Large Backyard MW Antennas


Todd
 

While reading through all the ULR reports of weak AM carrier reception from Korea, Japan, New Zealand, Australia, Polynesia, etc, it makes sense for certain DXers to use a larger signal pickup system for early warning detection. Before venturing outside with PVC and/or FSL antennas for use with ULR portables, a large backyard antenna system such as a flag, sloper, EWE, or low noise random wire antenna would usually detect weak carriers either audibly or visually long before detection on ULR systems. A large higher gain backyard antenna system would first be checked before venturing outside to confront good or otherwise weather conditions. FFT spectrum analysers are capable of sub-audible carrier detection long before the carrier can be audibly heard. When an accurate up to date carrier list to XXX.XXX KHz accuracy, i.e. within 1 Hz, carriers such as 702 KHz ABC Sydney can often be discriminated from Asians or Europeans on the same 9 KHz channel. With this in mind, a 1 Hz precision frequency carrier list is being currently compiled for all MW receivable at my location.
 
The most efficient MW antennas generally be need to be relatively physically large, and mounted outside well away from the house RFI noise field. Based on 160 metre (1.8 MHz) ham radio reception results, a rotatable large horizontal flag mounted on a high tower is likely the ultimate compromise for a backyard MW DX antenna. But a more practical antenna might be one or more fixed vertical flag antennas. A DXer near the west U.S. coast might consider installing a large outdoor flag antenna beaming towards Japan/Korea/China.

The strong signal handling performance with a Drake R8 / R8A / R8B is usually sufficiently high for high gain signal input across the complete MW band, with no resulting internally generated spurious signal images from local stations. All ULRs would suffer from desensitisation and/or image/IMD when connected to high gain wideband antennas in suburban metro high signal areas.
 
Perhaps some on this list might share positives and negatives with various types of outdoor MW antennas. While a Drake R8B, low noise RF preamplifier, and horizontal high elevation flag will often greatly excel ULR portable systems, they are nevertheless useful for early warning signal detection before MW signal propagation peaks to certain areas. It is often only during around the peak of an opening that signals are just barely strong enough for detection on a small ULR system
 
Regards,
 
Todd

Sydney, AU



Gary DeBock
 

Hi Todd,

<<<   Perhaps some on this list might share positives and negatives with various types of outdoor MW antennas. While a Drake R8B, low noise RF preamplifier, and horizontal high elevation flag will often greatly excel ULR portable systems, they are nevertheless useful for early warning signal detection before MW signal propagation peaks to certain areas. It is often only during around the peak of an opening that signals are just barely strong enough for detection on a small ULR system.   >>>

During major ocean cliff DXpeditions the combination of a 30-inch MW loopstick Sony ICF-2010 SSB spotting receiver (photo attached, and also posted at http://www.mediafire.com/view/6ct6za912sd2fu9/Hot-Rod-Paradise-02.jpg  ) and the larger FSL antennas (15 inch and 17 inch) can usually detect the very weakest of transoceanic carrier signals, especially after the mega-FSL's provide their large inductive coupling boost to the modified Sony portable. Of course, whether or not this combination can dig out audio from such weak carriers is another matter entirely, and the Sony portable cannot measure the transmitted frequencies with the accuracy of a table receiver. The combination described above was used to detect a fairly good carrier on 1701 kHz during the July 2012 Cape Perpetua (Oregon) DXpedition, resulting in an English language recording (on a modified PL-380) that Australian DXers said was probably the Voice of Charity.

SSB reception is a huge advantage in detecting extremely weak MW signals, and SSB spotting receivers have been used with ULR's since the very beginning of the Ultralight radio boom in late 2007. The modified SSB spotting receivers (with enhanced MW loopsticks) are critical to ULR DXpedition success at the ocean cliff sites, and provide an ongoing assessment of changing propagation, transoceanic targets and unusual opportunities. Even at home sites the SSB spotting receivers can immediately assess whether transoceanic propagation is worth your DXing effort, or whether the band is in the clunker mode.

73, Gary DeBock (in Puyallup, WA, USA)   

   


-----Original Message-----
From: toddemslie@... [ultralightdx]
To: ultralightdx Sent: Tue, Jan 17, 2017 4:24 pm
Subject: [ultralightdx] Large Backyard MW Antennas

 
While reading through all the ULR reports of weak AM carrier reception from Korea, Japan, New Zealand, Australia, Polynesia, etc, it makes sense for certain DXers to use a larger signal pickup system for early warning detection. Before venturing outside with PVC and/or FSL antennas for use with ULR portables, a large backyard antenna system such as a flag, sloper, EWE, or low noise random wire antenna would usually detect weak carriers either audibly or visually long before detection on ULR systems. A large higher gain backyard antenna system would first be checked before venturing outside to confront good or otherwise weather conditions. FFT spectrum analysers are capable of sub-audible carrier detection long before the carrier can be audibly heard. When an accurate up to date carrier list to XXX.XXX KHz accuracy, i.e. within 1 Hz, carriers such as 702 KHz ABC Sydney can often be discriminated from Asians or Europeans on the same 9 KHz channel. With this in mind, a 1 Hz precision frequency carrier list is being currently compiled for all MW receivable at my location.
 
The most efficient MW antennas generally be need to be relatively physically large, and mounted outside well away from the house RFI noise field. Based on 160 metre (1.8 MHz) ham radio reception results, a rotatable large horizontal flag mounted on a high tower is likely the ultimate compromise for a backyard MW DX antenna. But a more practical antenna might be one or more fixed vertical flag antennas. A DXer near the west U.S. coast might consider installing a large outdoor flag antenna beaming towards Japan/Korea/China.

The strong signal handling performance with a Drake R8 / R8A / R8B is usually sufficiently high for high gain signal input across the complete MW band, with no resulting internally generated spurious signal images from local stations. All ULRs would suffer from desensitisation and/or image/IMD when connected to high gain wideband antennas in suburban metro high signal areas.
 
Perhaps some on this list might share positives and negatives with various types of outdoor MW antennas. While a Drake R8B, low noise RF preamplifier, and horizontal high elevation flag will often greatly excel ULR portable systems, they are nevertheless useful for early warning signal detection before MW signal propagation peaks to certain areas. It is often only during around the peak of an opening that signals are just barely strong enough for detection on a small ULR system
 
Regards,
 
Todd
Sydney, AU


Alex P
 

Todd,

I suppose that what you are asking (or proposing?)  is whether a home QTH with large high performance antenna(s) and otherwise outstanding RX performance should be used as a early warning system as a precursor for running down to the beach with smaller antenna(s) and poor performance portable receivers??

My thoughts are  that I would prefer to be at my home QTH drinking my wine and eating warm quiche in my easy chair rather than crouching on a cold and wet bench at the beach with the wind blowing sand in my bologna sandwich.

Let me know if I've misinterpreted your post.
Alex


Russ Edmunds
 

But one could always go to a beachfront motel, rent a room, and put up antennas on the beach, run cable in and DX in comfort.

Russ Edmunds
15 mi NW Phila
Grid FN20id
<wb2bjh@...>

AM: Modified Sony ICF2010's (4) barefoot w/whip
FM: Yamaha T-80 & T-85, each w/ Conrad RDS Decoder;
Onkyo T-450RDS; Tecsun PL-310 ( 4);
modified Sony ICF2010's (3) w/APS9B @ 15';
modified Sony ICF2010 w/whip


On Thu, Jan 19, 2017 at 10:59 AM, winston376@... [ultralightdx] <ultralightdx@...> wrote:
 

Todd,


I suppose that what you are asking (or proposing?)  is whether a home QTH with large high performance antenna(s) and otherwise outstanding RX performance should be used as a early warning system as a precursor for running down to the beach with smaller antenna(s) and poor performance portable receivers??

My thoughts are  that I would prefer to be at my home QTH drinking my wine and eating warm quiche in my easy chair rather than crouching on a cold and wet bench at the beach with the wind blowing sand in my bologna sandwich.

Let me know if I've misinterpreted your post.
Alex



Todd
 

<I suppose that what you are asking (or proposing) is whether a home QTH with large high performance antenna(s) and otherwise outstanding RX performance should be used as a early warning system as a precursor for running down to the beach with smaller antenna(s) and poor performance portable receivers?>
 
Correct Alex, all of the above is valid.
 
At my home, a 120 ft wire backyard antenna + Icom R8500 is first checked to see if trans-Pacific AM carriers are in from Hawaii, USA, or Mexico. Assuming the carriers are either very weak or not present, it is not worthwhile switching on the Tecsun ULR + 40" PVC loop. During some evenings around 2000 LT, the TP carriers are above average in strength. This indicates it is worthwhile operating the ULR + loop outdoors, and monitoring 1380, 1500, 1570, 1580 KHz TP channels. This is a basic yes/no filter system for proceeding to the next level.
 
A more ideal setup is a relatively large backyard flag antenna fixed towards the USA. Higher gain antennas often produce lower noise levels by virtue of the directional beamwidth attenuating noise from noise outside the antennas main front forward lobe. Increased weak S/N translates to a longer DX window period. A Drake series communications receiver and backyard low noise flag antenna should outperform a small size FSL or loop + ULR, all other factors approximately equal. Given that it is more convenient and cheaper to DX from home, for those with available land space, some effort should be used to investigate higher relative gain receiving systems for use in conjunction with smaller size and gain ULR systems.
 
There are situations where a ULR + FSL or small loop will outperform a large receiving system back home. One example is New Zealand MW signals levels into eastern Australia. NZ MW is considerably stronger on ULR portable systems when operation is on or near a listening site facing the Pacific Ocean. My home location is some 15 miles inland from the coast, hence New Zealand, and TP signals are highly reduced in signal strength, mainly due to terrain blockage.
 
Assuming I was DXing from home on the west coast USA, weak carrier reception would be first checked on a communications receiver before venturing outside to turn on a ULR + loop / FSL at ~ 0600 LT early morning.
 
Gary might share his experiences with the relative performance of FSL and small loops versus larger antennas such as flags and beverages at more optimal coastal listening sites. Some interesting pictures have been posted of smaller portable flag antennas used at coastal DX monitoring sites. The recent Japanese / USA west coast DXpedition is one example. When different types of antennas are used on DXpeditions at the same listening site, the reception results and relative strengths indicate receiving system efficiency. Man-made noise interference is often lower at coastal listening sites compared to a home suburban backyard system. Line of sight to the horizon is desirable for all DX from LW to SHF, hence why coastal listening sites provide such impressive TP DX results when suitable signal propagation is open.
 
Regards,
 
Todd


Gary DeBock
 

Thanks for your observations and comments, Todd.

<<<   Gary might share his experiences with the relative performance of FSL and small loops versus larger antennas such as flags and beverages at more optimal coastal listening sites. Some interesting pictures have been posted of smaller portable flag antennas used at coastal DX monitoring sites. The recent Japanese / USA west coast DXpedition is one example. When different types of antennas are used on DXpeditions at the same listening site, the reception results and relative strengths indicate receiving system efficiency. Man-made noise interference is often lower at coastal listening sites compared to a home suburban backyard system. Line of sight to the horizon is desirable for all DX from LW to SHF, hence why coastal listening sites provide such impressive TP DX results when suitable signal propagation is open.   >>>

During major ocean cliff DXpeditions there are usually multiple antenna and receiver combinations deployed, and of course there is a pretty long track record of the performance of the Ultralight + FSL combos against the Perseus-SDR + small broadband loop combos. The first major comparison of these was during the record-breaking July 2014 Rockwork 4 DXpedition, during which far more New Zealand stations were received (88 total) than ever before here on the North American west coast.

Because of the spectrum-capture capability Chuck's Perseus-SDR +15' x 15' broadband loop (assisted by an 11 dB preamp) received the vast majority of stations (87), but he admitted that the Tecsun PL-380 + 15" FSL combination could usually provide better signal quality on the lower MW frequency Kiwi stations. One weak (and rare) Kiwi station was received only on the ULR + FSL combination-- 585-Radio Ngati Porou. The single-optimized-frequency advantage of the tuned, High-Q FSL antennas makes them pretty tough competitors on the lower MW frequencies, signal-for-signal. Of course they can only tune one frequency at a time, though, so the total DX number of DX stations that they can receive is always much fewer than the small broadband loops can receive. One other related factor is that the $50 ULR's are nowhere near as sensitive and selective as the Perseus-SDR's, so the fact that the FSL antennas can make such a combo very competitive on the lower MW frequencies is a pretty astonishing fact. Once the FSL antennas are adapted for use with the Perseus-SDR and other communication receivers, such a combo would probably become the new "King of the Hill" on ocean cliffs, frequency-for-frequency.

73, Gary DeBock (in Puyallup, WA, USA)

     


-----Original Message-----
From: toddemslie@... [ultralightdx]
To: ultralightdx <ultralightdx@...>
Sent: Thu, Jan 19, 2017 6:08 pm
Subject: Re: [ultralightdx] Large Backyard MW Antennas

 
 
Correct Alex, all of the above is valid.
 
At my home, a 120 ft wire backyard antenna + Icom R8500 is first checked to see if trans-Pacific AM carriers are in from Hawaii, USA, or Mexico. Assuming the carriers are either very weak or not present, it is not worthwhile switching on the Tecsun ULR + 40" PVC loop. During some evenings around 2000 LT, the TP carriers are above average in strength. This indicates it is worthwhile operating the ULR + loop outdoors, and monitoring 1380, 1500, 1570, 1580 KHz TP channels. This is a basic yes/no filter system for proceeding to the next level.
 
A more ideal setup is a relatively large backyard flag antenna fixed towards the USA. Higher gain antennas often produce lower noise levels by virtue of the directional beamwidth attenuating noise from noise outside the antennas main front forward lobe. Increased weak S/N translates to a longer DX window period. A Drake series communications receiver and backyard low noise flag antenna should outperform a small size FSL or loop + ULR, all other factors approximately equal. Given that it is more convenient and cheaper to DX from home, for those with available land space, some effort should be used to investigate higher relative gain receiving systems for use in conjunction with smaller size and gain ULR systems.
 
There are situations where a ULR + FSL or small loop will outperform a large receiving system back home. One example is New Zealand MW signals levels into eastern Australia. NZ MW is considerably stronger on ULR portable systems when operation is on or near a listening site facing the Pacific Ocean. My home location is some 15 miles inland from the coast, hence New Zealand, and TP signals are highly reduced in signal strength, mainly due to terrain blockage.
 
Assuming I was DXing from home on the west coast USA, weak carrier reception would be first checked on a communications receiver before venturing outside to turn on a ULR + loop / FSL at ~ 0600 LT early morning.
 
Gary might share his experiences with the relative performance of FSL and small loops versus larger antennas such as flags and beverages at more optimal coastal listening sites. Some interesting pictures have been posted of smaller portable flag antennas used at coastal DX monitoring sites. The recent Japanese / USA west coast DXpedition is one example. When different types of antennas are used on DXpeditions at the same listening site, the reception results and relative strengths indicate receiving system efficiency. Man-made noise interference is often lower at coastal listening sites compared to a home suburban backyard system. Line of sight to the horizon is desirable for all DX from LW to SHF, hence why coastal listening sites provide such impressive TP DX results when suitable signal propagation is open.
 
Regards,
 
Todd