Reply
 
LinkBack Thread Tools Search this Thread Display Modes
  #1   Report Post  
Old February 1st 05, 01:24 AM
Vinnie S.
 
Posts: n/a
Default Need help with high SWR

A bunch of people have been helping me here with this. I got my setup running,
but have a high SWR on the CB band. Here are the parameters:


My SWR is 1.5 on channel 1, and 3 on channel 40.


1. I have a a 6 foot Firestik in the attic. I am using 8 pieces of 10 gauge
wire, all 102" long, as a ground plane connected to the mounting stud.

2. The mounting stud and ground plane wires are not connected to earth ground.
There is no way I can get a ground rod into the frozen ground. Not at least for
a few weeks.

3. I am using 50' of LMR-400 coax. No shorts measured.

4. I have a RF choke/balun of about 8 turns, 8 inches round, about 2 inches
below the antenna and ground plane wires. I cannot get it any lower.

5. The radio is a HR-2510, and that is not grounded for the same reason as #2.


I did a frequency check to see where this antenna is tuned. It seems to be tuned
for 26.500-26.800 MHz. The SWR is a flat 1.2 across that band. It starts to
when I go below or above that band.

I wanted to know if there is anything I should do before I cut the wire on the
Firestik. Would grounding the ground plane or the radio to a ground rod help?

And suggestions are appeciated.

Vinnie S.

  #2   Report Post  
Old February 1st 05, 01:45 AM
U Know Who
 
Posts: n/a
Default


"Vinnie S." wrote in message
...
A bunch of people have been helping me here with this. I got my setup
running,
but have a high SWR on the CB band. Here are the parameters:


My SWR is 1.5 on channel 1, and 3 on channel 40.


1. I have a a 6 foot Firestik in the attic. I am using 8 pieces of 10
gauge
wire, all 102" long, as a ground plane connected to the mounting stud.

2. The mounting stud and ground plane wires are not connected to earth
ground.
There is no way I can get a ground rod into the frozen ground. Not at
least for
a few weeks.

3. I am using 50' of LMR-400 coax. No shorts measured.

4. I have a RF choke/balun of about 8 turns, 8 inches round, about 2
inches
below the antenna and ground plane wires. I cannot get it any lower.

5. The radio is a HR-2510, and that is not grounded for the same reason as
#2.


I did a frequency check to see where this antenna is tuned. It seems to be
tuned
for 26.500-26.800 MHz. The SWR is a flat 1.2 across that band. It starts
to
when I go below or above that band.

I wanted to know if there is anything I should do before I cut the wire on
the
Firestik. Would grounding the ground plane or the radio to a ground rod
help?

And suggestions are appeciated.

Vinnie S.


This may seem overly simplistic or stupid, but try removing the plastic cap
on the end of the antenna. It affected my SWR on one I had. I can't remember
which way, but I do remember it made a difference.


  #3   Report Post  
Old February 1st 05, 01:58 AM
Vinnie S.
 
Posts: n/a
Default

On Tue, 01 Feb 2005 00:45:57 GMT, "U Know Who" wrote:



3. I am using 50' of LMR-400 coax. No shorts measured.

4. I have a RF choke/balun of about 8 turns, 8 inches round, about 2
inches
below the antenna and ground plane wires. I cannot get it any lower.

5. The radio is a HR-2510, and that is not grounded for the same reason as
#2.


I did a frequency check to see where this antenna is tuned. It seems to be
tuned
for 26.500-26.800 MHz. The SWR is a flat 1.2 across that band. It starts
to
when I go below or above that band.

I wanted to know if there is anything I should do before I cut the wire on
the
Firestik. Would grounding the ground plane or the radio to a ground rod
help?

And suggestions are appeciated.

Vinnie S.


This may seem overly simplistic or stupid, but try removing the plastic cap
on the end of the antenna. It affected my SWR on one I had. I can't remember
which way, but I do remember it made a difference.



Correct. That is what is on the Firestik website too. But it was so out of wack
on 27 MHz, I was wonder is I did something wrong. I wanted to see what people
had to say before I cut it.

Vinnie S.
  #4   Report Post  
Old February 1st 05, 02:13 AM
 
Posts: n/a
Default

A bunch of people have been helping me here with this. I got my setup running,
but have a high SWR on the CB band. Here are the parameters:


My SWR is 1.5 on channel 1, and 3 on channel 40.


1. I have a a 6 foot Firestik in the attic. I am using 8 pieces of 10 gauge
wire, all 102" long, as a ground plane connected to the mounting stud.

2. The mounting stud and ground plane wires are not connected to earth ground.
There is no way I can get a ground rod into the frozen ground. Not at least for
a few weeks.

3. I am using 50' of LMR-400 coax. No shorts measured.

4. I have a RF choke/balun of about 8 turns, 8 inches round, about 2 inches
below the antenna and ground plane wires. I cannot get it any lower.

5. The radio is a HR-2510, and that is not grounded for the same reason as #2.


I did a frequency check to see where this antenna is tuned. It seems to be tuned
for 26.500-26.800 MHz. The SWR is a flat 1.2 across that band. It starts to
when I go below or above that band.

I wanted to know if there is anything I should do before I cut the wire on the
Firestik. Would grounding the ground plane or the radio to a ground rod help?

And suggestions are appeciated.

Vinnie S.



Dude, you are using a keyclown radio on illegal frequencies. Get a stock
radio and you'll get help.


  #5   Report Post  
Old February 1st 05, 02:20 AM
 
Posts: n/a
Default


I did a frequency check to see where this antenna is tuned. It seems to be tuned
for 26.500-26.800 MHz. The SWR is a flat 1.2 across that band. It starts to
when I go below or above that band.


Because of the close proximity of the roof structure inside the attic
you are adding more capacitance to the antenna than what would
normally be there.

In order to bring the antenna back into resonance you'll need to
counteract the increased capacitance by decreasing the inductance.

This is done by shortening the antenna.

I don't believe you'll ever be able to get your match as low as you
could in free air. This is because you'll get more induced antenna
currents whenever the antenna is located inside a house.




  #8   Report Post  
Old February 1st 05, 12:56 PM
Steveo
 
Posts: n/a
Default

Vinnie S. wrote:
I got it down to 1.5 on 40, and 1.3 on 1. I can probably get it down to
1.3 on 40, and that is it.

Vinnie S.

Cool. Made any contacts yet?
  #9   Report Post  
Old February 1st 05, 02:24 PM
Jay in the Mojave
 
Posts: n/a
Default

Hello Vinnie:

If that antenna doesn't work, maybe a out side stealth small gauge wire
vertical dipole will work great, if you have some tree's around.

Jay in the Mojave

Kreedentials:
Rock & Roll Fan, C&W too, have bitchen outside speakers
Owner 1977 Ford F250 4x4 Truck, 460 Hi-Po Engine set ya back in the
seat, no smog ****
Member Mojave Desert Radio Association, 9dollrs
I use my Liberal Arts Collage Catalog as a back stop on my drill press

Vinnie S. wrote:

A bunch of people have been helping me here with this. I got my setup running,
but have a high SWR on the CB band. Here are the parameters:


My SWR is 1.5 on channel 1, and 3 on channel 40.


1. I have a a 6 foot Firestik in the attic. I am using 8 pieces of 10 gauge
wire, all 102" long, as a ground plane connected to the mounting stud.

2. The mounting stud and ground plane wires are not connected to earth ground.
There is no way I can get a ground rod into the frozen ground. Not at least for
a few weeks.

3. I am using 50' of LMR-400 coax. No shorts measured.

4. I have a RF choke/balun of about 8 turns, 8 inches round, about 2 inches
below the antenna and ground plane wires. I cannot get it any lower.

5. The radio is a HR-2510, and that is not grounded for the same reason as #2.


I did a frequency check to see where this antenna is tuned. It seems to be tuned
for 26.500-26.800 MHz. The SWR is a flat 1.2 across that band. It starts to
when I go below or above that band.

I wanted to know if there is anything I should do before I cut the wire on the
Firestik. Would grounding the ground plane or the radio to a ground rod help?

And suggestions are appeciated.

Vinnie S.

Reply
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules

Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Announcing 'hifi-am', to discuss High Fidelity AM tuners and hobbyist transmitters Jon Noring General 1 July 9th 04 07:25 AM
Announcing 'hifi-am', to discuss High Fidelity AM tuners and hobbyist transmitters... Jon Noring Broadcasting 0 July 9th 04 01:44 AM
Announcing 'hifi-am', to discuss High Fidelity AM tuners and hobbyist transmitters Jon Noring Homebrew 0 July 8th 04 07:49 PM
High school radio stations alive and well Mike Terry Broadcasting 4 May 25th 04 03:55 PM
Because I Got High-Michael Bryant DxAce Shortwave 15 March 12th 04 09:41 AM


All times are GMT +1. The time now is 07:17 PM.

Powered by vBulletin® Copyright ©2000 - 2021, Jelsoft Enterprises Ltd.
Copyright 2004-2021 RadioBanter.
The comments are property of their posters.
 

About Us

"It's about Radio"

 

Copyright © 2017