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-   -   PA0RDT-Mini-Whip (https://www.radiobanter.com/shortwave/107968-pa0rdt-mini-whip.html)

Steve October 26th 06 06:44 PM

PA0RDT-Mini-Whip
 
I picked one of these up because it's received really solid reviews
from a lot of people. So far I have been using it on the tropical bands
and I have to say I'm disappointed. At my location (Brooklyn) its
performance is consistently inferior to that of my LF Engineering H-800
"Skymatch" and Wellbrook ALA-330S loop (which isn't really at its best
on the tropical bands).

I have to believe that there's something about my location or setup
that prevents the mini-whip from realizing its full potential. Although
lots of people complain about its being a noisy antenna, I don't find
it to be any more prone to noise pickup than the H-800. While I found
its performance to lag behind that of the H-800, I'd say it was
comparable to some of the other active whips I've used over the years.
For the money, it's still a good value, but I frankly cannot imagine
this antenna being competitive with a beverage antenna or large scale
loop.

And yet....plenty of credible people report that the mini-whip IS
competitive in this field.

What can I say? I just report on what I find in my tiny little corner
of the universe.

Steve


[email protected] October 26th 06 07:25 PM

PA0RDT-Mini-Whip
 

Steve wrote:
I picked one of these up because it's received really solid reviews
from a lot of people. So far I have been using it on the tropical bands
and I have to say I'm disappointed. At my location (Brooklyn) its
performance is consistently inferior to that of my LF Engineering H-800
"Skymatch" and Wellbrook ALA-330S loop (which isn't really at its best
on the tropical bands).

I have to believe that there's something about my location or setup
that prevents the mini-whip from realizing its full potential. Although
lots of people complain about its being a noisy antenna, I don't find
it to be any more prone to noise pickup than the H-800. While I found
its performance to lag behind that of the H-800, I'd say it was
comparable to some of the other active whips I've used over the years.
For the money, it's still a good value, but I frankly cannot imagine
this antenna being competitive with a beverage antenna or large scale
loop.

And yet....plenty of credible people report that the mini-whip IS
competitive in this field.

What can I say? I just report on what I find in my tiny little corner
of the universe.

Steve


Like most active antennas, the PAORDT suffers from serious common mode
susceptability issues. It is really only half of an antenna because it
doesn't
include a real ground and instead uses the outside of the coax for
that.

By mounting one on a 8' ground rod in moise soil and adding enough
ferrite
beads to choke off common mode noise this antenna does an aceptable, if
not respectable job.

Terry


John Plimmer October 26th 06 09:00 PM

PA0RDT-Mini-Whip
 
I have one of these and must say I am disappointed with it. Some of my mates
have it and rave about it as if it was the best thing since sliced jerky
came along.

I find the signal pickup weak and it sucks up the local noise like a vacuum
cleaner. It's not a patch on my outstanding RF Systems DX-1 Pro, but then I
guess it wouldn't be as the DX-1 costs 17 times more..........

--
John Plimmer, Montagu, Western Cape Province, South Africa
South 33 d 47 m 32 s, East 20 d 07 m 32 s
RX Icom IC-756 PRO III with MW mods
Drake SW8 & ERGO software
Sony 7600D, GE SRIII, Redsun RP2100
BW XCR 30, Sangean 803A.
GE circa 50's radiogram
Antenna's RF Systems DX 1 Pro, Datong AD-270
Kiwa MW Loop, PAORDT Roelof mini-whip
http://www.dxing.info/about/dxers/plimmer.dx

"Steve" wrote in message
ups.com...
I picked one of these up because it's received really solid reviews
from a lot of people. So far I have been using it on the tropical bands
and I have to say I'm disappointed. At my location (Brooklyn) its
performance is consistently inferior to that of my LF Engineering H-800
"Skymatch" and Wellbrook ALA-330S loop (which isn't really at its best
on the tropical bands).

I have to believe that there's something about my location or setup
that prevents the mini-whip from realizing its full potential. Although
lots of people complain about its being a noisy antenna, I don't find
it to be any more prone to noise pickup than the H-800. While I found
its performance to lag behind that of the H-800, I'd say it was
comparable to some of the other active whips I've used over the years.
For the money, it's still a good value, but I frankly cannot imagine
this antenna being competitive with a beverage antenna or large scale
loop.

And yet....plenty of credible people report that the mini-whip IS
competitive in this field.

What can I say? I just report on what I find in my tiny little corner
of the universe.

Steve




Yodar October 27th 06 05:57 PM

PA0RDT-Mini-Whip
 


By mounting one on a 8' ground rod in moise soil and adding enough ferrite
beads to choke off common mode noise this antenna does an aceptable, if
not respectable job.

Terry




Terry,
I am working off a vertical with active antenna properties.

Pray tell, where/how are the ferrite beads installed and their vendor and
part no?

yodar



[email protected] October 27th 06 07:08 PM

PA0RDT-Mini-Whip
 

Yodar wrote:
By mounting one on a 8' ground rod in moise soil and adding enough ferrite
beads to choke off common mode noise this antenna does an aceptable, if
not respectable job.

Terry




Terry,
I am working off a vertical with active antenna properties.

Pray tell, where/how are the ferrite beads installed and their vendor and
part no?

yodar

Seehttp://www.yccc.org/Articles/W1HIS/C...S2006Apr06.pdf .

On page 6 he explains the different mixes.
As a ham, Chuck/W1HIS has to be concerned about the wrong ferrite
getting too hot and bad things, like a fire, happening. For us SWL
types, "bad" ferrite has more loss and can be a good thing. If you read
his pdf he explains the logic of how and why.


I have salvaged nearly 1000 various ferrite beads, or as Will calls
them, sleeves from
PCs, VGA monitors, on the power and video cable, printer cables. I had
access to a
metal salvage/recylcer and was allowed all of the cut off cables a man
could want.

If I wanted to do the job with store bought ferrite I would want to
cover the 100KHz through 30MHz range. I would most likely use mix 31.
In both of the commercial receiving set ups I built I used mix 31. The
trick is to use enough ferrite to give at least 1K Z at the lowest
frequency of interest. This can be accomplished with perhjaps 30 run of
the mill, unkown
sleeves, or 10 to 15 of the mixture 31.

To use them you simply remove the RF connector, slide on the sleeves or
torroids, and reinstall, a use a new, RF connector. You can also cheat
and use John Bryant's
method. See http://www.dxing.info/equipment/coax_leadin_bryant.pdf.

John's method make more sense becuase you can build the chokes and add
them to the
existing coax. If I were doing another commercial install I would in
all likelyhood go with
John's becuase it would be easy to build several chokes and add as many
as you needed.

But as W1HIS says, "hams are the cheapest people around", and I like to
waste my
money on other toys. From a practical point both methods will work
very well. I tend
to like distributing my ferrite beads/sleeves a long the length of the
cable to spread the
induction out. I have found this to be, maybe, more effective in
eleminating Transferr
Impedance. Coax isn't perfect and under the right, or more properly,
wrong condition,
TI can allow out side signals to intrude into the coax. Not all that
common and you
will only notice it after you have reduced all the other RFI to a low
level.

I hope this helps.

Terry



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