lately with work and SKIP ie: talking with YOU and other CEF member's on 27.115 and 28.360. 
QUESTION:
(hey, Lon, i have a few questions about your beams....who assembled/installed it? did you/they notice how well construction pieces/tube-wall thickness compare to sirio & maco? how about YOUR swr readings on 27.115 & 28.360?)
ANSWER:
I assembled them in LESS than 30 minutes by myself.
Brian/Redman CEF#156 and Mike/Homeboy CEF#159 came over and removed/replaced and re-located my MACO M-103HV antenna and lowered it to the ground and replaced it with the new beams in less than 15 minutes at 54' since NO ADJUSTMENTS were needed "ON THE GROUND" or "IN THE AIR". 
NOTE!
They also removed, replaced, re-located and installed, 4 other antennas for side by side ACTUAL on air testing results/reports from other CEF Radio Club Member's.
In my OWN personal experience and opinion the construction and quality of the pieces ie: tube-wall thickness of elements, mounting hardware, main SQUARE boom and overall antenna quality is 100% superior to the Maco M103 HV antenna or any maco antenna or beam antennas that I have ever used over the years including the M103/M104/M103-HV and many other's.
There is NO guess work involved or adjustments needed or sliding of the elements in and out for a specific length or adjusting them on the main boom for spacing of the elements for a certain length on the main boom like with the maco beams as there are PRE-SET holes for the mounting of the element brackets on the boom thus {NO MISTAKES).
The quality of the part's/components/elements, boom and overall construction and performance and ease of assembly is 100% superior than any beams I have used in the last 30 years including, Joe Gunn, Maco, Gizmotchy, and Signal engineering beams.
NO 2-piece gamma matches that need adjustments like with the MACO gamma matches. Just 1 single solid aluminum piece that fits around the match rod and beam element and you measure 27" from the SO-239 connector and tighten it down and that's it (NO further adjustments needed).
The elements fit on top of the square tube main beam w/ 1 single bolt thru the support bracket that’s fits on top of each of the cross elements.
SWR on 27.115 ~ 1.2
SWR on 28.360 ~ 1.1 to 1.3 with my MFJ Versa Tuner V
The simplicity and ease of assembly of this beam antenna is GREAT for the first time BEAM user or the more experienced user.
Sorry never used any of the SIRO antennas.
Hope this help's,
Lon ~ Tech808 ~ N9CEF
CEF#808 ~ CEF HAM#33 ~ CVC#002
Tech808@copperelectronics.com
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Patzerozero
Senior Member
Username: Patzerozero
Post Number: 3828
Registered: 7-2004
| | Posted on Friday, June 29, 2007 - 5:06 pm: |
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thankyou, Lon, now i have to think about the new beam's problems for my particular project due to the PRE-SET holes.....unfortunately, that MAY not help in this build as i'm am going to need to adjust spacing for optimum performance. BUT, i am glad i know that info prior to a purchase. then again, the mfj 1762 6 meter yagi i have also uses PRE-SET holes, & i already devised a way to adjust spacing, so MAYBE i can get the new ones to work  ....
marconi....i looked at a commercially-built, no-trap, single-feed multi band yagi & tried to input calculations into EZNEC....THAT was a nightmare! EZNEC would NOT show the antenna loading anywhere near the bands it was MANUFACTURED for, so, the single-feed idea i gave up on. again, with the difference in harmonic relationship between the 2 bands i want to use (10.5m & 6m), i THINK i can keep interaction to a very bare minimum. my biggest challenge i think is going to find the optimum spacing & correct element DIAMETER to allow enough bandwidth for 10 & 11. EZNEC was used just to see if the program would show resonance & ANY kind of yagi-like performance. a bit of help from somebody schooled in that program helped me attain a 'yes, probably' response. he told me i may be better off upgrading my mfj259 to a 259b for ease of determining importance of figures, so i may just do that. it was also at his recommendation that i put the 10/11m antenna on a boom 14' or longer-the wider spacing would help with the addition of three 6 meter elements & lessen the possibilty of interaction. fed through either a gamma or beta match was his last recommendation, rather then any sort of direct or balun fed arrangement so i would have more room for error/adjustment while keeping interaction minimal & still have gain & rejection.
anyway, i've built, rebuilt & modded 11m beams before, & i've played around with this 6 meter mfj beam i have, comparing over the air signal changes to known stations (much as your a99/.64 comparison) with various spacing. so right now i am trying to decide which 11m 4 element yagi to buy. i've priced material locally, & unfortunately, 16' of 2" diameter, decent thickness walled aluminum tube will cost me nearly $100, & four 4' pieces not much less, PLUS taking into account weakness of the joints....that's why i'm trying to decide which commercial CB yagi to use as a starting point.
again, remember my biggest concern-not HAVING to use a tuner. a good tuner will allow a radio to fully load into....a tree. but, just how effective as a radiator is that tree? not at all. might as well put that 100 watts into a dummy load-it'll probably get out farther! |
Hyperno_1979
Intermediate Member
Username: Hyperno_1979
Post Number: 365
Registered: 12-2005
| | Posted on Friday, June 29, 2007 - 10:39 pm: |
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Pat,
From what i hear is Maco are out of business. Apparently you can't even buy spare parts for a Maco anymore. Keep an eye out for a new line of antennas Copper Electronics will be carrying, from what i have read and heard they out perform just about every other antenna on the market and are built to "LAST".
CEFFFCEF
Bob
CEF703/CVC26
269 Hunter Valley
27.355 lsb.
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Tech808
Moderator
Username: Tech808
Post Number: 13980
Registered: 8-2002
| | Posted on Saturday, June 30, 2007 - 5:00 am: |
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Pat & Bob,
After talking with the Forummaster late thursday night even though MACO is out of business he is still expecting a large shipment of most all left over antennas and part's from MACO.
I will keep everyone posted on any furture updates.
Lon ~ Tech808 ~ N9CEF
CEF#808 ~ CEF HAM#33 ~ CVC#002
Tech808@copperelectronics.com
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Hyperno_1979
Intermediate Member
Username: Hyperno_1979
Post Number: 370
Registered: 12-2005
| | Posted on Sunday, July 01, 2007 - 1:22 am: |
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Thank you for that Lon, as the 3 ele i am building is a copy of the Maco 103 and i was going to use the gamma match off that antenna. I started to panic as the antenna is about 1/2 built and as Maco are gone i have no idea what gamma match i could use in it's place.
CEFFFCEF
Bob
CEF703/CVC26
269 Hunter Valley
27.355 lsb.
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Patzerozero
Senior Member
Username: Patzerozero
Post Number: 3833
Registered: 7-2004
| | Posted on Sunday, July 01, 2007 - 9:17 am: |
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i've duplicated the maco gamma before, bob. it tunes SLIGHTLY different, but it works.
take a piece of 9913 coax-something double shielded with a solid center conductor-about 12" long TO START with. then, get a piece of aluminum tube, approx 18" long, that this piece of coax will slide neatly inside of. it can't be too tight or too loose. PRESTO. there is your gamma match. start with something a bit longer then maco's gamma match overall, & adjust from there. an analyzer works best, because this homebrew piece has different R & X characteristics when adjusting it then maco's gamma. some playing & it will tune. |
Hyperno_1979
Intermediate Member
Username: Hyperno_1979
Post Number: 371
Registered: 12-2005
| | Posted on Tuesday, July 03, 2007 - 2:09 am: |
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Much appreciated there young Pat. I was starting to wonder what to do with the tubing. It's still only 1/2 built and wasn't real enthusiastic about changing the design at this stage.
CEFFFCEF
Bob
CEF703/CVC26
269 Hunter Valley
27.355 lsb.
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