Jumper was 1 foot.
73, Pete N4ZR
Check out the Reverse Beacon Network
at <http://reversebeacon.net>, now
spotting RTTY activity worldwide.
For spots, please use your favorite
"retail" DX cluster.
On 8/21/2019 12:47 PM, WW3S wrote:
Where did you connect the analyzer? You want it as close as possible to the
feed point, with as little length of coax jumper as possible. Even a 6 ft
jumper can skew the results, been there done that....
Sent from my iPad
On Aug 21, 2019, at 12:36 PM, Jeff Blaine <KeepWalking188@ac0c.com> wrote:
An inverted L without radials is a random length wire and the measurements are
of no meaning until there is a ground system to make up the other half of the
antenna.
But to Wes point, the 259 and big 160m antennas is a recipe for going nuts.
You don't even need a high powered BC station - even a low powered station a
pretty far distance away can cause the 259 to give results in error. A VNA or
something like the Rig Expert are FAR more robust in this application.
73/jeff/ac0c
alpha-charlie-zero-charlie
www.ac0c.com
On 8/21/19 12:04 AM, Wes wrote:
How many high-powered BC stations do you have around?
Wes N7WS
On 8/21/2019 8:55 AM, N4ZR wrote:
I just put up an inverted L, with a vertical length of about 60 feet, and a
total of 135 feet. It is fed through 16 turns of RG-400 on a ferrite core at
the base. There are, as yet, no radials.
Because I was impatient to see what was going on, I grounded the shield to a
single copper-plated ground rod and connected my MFJ259B. I expected a high R
value, and I got one - 112-122 ohms. But surprisingly (to me), lowest SWR was
at 2.070 MHz, and X remained at zero over quite a wide range - all the way down
to about 1.7 MHz.
Is this all to be expected? I plan to put down at least minimum radials in the
next few days, and would expect the R value to drop as I do so. Am I off-base?
_________________
Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
_________________
Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
_________________
Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
_________________
Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
|