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]   Go Down
  Print  
Author Topic: Installing antenna on a (plastic) Saturn vue?  (Read 813 times)
AB2MH
Member

Posts: 263


WWW

Ignore
« on: August 12, 2006, 04:10:39 AM »

A friend of mine recently bought a little Tarheel II screwdriver.  He mounted it on his Saturn Vue's rear door using the K400 mount.

The vehicle appears to be mostly plastic/fiberglass, unfortunately, so grounding is a problem.  The roof and some other parts appear to be metal though.  

He's getting good output on the lower bands but on 6m the rig is folding back the power (Icom 706).

I told him to bond the metal parts of the vehicle better using wide, flat braid and see if he can get the base of the whip at least over the roofline.

Anything else I'm missing?

Also, has anyone installed a tarheel on their Saturn Vue?
Logged
K0BG
Member

Posts: 9833


WWW

Ignore
« Reply #1 on: August 12, 2006, 07:37:22 AM »

It isn't a DC ground that you need, it is a ground plane. In short terms, there must be as much metal under the antenna as possible, and a simple ground strap is not a substitute!

The fact that most of the body is plastic, makes HF mobile an iffy situation at best. Specially designed VHF antennas are available that do not require much of a ground plane, so they work passably. This is not the case with HF. The fact the SWR is low, has zero relationship to how efficient an antenna is or isn't.

Alan, KØBG
www.k0bg.com
Logged

KG4RUL
Member

Posts: 2676


WWW

Ignore
« Reply #2 on: August 12, 2006, 08:56:10 AM »

I have very similar setup on my Saturn VUE, the only difference being I use a Comet mount.  It does work though not with stellar performance.  I ran grounding straps around the rear hatch hinges and to the base of the antenna mount.  Lots of ferrites on the various radio wires and it seems to work fairly well.  The biggest problem to solve was noise from the electric power steering motors as they got older.

Dennis KG4RUL
Logged
AB2MH
Member

Posts: 263


WWW

Ignore
« Reply #3 on: August 12, 2006, 12:09:45 PM »

Okay, but he was using a hamstick before with good enough results (for a hamstick anyway).  

The only problem he seems to be having is 6 meters.

So any ideas?
Logged
AB2MH
Member

Posts: 263


WWW

Ignore
« Reply #4 on: August 12, 2006, 12:19:06 PM »

K0BG wrote:

> It isn't a DC ground that you need, it is a ground
> plane. In short terms, there must be as much metal
> under the antenna as possible, and a simple ground
> strap is not a substitute!

Right you are, Alan.  However the only place where I see a lot of metal is the roof, and the best overall solution is to somehow mount the antenna on the roof (which appears to be metal).  But that means he has to either use a mag mount or drill a hole.  And I don't think drilling a hole is a solution for that heavy antenna.  

So that leaves us with the rear hatch, which is half metal and half glass.  

After last night where I scraped off some paint and made sure that the mount was making better contact with the paint, we did get some better results.  The antenna will now load up on 40 and 80 as well as the higher bands, which it did not do before.

However, 6M is still problematic.  While the SWR is low on 6M, when he modulates the rf out isn't full power.  It's much less than on the lower bands.  

> The fact that most of the body is plastic, makes HF
> mobile an iffy situation at best. Specially designed
> VHF antennas are available that do not require much
> of a ground plane, so they work passably. This is not
> the case with HF. The fact the SWR is low, has zero
> relationship to how efficient an antenna is or isn't.

I agree, but he did use an outbacker and a hamstick before, and the only problem he seems to be having now is getting 6M to work properly.

I'm thinking RF is getting in somewhere, so I told him to get some split beads and bead up all of his cables. I don't believe that RF is getting into the audio because the audio sounds fine (I verified with my rig).    However that is something to look into.

I also directed him to your website to see if he can find out anything else there.
Logged
K0BG
Member

Posts: 9833


WWW

Ignore
« Reply #5 on: August 12, 2006, 03:40:26 PM »

Ryan, I try to cover all of the ground I can on my web site. The problem is, there are literally hundreds of different antennas, radios, cars, trucks, and even golf carts, that to cover a specific case is all but impossible.

That said, there are several rather basic concepts which need to be followed if one wishes to have any modicum of efficiency. You can go the minimum by using a Maxx-Comm 50 ohm resistor hooked to an 8 foot whip, and mount it any old way you want, and you will make contacts. But when you compare this to a decent installation replete with bonding, wiring, etc., using a decent antenna, the difference is flat astounding! In other words, it is the EXTENT you are willing to go that counts.

Nonetheless, the basics are still important. Placing as much metal under the antenna as possible, as high as possible, and as clear as possible are the prime considerations. Anything less is just that; less!

Alan, KØBG
www.k0bg.com
Logged

WA4MJF
Member

Posts: 1003




Ignore
« Reply #6 on: August 20, 2006, 08:16:26 AM »

A little late now, but next car
make sure it's made of metal before you
buy it.  That would solve the problem
in the future.

Besides, in case of accident, you'd be safer
surrounded by metal rather than plastic/
fiberglass.

73 de Ronnie
Logged
AB2MH
Member

Posts: 263


WWW

Ignore
« Reply #7 on: August 20, 2006, 01:57:41 PM »

Well it's not my car.  I have a 2004 Honda Accord which I must say is a very nice vehicle in terms of having low noise and good shielding.

Anyway, I met the owner of the Vue yesterday.

He said that with some bonding with flat braid he got better results. The biggest improvement was when he bonded the engine to the body.  Now he's going to choke his cables including the separation cables.

I suspect RF is getting in somewhere.  Choking the cables should minimize entry points for rectified RF.
Logged
WB2LCW
Member

Posts: 108


WWW

Ignore
« Reply #8 on: August 29, 2006, 11:29:50 AM »

Has anyone thought of or tried spraying conductive
paint on the inside of the trunk and using fimger stock to ground it to the frame?
Logged
AB2MH
Member

Posts: 263


WWW

Ignore
« Reply #9 on: August 29, 2006, 11:46:47 AM »

Nope but that is an interesting idea.
Logged
Pages: [1]   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!