Topband: Waller Flag

[John Harden, D.M.D.]

Without my Hi-Z 8 and the Waller Flag (on a 40 Ft boom at 95 ft) I would not hear squat on 160.
I listen in diversity receive with the K3 and use only the Hi-Z 8 with the IC-7610. However, the IC-7610 is EXTREMELY QUIET!! 

73,

John, W4NU
Atlanta
K4JAG 1959 to 1998

Sent from my iPhone

> On Dec 15, 2018, at 3:05 PM, Stan Stockton <wa5rtg at gmail.com> wrote:
> 
> Thanks, Rick.  I think you are fortunate to have a low noise level where
> you could actually use your TX Antenna.
> 
> My situation is that if I tried to listen on my transmit antenna I would
> only work the very strongest of signals.  Typically the noise moves the
> meter to about 20-25 over S9 if I listen on my vertical.  The best success
> I have had is with a Beverage, but whether on any given trip I can put one
> up largely depends on whether any of the four or five people's property I
> would cross are there and whether they would allow it or complain about
> it.  On my own property, the only thing I have done is put up a little
> triangle with the top at about 20 feet and the bottom wire in the
> neighborhood of 30-35 feet.  That antenna has about -37 dB of gain.  A 15
> dB preamp plus the preamp in the transceiver makes it an OK antenna - good
> enough that I have worked about 250 JA stations none of which would have
> been worked if I were listening on my vertical.  And I am guessing that if
> I had a 3 dB improvement in S/N ratio that I would have worked 400 in the
> same time period.  That antenna has an RDF of 7.7.  Always wanting
> something better and if I could put up something I could rotate with an RDF
> of 11 or so, I would hope to be content.
> 
> Stan
> 
> Stan
> 
> On Sat, Dec 15, 2018 at 1:47 PM Richard (Rick) Karlquist <
> richard at karlquist.com> wrote:
> 
>> General response, not specific to the Waller Flag:
>> 
>> For a number of good reasons, you should not expect
>> a NF below 3 dB for any practical preamp.  OTOH,
>> virtually all radios have an internal switchable preamp.
>> Let's say your radio is really pedestrian, and the
>> internal preamp has 10 dB NF.  Neglecting feedline
>> loss, your preamp gain only needs to be about 13 dB in
>> order to the preamp noise to dominate over the radio
>> noise.  Any additional gain above that will not help
>> you "start to hear band noise" but will instead hear
>> preamp noise.  Some ops like to use additional gain in
>> the preamp to make the AGC threshold occur at a lower
>> level.  This reduces listener fatigue, but does not
>> actually produce any newly-readable signals.
>> 
>> If the above isn't correct, can someone give a worked
>> example of where a 40 dB preamp would make sense?
>> 
>> FWIW, I tried a Waller loop last year in the 160 meter
>> contest.  It was quite large (I have plenty of space).
>> It seemed to be working OK in terms of being directional,
>> but it almost never improved the readability of any
>> signals vs the vertical.  IOW, aiming it at Japan didn't
>> help work JA's, except to the extent that it reduced
>> stateside QRM.  On a clear frequency, there was no advantage.
>> 
>> 73
>> Rick N6RK
>> 
>>> On 12/15/2018 11:15 AM, Stan Stockton wrote:
>>> I am curious to know if anyone on here has scaled a Waller Flag to a
>>> smaller antenna and had any success with whatever might be available for
>>> preamps to bring the gain up enough to start to hear band noise.
>>> 
>>> At my location on Cayman Brac I could probably get by with a 20 foot boom
>>> but not much larger.  According to my model, one with a 50 foot boom is
>>> about -48 dB, one with a 30 foot boom is about -65 dB and one with a 20
>>> foot boom, like I would lilke to put up, is about -79 dB.
>>> 
>>> I guess a lot to do with how successful the antenna might work for me
>> will
>>> have to do with how much preamplifier gain I will need at my particular
>>> location to start to hear noise.  I wanna use it on 160, 80 and 40 and
>> the
>>> gain of the 20 foot boom one is enough for 80 and 40 using a 30 or 40 dB
>>> preamp.
>>> 
>>> Any help would be appreciated.
>>> 
>>> 73 and Merry Christmas...Stan, K5GO/ZF9CW
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>> Reflector
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>>> 
>> 
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