Re: Topband: Sanity Check on K9AY Loop Sensitivity

[Joel Gray]

I was able to find the specs on the Array Solutions control box.  Yes there
is a bandpass filter when the preamp is switched on .
This is copied from the documentation:
Preamplifier: 15 dB gain, feedback type, using a silicon NPN transistor
Filter passband: ±2 dB from 1.80 to 4.5 MHz
Filter stopband: –55 dB at 7 MHz, –50 dB below 1450 kHz (typical)

I'm not sure if this is the control box you are using, but thought it may
be helpful.

73, Joel
N9LQ



On Mon, Dec 12, 2022 at 9:29 AM Joel Gray  wrote:

> Hi Pete,
> If you are using the blue Array Solutions control box, it is my
> recollection that when you switch on the preamp, it also adds a BCB filter
> to the signal path.
> 73, Joel
> N9LQ
>
>
> On Mon, Dec 12, 2022 at 9:11 AM Frank W3LPL 
> wrote:
>
>> Hi Pete,
>>
>> Any preamp that has loss definitely needs repair.  Preamps are simple
>> devices that are easy to troubleshoot, the transistor is a likely
>> culprit
>>
>> 73
>> Frank
>> W3LPL
>>
>> - Original Message -
>> From: "Pete N4ZR N4ZR" 
>> To: "topband" 
>> Sent: Monday, December 12, 2022 2:59:09 PM
>> Subject: Topband: Sanity Check on K9AY Loop Sensitivity
>>
>> I just deployed my K9AY loop (yes, I know I'm late).  Anyhow, while it
>> shows substantial directivity on broadcast stations, I was surprise by
>> how much the K9AY loop's sensitivity suffers compared to my inverted L.
>> Listening to a broadcast station with the K9AY on 1500 KHz, the station
>> is S6-7 in the right direction and S3 in the reverse. and S9 +10 on the
>> inverted L. There's also something haywire in the K9AY's preamp, which
>> *reduces* signal by a couple of S-Units.  Could be I need to replace the
>> transistor?
>>
>> --
>> 73, Pete N4ZR
>> One of the RBN team
>> _
>> Searchable Archives: http://www.contesting.com/_topband - Topband
>> Reflector
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>> Searchable Archives: http://www.contesting.com/_topband - Topband
>> Reflector
>>
>
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Re: Topband: Sanity Check on K9AY Loop Sensitivity

[Joel Gray]

Hi Pete,
If you are using the blue Array Solutions control box, it is my
recollection that when you switch on the preamp, it also adds a BCB filter
to the signal path.
73, Joel
N9LQ


On Mon, Dec 12, 2022 at 9:11 AM Frank W3LPL  wrote:

> Hi Pete,
>
> Any preamp that has loss definitely needs repair.  Preamps are simple
> devices that are easy to troubleshoot, the transistor is a likely
> culprit
>
> 73
> Frank
> W3LPL
>
> - Original Message -
> From: "Pete N4ZR N4ZR" 
> To: "topband" 
> Sent: Monday, December 12, 2022 2:59:09 PM
> Subject: Topband: Sanity Check on K9AY Loop Sensitivity
>
> I just deployed my K9AY loop (yes, I know I'm late).  Anyhow, while it
> shows substantial directivity on broadcast stations, I was surprise by
> how much the K9AY loop's sensitivity suffers compared to my inverted L.
> Listening to a broadcast station with the K9AY on 1500 KHz, the station
> is S6-7 in the right direction and S3 in the reverse. and S9 +10 on the
> inverted L. There's also something haywire in the K9AY's preamp, which
> *reduces* signal by a couple of S-Units.  Could be I need to replace the
> transistor?
>
> --
> 73, Pete N4ZR
> One of the RBN team
> _
> Searchable Archives: http://www.contesting.com/_topband - Topband
> Reflector
> _
> Searchable Archives: http://www.contesting.com/_topband - Topband
> Reflector
>
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Re: Topband: ZK3A

[Joel Gray]

Yes, I worked them at 0600Z on FT8, and it is not yet appearing.  Hopefully
the next log update will have them in there.
73, Joel  - N9LQ


On Tue, Oct 8, 2019 at 1:22 PM ShelbyK4WW  wrote:

> Anyone else work ZK3A today about 0610Z, and the contact not appearing in
> their online log search? Online log search indicates last QSO is database:
> 08/10/2019 1103Z
> Thanks
>
> 73, Shelby - K4WW
> As I don't have an iPad nor iPhone, sent from my PC
> _
> Searchable Archives: http://www.contesting.com/_topband - Topband
> Reflector
>
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Re: Topband: K9AY loop -- adding additional radials?

[Joel Gray]

Pete,   I added 4 radials and a 4' ground rod like you did.  I am not sure
if adding more will help, but I am pretty sure it could not hurt, so it
might be an easy test.  Another thing I did which seemed to help was to cut
the trace as described in the documentation to isolate the feedline shield
from the ground of the antenna.  I also put a feedline choke on the coax
near the antenna to try and make sure the feedline was not picking up
signals and disrupting the pattern.  My choke was 6 turns through 5 stacked
#31 cores.  I am quite happy with the performance of it.  Good luck!

On Tue, Nov 13, 2018 at 4:34 PM Peter Bertini 
wrote:

> Hello to the group.  I installed a K9AY system last week and added four 21
> foot radials on ground radials with a ground rod at the center.  The
> antenna didn't seem to have much directivity, so today I added another four
> 4-ft inexpensive TV type ground rods at the ends of each of the radials.
> We've had some heavy rain, but tonight I am noticing excellent nulls on
> European stations when changing directions.  The antenna is located in a
> wooded area, and I had assumed the ground was fairly conductive, but
> apparently not... would adding another set of four radials in between the
> existing four improve the system?  I am not sure how much the change
> relates to the heavy rains or adding the grounds.
>
> Pete
> _
> Searchable Archives: http://www.contesting.com/_topband - Topband
> Reflector
>
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Re: Topband: Which compromise receiving antenna

[Joel Gray]

For the last two seasons, I had two 225' BOGs put out; one pointing NE, and
one pointing SE.  They worked well.  I also have a K9AY, and in general, I
like the K9AY performance better than the BOGs.  And it provides 4
directions in a small footprint.  Mine hangs from a tree branch.  I found
that occasionally one of the BOGs would work a bit better than the K9AY,
but not very often.  I am debating whether to even put the BOGs out this
year.  That being said, BOGs can work well, are pretty simple to do, and
fairly inexpensive.  I have not tried the reversible kind so can't comment
on that part.  73.

On Tue, Nov 6, 2018 at 9:40 AM N4ZR  wrote:

> I've just spent a very educational hour with Google Earth looking at my
> Beverage options for 160M.  On a 45/225 azimuth I can only get about 215
> feet.  Is that even worth doing with a conventional Beverage? What about
> a BOG?  Because of my lot layout I will need to use a reversible 2-wire
> Beverage with the NE end right outside my shack.  Don't know if the
> KD9SV reversing transformers will work for a BOG.
>
> My other reasonable receiving option is a K9AY loop or similar.
> Transmitting antenna will be an inverted L, with vertical section
> probably no more than 60 feet. I'd like to finish my 160M DXCC this
> winter if possible
>
> --
>
> 73, Pete N4ZR
> Check out the Reverse Beacon Network
> at , now
> spotting RTTY activity worldwide.
> For spots, please use your favorite
> "retail" DX cluster.
>
> _
> Searchable Archives: http://www.contesting.com/_topband - Topband
> Reflector
>
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Re: Topband: Multiple verticals one feed-point.

[Joel Gray]

Gary,
I am not sure about all bands, but I have done it with 3 bands.  I run my
160 inverted L, a vertical for 80 and a vertical for 40 all off of the same
feedline and ground radial system.  At least for these three bands, they
don't have a lot of interaction.  My 4NEC2 model showed this, and my
experience as I added each additional antenna wire required minimal or no
adjustment of the previous elements.  My wires are spaced about 12" apart.
73, Joel
N9LQ




On Wed, Sep 19, 2018 at 3:35 PM Gary Smith  wrote:

> My HF antennas are all wire verticals; 20M
> vertical, 30M vertical, 40M vertical, 80
> INV-V & 160 sloper. Using the Ameritron
> remote coax switch it allows me to select
> one of these antennas and this allows a
> match to everything from 160-6 except for
> 60 meters which I don't use anyway. All
> are connected to the radial plate which
> has maybe 40 or so 130' long radials. I
> use the 160 sloper for 160, 12, 10 & 6M (I
> now have a 7 el yagi for 6M)
>
> This latest thread has me wondering about
> what would be likely to happen if I didn't
> use the coax switch and instead ran all
> the wires off a common feed-point? The
> only think I can think of that jumps out
> at me is the possibility of harmonics.
>
> Perhaps harmonics are not an issue? I've
> long used a 40M antenna for 15M as well
> with no complaints. I used to use a
> Mor-Gain antenna as a Novice & General and
> it was a multi band dipole which seemed to
> work fairly well, but in the sunspot cycle
> peak back in the late 70's a coat hanger
> would let you work DX.
>
> 73,
>
> Gary
> KA1J
>
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Re: Topband: 160 meter L

[Joel Gray]

> I have a 75-80 1/4 wave vertical.  It has 20 1/4 wavelength radials. I
> would like to run an inverted l up the radiator and horizontal for the
rest
> of the radiator both antennas fed with same feed line. - Doug. WD8Z

I started out with a 1/4w inverted L on 160, about 55' high, the rest
horizontal.  I added an L network at the base for a better match given my
longish feedline.  I later added a 1/4w 80m vertical spaced about 2 feet
away with pvc spacers.  Actually, the last 10-15 feet are bent over like an
inverted L also.  They share the same feedline, and the 80m antenna
connects before the matching network.  I do not use any relays to switch
between them, both are always connected.  The modeling I did (4nec2) showed
that each antenna presented a relatively high impedance on the other band.
I viewed this as similar in principle to a fan dipole.  I do not know
whether the pattern is significantly affected by this or not.  With the 2
foot spacing, I did not have to make any significant adjustments to the 160
inverted L.  I cannot say whether closer spacing would work.  I assume it
would, although there would most likely be more interaction.  I use a good
common mode choke on the feedline (overkill perhaps?).  Both antennas load
up nicely.  Although I can't really measure field strength, I can say that
adding the vertical on 80m increased my country count fairly quickly so it
is working better than my inverted V at 55 feet.  My 160m performance
doesn't seem to be affected at all.  Good luck with it!
73, Joel
N9LQ

On Thu, Mar 23, 2017 at 2:26 PM, Joel Gray  wrote:

> > I have a 75-80 1/4 wave vertical.  It has 20 1/4 wavelength radials. I
> > would like to run an inverted l up the radiator and horizontal for the
> rest
> > of the radiator both antennas fed with same feed line. - Doug. WD8Z
>
> I started out with a 1/4w inverted L on 160, about 55' high, the rest
> horizontal.  I added an L network at the base for a better match given my
> longish feedline.  I later added a 1/4w 80m vertical spaced about 2 feet
> away with pvc spacers.  Actually, the last 10-15 feet are bent over like an
> inverted L also.  They share the same feedline, and the 80m antenna
> connects before the matching network.  I do not use any relays to switch
> between them, both are always connected.  The modeling I did (4nec2) showed
> that each antenna presented a relatively high impedance on the other band.
> I viewed this as similar in principle to a fan dipole.  I do not know
> whether the pattern is significantly affected by this or not.  With the 2
> foot spacing, I did not have to make any significant adjustments to the 160
> inverted L.  I cannot say whether closer spacing would work.  I assume it
> would, although there would most likely be more interaction.  I use a good
> common mode choke on the feedline (overkill perhaps?).  Both antennas load
> up nicely.  Although I can't really measure field strength, I can say that
> adding the vertical on 80m increased my country count fairly quickly so it
> is working better than my inverted V at 55 feet.  My 160m performance
> doesn't seem to be affected at all.  Good luck with it!
> 73, Joel
> N9LQ
>
>
> On Thu, Mar 23, 2017 at 1:29 PM, jon jones  wrote:
>
>> I fly a balloon vertical for 160 meters (1/4 wavelength) with 8 radials.
>>
>> For 80 meters I use a standard tuner right at the base feed point to
>> match it = ~ 1/2 wave. It gets out quite well. Voltages would be
>> high so use appropriately rated coils/capacitors. This may be another
>> option for a two band inverted L if one does not wish to use a trap.
>>
>>  - Jon N0JK
>>
>>
>> > I have a 75-80 1/4 wave vertical.  It has 20 1/4 wavelength radials. I
>> > would like to run an inverted l up the radiator and horizontal for the
>> rest
>> > of the radiator both antennas fed with same feed line. - Doug. WD8Z
>>
>>
>> _
>> Topband Reflector Archives - http://www.contesting.com/_topband
>>
>
>
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