On 8/11/2012 5:00 AM, Pete Smith N4ZR wrote:
> I'm not sure I'd go too far with the FCC map. At my QTH, which is shown
> as average, actual ground/earth varies within a hundred feet from deep
Yes, but I have also measured the current drop off with distance
on my beverages and it agrees with the h
> This for instance
> http://www.aytechnologies.com/TechData/ShortBev.htm
There isn 't enough detail in the description to understand the model and
the plots fully.
A 560 foot long "beverage" on 175 kHz has about 15 dB null off the sides at
5 degrees wave angle, and a few dB F/B at low angles.
Please elaborate! The LF stations you are likely to receive would all be
from Europe or Mediteranean countries in N. Africa. From your location,
I wonder how you would get enough directivity to separate them.
Chuck
On 8/11/2012 9:40 AM, ZR wrote:
> And what mode is that? Yes they work suprisin
On Sat, 2012-08-11 at 09:44 -0400, Tom W8JI wrote:
---snip---
>
> Mostly what we find, when we cut through all the emotion, is we try to find
> a way to justify why our locations and antennas are somehow "special".
---snip---
> 73 Tom
>
Hi,
My antennas are indeed special. They fit in a rec
- Original Message -
From: "Tom W8JI"
To:
Sent: Saturday, August 11, 2012 11:43 AM
Subject: Re: Topband: RX 4 SQ Phasing
>> ** That doesnt make sense since the books, etc claim virtually no
>> directivity at a 1/4 wave. At 175 KHz a 1/4 wave is 1406'.
>
> ** That doesnt make sense since the books, etc claim virtually no
> directivity at a 1/4 wave. At 175 KHz a 1/4 wave is 1406'.
I don't know what "books, etc" that comes from, but even over fairly good
soil a 600-foot "Beverage" models to have about 18 dB side null and a few dB
F/B at 175 kHz.
- Original Message -
From: "Tom W8JI"
To:
Sent: Friday, August 10, 2012 11:45 PM
Subject: Re: Topband: RX 4 SQ Phasing
> >I use 5 two wire Beverages for 10 directions and have good directivity
> >down
>> to the 175 KHz LF BCB and they are only 500-700&#x
> I'm not sure I'd go too far with the FCC map. At my QTH, which is shown
> as average, actual ground/earth varies within a hundred feet from deep
> old riverbottom loam to limestone with a thin covering of topsoil (or
> sometimes none). While I don't know how this affects electrical ground
> con
>>>N4ZR wrote:
>>>I'm not sure I'd go too far with the FCC map.
You might look at your local soil surveys for better information, or contact
your local NRCS office.
I use the online Web Soil Survey.
http://websoilsurvey.nrcs.usda.gov/app/HomePage.htm
Once you select your area of interest and yo
I'm not sure I'd go too far with the FCC map. At my QTH, which is shown
as average, actual ground/earth varies within a hundred feet from deep
old riverbottom loam to limestone with a thin covering of topsoil (or
sometimes none). While I don't know how this affects electrical ground
condition
>I use 5 two wire Beverages for 10 directions and have good directivity down
> to the 175 KHz LF BCB and they are only 500-700' long. Performance seems
> to
> exceed published info. On the US BCB its like aiming a long yagi on 2M,
> multiple stations on the same frequency can be heard with ease du
How does it work way down into LF?
Carl
- Original Message -
From: "Rick Karlquist"
To: "ZR"
Cc: ;
Sent: Friday, August 10, 2012 8:14 PM
Subject: Re: Topband: RX 4 SQ Phasing
> ZR wrote:
>>
>> Sometimes I wonder if its my very poor RF ground co
ZR wrote:
>
> Sometimes I wonder if its my very poor RF ground conditions that tilt the
> wave more and result in the performance of a much longer antenna.
>
> Carl
> KM1H
My ground is high conductivity according to the FCC map, so
maybe that doesn't explain the performance.
Rick
N6RK
__
uot;Dennis W0JX"
Sent: Friday, August 10, 2012 1:59 PM
Subject: Re: Topband: RX 4 SQ Phasing
Larry Molitor wrote:
> However, the lower frequency limit of usefulness extends WAY below the AM
> broadcast band. For example I currently use a two element Hi-Z array with
> 60 foot spacin
Larry Molitor wrote:
> However, the lower frequency limit of usefulness extends WAY below the AM
> broadcast band. For example I currently use a two element Hi-Z array with
> 60 foot spacing and can see as much as 30 dB F/B as low as 150 kHz!. The
A while back, I built a 4X2 low band array of rec
Dennis, W0JX, is nearly correct but didn't go far enough.
In the last few years I've had up several Hi-Z two element arrays, a Hi-Z 4-sq,
and a Hi-Z 2-3 array. They all exhibit the same characteristics. Depending on
the element spacing used, the upper frequency limit may be over 7 MHz. For
inst
Bob, for a good understanding of the concepts of phasing in these RX antennas,
read Chapter Seven of ON4UN's "Low Band DXing." The length of the delay lines
primarily affects the placement of the nulls of the array while the voltage
output of the antennas and amplifiers controls the depth of th
17 matches
Mail list logo
