Call Search
     

New to Ham Radio?
My Profile

Community
Articles
Forums
News
Reviews
Friends Remembered
Strays
Survey Question

Operating
Contesting
DX Cluster Spots
Propagation

Resources
Calendar
Classifieds
Ham Exams
Ham Links
List Archives
News Articles
Product Reviews
QSL Managers

Site Info
eHam Help (FAQ)
Support the site
The eHam Team
Advertising Info
Vision Statement
About eHam.net

   Home   Help Search  
Pages: [1] 2 Next   Go Down
  Print  
Author Topic: How to squeeze more range out of a 2 meter beam?  (Read 5734 times)
WALTERB
Member

Posts: 528




Ignore
« on: May 30, 2013, 12:42:01 PM »


I picked up a Diamond 10 element beam at Dayton.  Put it on my roof as high as it would safely go.
Fed it with RG-213.
Vertically mounted it.
Besides moving it higher, what else can I do to get some more range out of it, and what sort of range (in miles) should I expect from it under normal band conditions?

Thanks.
Logged
AD4U
Member

Posts: 2186




Ignore
« Reply #1 on: May 30, 2013, 01:29:13 PM »

Walterb I honestly do not know of ANY way to squeeze any more range out of your beam other than raising it higher.  More power will not noticeably increase range, and if it does you will talk further than you can hear.

Dick  AD4U
Logged
AA4PB
Member

Posts: 13032




Ignore
« Reply #2 on: May 30, 2013, 01:49:21 PM »

The range depends a whole lot on what the other station has. If he has an HT with a rubber duck you won't get much range to him. If he has 20 elements on a 100 foot tower then the range will be a lot more. Range also depends on the terrain, signal blockages, etc. There are so many variables that it is difficult to provide a "typical" range with any degree of accuracy. Even if you stack a second beam you only get a little less than 3dB gain which isn't going to make any massive improvement in range.

On VHF, the only way to get a significant increase is to raise the antenna higher.
Logged
WALTERB
Member

Posts: 528




Ignore
« Reply #3 on: May 30, 2013, 01:51:39 PM »

Walterb I honestly do not know of ANY way to squeeze any more range out of your beam other than raising it higher.  More power will not noticeably increase range, and if it does you will talk further than you can hear.

Dick  AD4U

thanks. I was just wondering if I was missing something.  The coax is as short as I can make it.

What kind of range should I expect?  I could hit repeaters 100+ miles away, but couldn't hold them.  The ones within 50 miles are fine. 

thanks.
Logged
WALTERB
Member

Posts: 528




Ignore
« Reply #4 on: May 30, 2013, 01:53:36 PM »

The range depends a whole lot on what the other station has. If he has an HT with a rubber duck you won't get much range to him. If he has 20 elements on a 100 foot tower then the range will be a lot more. Range also depends on the terrain, signal blockages, etc. There are so many variables that it is difficult to provide a "typical" range with any degree of accuracy. Even if you stack a second beam you only get a little less than 3dB gain which isn't going to make any massive improvement in range.

On VHF, the only way to get a significant increase is to raise the antenna higher.


ok, thanks.  I thought that was the case but I thought I would ask.  I'm using a yaesu FT-7800 with ~50 watts. 
Logged
WB2WIK
Member

Posts: 20666




Ignore
« Reply #5 on: May 30, 2013, 03:17:10 PM »

The 10L Diamond 2m yagi is only 7' long and really hasn't much gain.

But installation is very critical.  It should be installed using a standoff bracket (which I think is supplied) off to the "side" of the main rotating mast.  Did you do that?

Height makes might on VHF.  Double antenna height above ground at an average location and you can often double working radius without doing anything else at all.  Doubling the radius increases the number of stations available to work by a square function, or a factor of 4x.  That's a rather enormous difference.

Using a better beam also helps.  For example, the M2 model 2M9 is 14-1/2' long and has about 4 dB more gain than the Diamond 10L does.  That's a lot, and it's still a very lightweight antenna (a few pounds), just much more optimized.  And of course with that gain comes a narrower pattern, so rotator steering becomes more critical.
Logged
WX7G
Member

Posts: 6328




Ignore
« Reply #6 on: May 30, 2013, 03:27:04 PM »


[/quote]
 I could hit repeaters 100+ miles away, but couldn't hold them.  The ones within 50 miles are fine. 

[/quote]

Is the repeater full quieting at your QTH? If so you need more TX power, if not you need to get the antenna up higher.
Logged
KA4POL
Member

Posts: 2125




Ignore
« Reply #7 on: May 30, 2013, 10:15:14 PM »

The antenna has a gain of roughly 9.5 dB. They usually give the higher dBi value.
On higher frequencies it depends very much on your location, i.e. up on a hill or down in the valley. If you are getting signals via reflection it may make a difference to mount the antenna horizontally.So a general statement on distances to be reached is almost impossible.
You also did not mention what equipment you are using, i.e. power and RX quality play a role too.
Logged
WALTERB
Member

Posts: 528




Ignore
« Reply #8 on: May 31, 2013, 06:38:33 AM »

The 10L Diamond 2m yagi is only 7' long and really hasn't much gain.

But installation is very critical.  It should be installed using a standoff bracket (which I think is supplied) off to the "side" of the main rotating mast.  Did you do that?

Height makes might on VHF.  Double antenna height above ground at an average location and you can often double working radius without doing anything else at all.  Doubling the radius increases the number of stations available to work by a square function, or a factor of 4x.  That's a rather enormous difference.

Using a better beam also helps.  For example, the M2 model 2M9 is 14-1/2' long and has about 4 dB more gain than the Diamond 10L does.  That's a lot, and it's still a very lightweight antenna (a few pounds), just much more optimized.  And of course with that gain comes a narrower pattern, so rotator steering becomes more critical.

it claimed 11.6 db gain. No stand off was included, but I used a fiberglass mast, so the result should be about the same correct?
I saw a cushcraft in the auditorium at Dayton. it was about 9 feet long and sagging under its own weight.  that was why I opted for the diamond, but I get your point.
thanks.
Logged
WALTERB
Member

Posts: 528




Ignore
« Reply #9 on: May 31, 2013, 06:39:24 AM »


I could hit repeaters 100+ miles away, but couldn't hold them.  The ones within 50 miles are fine. 

[/quote]

Is the repeater full quieting at your QTH? If so you need more TX power, if not you need to get the antenna up higher.
[/quote]

no none of them were.  Just the local ones.
Logged
WALTERB
Member

Posts: 528




Ignore
« Reply #10 on: May 31, 2013, 06:55:24 AM »

The antenna has a gain of roughly 9.5 dB. They usually give the higher dBi value.
On higher frequencies it depends very much on your location, i.e. up on a hill or down in the valley. If you are getting signals via reflection it may make a difference to mount the antenna horizontally.So a general statement on distances to be reached is almost impossible.
You also did not mention what equipment you are using, i.e. power and RX quality play a role too.

a Yaesu FT-1802 at about 50 watts. I'm in one of the highest areas in the county, but its somewhat flat, so I'm not up on a hill.  The house is a one story ranch with the rotor on the roof  on a 10 foot mast, and the antenna on a 5 foot mast above it. So about 25 feet off the ground.
Logged
AA4PB
Member

Posts: 13032




Ignore
« Reply #11 on: May 31, 2013, 07:30:06 AM »

I think you are doing pretty well at 50 miles. There are a lot of variables in repeaters as well. Some are at 100 feet and some are at 500 feet and some are on top of a mountain. The height of the repeater makes a huge difference.

If you raise your antenna from 25-feet to 75-feet then you'll probably be solid into the 100-mile repeaters.
Logged
WALTERB
Member

Posts: 528




Ignore
« Reply #12 on: May 31, 2013, 07:36:56 AM »

I think you are doing pretty well at 50 miles. There are a lot of variables in repeaters as well. Some are at 100 feet and some are at 500 feet and some are on top of a mountain. The height of the repeater makes a huge difference.

If you raise your antenna from 25-feet to 75-feet then you'll probably be solid into the 100-mile repeaters.


thanks.  I don't know if I'll get a chance to do that. Hopefully someday.

Logged
WB2WIK
Member

Posts: 20666




Ignore
« Reply #13 on: May 31, 2013, 09:06:41 AM »



it claimed 11.6 db gain. No stand off was included, but I used a fiberglass mast, so the result should be about the same correct?
I saw a cushcraft in the auditorium at Dayton. it was about 9 feet long and sagging under its own weight.  that was why I opted for the diamond, but I get your point.
thanks.

The 11.6 dB is dBi, or about 9.5 dBd.  Assuming it's truthful, which I have no idea. Wink

I'm surprised they don't include the standoff bracket, as it's shown in all the literature.

A fibreglas mast should be okay, but remember not to run the coaxial feedline down the mast; otherwise, you just added a "metal mast" to the installation, by virtue of the coax.  Unless it's an "end mount" beam (where the mast is behind the beam, and the whole antenna is to one side of the mast), the coax feedline for a vertically polarized beam should come back off the rear end of the antenna and drop down from there, and not be routed down the mast.  Routing coax down the mast adds an unintended, untuned "element" in the middle of the antenna that shouldn't be there. Smiley

I mentioned M2, not Cushcraft.  M2 is the leader in American-made VHF/UHF beams, for a reason.
Logged
WALTERB
Member

Posts: 528




Ignore
« Reply #14 on: May 31, 2013, 09:40:57 AM »



it claimed 11.6 db gain. No stand off was included, but I used a fiberglass mast, so the result should be about the same correct?
I saw a cushcraft in the auditorium at Dayton. it was about 9 feet long and sagging under its own weight.  that was why I opted for the diamond, but I get your point.
thanks.

The 11.6 dB is dBi, or about 9.5 dBd.  Assuming it's truthful, which I have no idea. Wink

I'm surprised they don't include the standoff bracket, as it's shown in all the literature.

A fibreglas mast should be okay, but remember not to run the coaxial feedline down the mast; otherwise, you just added a "metal mast" to the installation, by virtue of the coax.  Unless it's an "end mount" beam (where the mast is behind the beam, and the whole antenna is to one side of the mast), the coax feedline for a vertically polarized beam should come back off the rear end of the antenna and drop down from there, and not be routed down the mast.  Routing coax down the mast adds an unintended, untuned "element" in the middle of the antenna that shouldn't be there. Smiley

I mentioned M2, not Cushcraft.  M2 is the leader in American-made VHF/UHF beams, for a reason.

thanks. yes, I hadn't heard of M2.  This guy was $69 at Dayton. Thought I would give it a try.  It is and end mount, in that almost all the elements are forward of the driven element, and yes I put the coax (RG-213) down the mast. (oops.. )  Embarrassed

I'll check the M2 out and see if my wee little Radio shack rotor can drive it or not.  I bought a Hy-gain for $100+ from RandL at Dayton, but it failed out of the box, and I have to pay to ship it back.  That's twice with me and RandL and their shan't be a third time.  Cheesy
Logged
Pages: [1] 2 Next   Go Up
  Print  
 
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.11 | SMF © 2006-2009, Simple Machines LLC Valid XHTML 1.0! Valid CSS!