Re: [IRCA] [NRC-AM] Building a "state of the art" MW DX station
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Re: [IRCA] [NRC-AM] Building a "state of the art" MW DX station



Les, unless the feed-line is really long, I'd start with one choke (the RF-CC1 is a good one) and place it close to the receive side. Let the transformer in the base of the antenna act as a Balun on the other end.

One thing we haven't discussed is the absolute importance of a solid ground. This is NOT the building ground; ideally it's separate 8ft ground rods; one at the base of the antenna and one at the receiver. If you can only place ONE rod, run separate ground wires from the ant and from the receiver.

I believe there is a scheduler that works with the Perseus, but I haven't tried it. The current Perseus records an RF bandwidth of 1.6 mHz ! You WILL need a computer that's at least dual-core or faster.

I'm sure you'd have no trouble moving the IQ...it has a lot of smarts in a small package.

Regards,

Mark Durenberger

--------------------------------------------------
From: "Les Rayburn" <les@xxxxxxxxxxxxxxxx>
Sent: Monday, January 02, 2012 9:33 PM
To: <irca@xxxxxxxxxxxxxxxx>
Subject: Re: [IRCA] [NRC-AM]  Building a "state of the art" MW DX station

Understood. I'm thinking of investing in some DX Engineering "Receive Feedline Current Chokes" DXE-RFCC-1 which retail for $64.95 each. I'm hoping this will eliminate any common-mode noise along the feedline. Plan is to place one near the antenna, and another near the receiver.

Any other accessories that I might find useful?

Assuming that I invest in a Perseus SDR receiver, is it possible to "schedule" the radio to record the raw I/O data for most of the MW band overnight? Ideally, I'd like to record about 2 minutes before and after each TOH to catch the maximum number of ID's.

Does the SDR-IQ that I'm currently using have any real value? I know it records only 180 Khz of data, and it's dynamic range is limited compared to both the Perseus and the new WinRadio.

Thanks for the advice. Please keep it coming!

73,

Les Rayburn, N1LF


Les Rayburn, Director
High Noon Film
130 1st Avenue West
Alabaster, AL 35007-8536
(205) 621-7500
(205) 621-7505 FAX
(205) 253-4867 CELL
http://www.highnoonfilm.com


On 1/2/2012 8:11 PM, Mark Durenberger wrote:
Russ is a very smart fellow and well-experienced. To add to his thoughts, noise is not ALL vertically-polarized. Ground-wave noise seems to be...but most other noise seems to be randomly-polarized.

Another source of noise that can't be ignored is noise induced along the lead-in. That noise usually starts at the receive end and makes its back back toward the antenna. Unless that noise is controlled, it might be hard to make the case for one polarity over another. The one thing a vertical has going for it is that it's approximately non-directional.

Regards,

Mark Durenberger

--------------------------------------------------
From: "Russ Edmunds" <wb2bjh@xxxxxxxxx>
Sent: Monday, January 02, 2012 7:24 PM
To: <am@xxxxxxxxxxx>
Cc: "Mailing list for the International Radio Club of America" <irca@xxxxxxxxxxxxxxxx>
Subject: Re: [IRCA] [NRC-AM]  Building a "state of the art" MW DX station


Les, you may want to consider a "stealth" antenna of another sort - a flag.

It can be mounted in a rectangular array on an outer wall or an interior wall or between trees if they're situated properly. Since the wire used can be fairly small, it hides well.

That also requires a matching transformer. Details can be found amongst some of Conelly's articles or Bruce Conti's.

I'm just not sold on a vertical in a high noise location. Most man-made electrical noise is vertically polarized, and the use of a vertical frequently increases the signal/noise ratio.


Russ Edmunds
15 mi NNW of Philadelphia
Grid FN20id
<wb2bjh@xxxxxxxxx>
FM: Yamaha T-80 & Onkyo T-450RDS w/ APS9B @15'; Grundig G8
AM:  Modified Sony ICF 2010's barefoot


--- On Mon, 1/2/12, Mark Durenberger <Mark4@xxxxxxxxxxxxxxx> wrote:

From: Mark Durenberger <Mark4@xxxxxxxxxxxxxxx>
Subject: Re: [NRC-AM] [IRCA] Building a "state of the art" MW DX station
To: am@xxxxxxxxxxx
Cc: "Mailing list for the International Radio Club of America" <irca@xxxxxxxxxxxxxxxx>
Date: Monday, January 2, 2012, 8:19 PM
About 4:1 ratio should work.
Most folks like to roll their own but you can
also try:

http://www.minicircuits.com/products/Transformers.shtml

Should work if you're not near any high RF fields

Regards,

Mark Durenberger

--------------------------------------------------
From: "Les Rayburn" <les@xxxxxxxxxxxxxxxx>
Sent: Monday, January 02, 2012 6:39 PM
To: "Mark Durenberger" <Mark4@xxxxxxxxxxxxxxx>
Cc: "DX @NRC" <am@xxxxxxxxxxx>;
"Mailing list for the International Radio
Club of America" <irca@xxxxxxxxxxxxxxxx>
Subject: Re: [NRC-AM] [IRCA] Building a "state of the art"
MW DX station

> Mark,
>
> Excellent points regarding the change in "mindset"
when using a SDR
> receiver. Hadn't really thought it about it that way.
>
> I might be able to erect a "fold over" vertical
antenna that I could
> deploy only during listening sessions. Assuming
something like 30 feet
> in length, what would I need for a matching
transformer?
>
>
> Les Rayburn, Director
> High Noon Film
> 130 1st Avenue West
> Alabaster, AL 35007-8536
> (205) 621-7500
> (205) 621-7505 FAX
> (205) 253-4867 CELL
> http://www.highnoonfilm.com
>
>
> On 1/2/2012 6:23 PM, Mark Durenberger wrote:
>> Hi Les...good for you!
>>
>> As a general comment addressing two of your
questions:  The "real" SDR
>> is a tool you'll fall in love with.
However...you'll have to make
>> somewhat of a tradeoff from the original way of
thinking.  We've all
>> used loops to pinpoint and tune a specific
frequency.  That's sort of
>> counter-productive when you're using an SDR to
capture the entire band
>> because you usually don't want to favor a unique
channel.
>>
>> So if you're doing wideband with SDR you're
probably going to want to
>> do a Beverage or a vertical.  Sounds like a
Beverage is out for you.
>> I've had tremendous luck with a 30-foot vertical
and a Perseus SDR.
>> No amplification needed; just a matching
transformer.
>>
>> It also sounds like you expect a lot of local
noise.  So you'll
>> probably want to look at a real noise-cancelling
antenna.
>>
>> Google Dallas Lankford's vertical antennas and
some of Mark Connelly's
>> work.
>>
>> Regards,
>>
>> Mark Durenberger
>>
>>
--------------------------------------------------
>> From: "Les Rayburn" <les@xxxxxxxxxxxxxxxx>
>> Sent: Monday, January 02, 2012 6:02 PM
>> To: <am@xxxxxxxxxxx>;
<irca@xxxxxxxxxxxxxxxx>;
<Tvfmdx@xxxxxxxxxxxxxxxx>
>> Subject: [IRCA] Building a "state of the art" MW
DX station
>>
>>> iAfter an absence from medium wave dxing due
to a move to a new
>>> deed-restricted QTH, I find myself itching to
get serious again.
>>> While my present home is far from idea (HOA,
and high local noise
>>> levels), I'm determined to make the best of
it.
>>>
>>> Presently, I have the following equipment
available for us:
>>>
>>> Icom 746 Pro transceiver
>>> RF Space SDR-IQ receiver
>>> Wellbrook AL-1530 Loop antenna
>>> Radio Plus Quantum Phaser
>>> LF Engineering M-601C Active Whip antenna
>>> LF Engineering H-800 Active Whip antenna
>>> LF Engineering N-300 Group loop isolator
>>>
>>> My questions are numerous, but here are the
general ones:
>>>
>>> 1.) To build a state of the art system, would
you recommend
>>> up-grading the SDR-IQ to the Perseus or new
WinRadio SDR?
>>>
>>> 2.) Are there active whip antennas that
perform better than the LF
>>> Engineering models? (I have mounted these to
my roof vents, painted
>>> them black--and so far, no complaints from the
neighbors.
>>>
>>> 3.) I have a undeveloped drainage ditch next
to my home that offers
>>> the possibility of a beverage on the ground
antenna that would run
>>> N/S for 500-800 feet. What couplers would you
recommend for this use?
>>>
>>> 4.) Anyone tried the LF Engineering M-607
Active Loop antenna? Pricey
>>> at $390 but perhaps worth it?
>>>
>>> 5.) Any other station accessories that would
improve things for me?
>>>
>>> Primary interest is in domestic MW DXing,
though I don't mind logging
>>> TA signals when they "in" (rare here). Love to
DX stations in the
>>> Western part of the country most of all.
>>>
>>> Thanks for the advice, and 73,
>>>
>>> Les Rayburn, N1LF
>>> Alabaster, AL (Near Birmingham)
>>>
>>>
>>>
>>>
>>>
>>> -- >>> Les Rayburn, Director
>>> High Noon Film
>>> 130 1st Avenue West
>>> Alabaster, AL 35007-8536
>>> (205) 621-7500
>>> (205) 621-7505 FAX
>>> (205) 253-4867 CELL
>>> http://www.highnoonfilm.com
>>>
>>>
_______________________________________________
>>> IRCA mailing list
>>> IRCA@xxxxxxxxxxxxxxxx
>>> http://montreal.kotalampi.com/mailman/listinfo/irca
>>>
>>> Opinions expressed in messages on this mailing
list are those of the
>>> original contributors and do not necessarily
reflect the opinion of
>>> the IRCA, its editors, publishing staff, or
officers
>>>
>>> For more information: http://www.ircaonline.org
>>>
>>> To Post a message: irca@xxxxxxxxxxxxxxxx
>>>
>>>
>>
>>
> _______________________________________________
> The NRC AM mailing list
> Now accepting pre-orders for the 32nd AM Radio Log
> Questions? owner@xxxxxxxxxxx
> Latest DX Tests are found at
> http://www.nrcdxas.org
>

_______________________________________________
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