Date   

Re: 1566 KOR HLAZ 12480km before sunset. Barefoot XHDATA D-808

Peter 1956
 

This one is a tad more parochial.
1449 Maldives 6108km Received in local daylight XHDATA D-808 internal ferrite rod.
https://youtu.be/DHPtcRLMD10
Peter


1566 KOR HLAZ 12480km before sunset. Barefoot XHDATA D-808

Peter 1956
 

Outside in a rural garden in Botswana. Guest appearance by some sheep.

It might have a low index but I think it isn't bad DX. ;)
https://youtu.be/1nP4NWOHDOs

Peter


Re: Air Band Receivers

Steve Whitt
 

Airnav.com works fine here in the UK

 

Rgds

Steve

 

From: main@UltralightDX.groups.io [mailto:main@UltralightDX.groups.io] On Behalf Of DX Pedro
Sent: 29 July 2021 15:01
To: main@ultralightdx.groups.io
Subject: Re: [UltralightDX] Air Band Receivers

 

Sadly, US restricted :(

 

// pedro andrade

 

 

On Thu, Jul 22, 2021 at 10:23 PM Joseph Rotman via groups.io <N9JCQ=aol.com@groups.io> wrote:


This is what I use for airport frequencies:https://www.airnav.com/

-----Original Message-----
From: Jock Elliott <jock.elliott@...>
To: main@ultralightdx.groups.io
Sent: Thu, Jul 22, 2021 4:34 am
Subject: Re: [UltralightDX] Air Band Receivers

Radio Reference -- https://www.radioreference.com/apps/db/ -- is an excellent source of frequency information of all sorts, including aviation.

 

I have used it for United States information, and there are pull-downs on the right for other countries, although I don't know how complete or accurate the information is for other countries.


Re: Air Band Receivers

DX Pedro
 

Sadly, US restricted :(

// pedro andrade


On Thu, Jul 22, 2021 at 10:23 PM Joseph Rotman via groups.io <N9JCQ=aol.com@groups.io> wrote:

This is what I use for airport frequencies:https://www.airnav.com/

-----Original Message-----
From: Jock Elliott <jock.elliott@...>
To: main@ultralightdx.groups.io
Sent: Thu, Jul 22, 2021 4:34 am
Subject: Re: [UltralightDX] Air Band Receivers

Radio Reference -- https://www.radioreference.com/apps/db/ -- is an excellent source of frequency information of all sorts, including aviation.

I have used it for United States information, and there are pull-downs on the right for other countries, although I don't know how complete or accurate the information is for other countries.


Re: Ferrite technical considerations for FSL’s

Robert Conboy
 

Interesting! A Varactor tuned ferrite sleeve loop with a preamp, and a rotator for remote operation. I would have thought that the varactors would be too temperature sensitive, and too low Q - but apparently not. I have a 5-500 pF vacuum variable capacitor for use in a future similar project.

I have gone a different direction with the active part, using an amplifier for regenerative feedback to overcome losses in the ferrite. This enables Q to be dialed up high enough to eliminate the audio almost entirely while looking at carriers and their offsets using an SDR. Gain is in the neighborhood of 50 dB while -3dB bandwidth is about 20 Hz just before oscillation.

 It is also useful for cleaning up extremely weak audio with lower Q settings (that are still higher than attainable without feedback, gain in the neighborhood of 35 dB with -3dB bandwidth about 100 Hz. This bandwidth results in audio that is heard at very low level, (turn up the volume) but noise is even lower.  It is not as low bass heavy as one would expect because the speaker in a tiny  portable radio is incapable of reproducing it. 

Ferrite sheets are an interesting proposition, if they can have high enough permeability to overcome their thinness, with low enough losses to attain good selectivity, and large enough for antenna use. Ferrite designed for EMI suppression is deliberately extremely lossy. I have made the assumption sheet ferrites aren’t suitable, but I have been wrong before.



On Jul 29, 2021, at 5:01 AM, valentino barbi <barbivalentino@...> wrote:


Il giorno gio 29 lug 2021 alle ore 10:02 i2NDT Claudio via groups.io <i2ndt=yahoo.it@groups.io> ha scritto:
this could be another way to make a ferrite sleeve:

https://swling.com/blog/2017/07/valentino-experiments-with-a-ferrite-sheet-loop-antenna/

using ferrite sheets which are much more light and cheep than ferrite roads...

https://www.shopnfc.com/it/tag-nfc-schermati/157-115-ferrite-adesiva-per-tag-nfc-schermati.html#/40-formato-foglio_a4

best DX
de
i2NDT Claudio


Re: Ferrite technical considerations for FSL’s

valentino barbi
 

Il giorno gio 29 lug 2021 alle ore 10:02 i2NDT Claudio via groups.io <i2ndt=yahoo.it@groups.io> ha scritto:
this could be another way to make a ferrite sleeve:

https://swling.com/blog/2017/07/valentino-experiments-with-a-ferrite-sheet-loop-antenna/

using ferrite sheets which are much more light and cheep than ferrite roads...

https://www.shopnfc.com/it/tag-nfc-schermati/157-115-ferrite-adesiva-per-tag-nfc-schermati.html#/40-formato-foglio_a4

best DX
de
i2NDT Claudio


Re: Introducing the ULR DXing Chart-Index

Gary DeBock
 

The really astronomical indexes come from low-powered Longwave aeronautical beacons (NDB's) received at ranges over 10,000 km across the equator. 362-WK in Whakatane, New Zealand (25 watts at 11,017 km from Manzanita, Oregon) results in a wacky index of 440.68, while 366-SF in Springfield, New Zealand (50 watts at 10,977 km from Manzanita, Oregon) results in a more modest 219.54.

The best medium wave DX index at the same Rockwork Cliff would be for reception of 558-7BU in Burnie, Tasmania, Australia during the August 2017 DXpedition. That 2,000 watt station was received at 13,128 km from Manzanita, for a very modest index of 6.56.

Gary DeBock (in Puyallup, WA, USA)


Re: Introducing the ULR DXing Chart-Index

Peter 1956
 

The only one I can find with an impressive index, was received outdoors next to a car park, in Blackpool UK, on a barefoot XHDATA D-808 at 06:50 UTC on 31st Oct 2019.
1450 USA WPGG Atlantic City NJ 1kW 5449km index 5.449

Peter


Re: Ferrite technical considerations for FSL’s

i2NDT Claudio
 

this could be another way to make a ferrite sleeve:

https://swling.com/blog/2017/07/valentino-experiments-with-a-ferrite-sheet-loop-antenna/

using ferrite sheets which are much more light and cheep than ferrite roads...

https://www.shopnfc.com/it/tag-nfc-schermati/157-115-ferrite-adesiva-per-tag-nfc-schermati.html#/40-formato-foglio_a4

best DX
de
i2NDT Claudio


Re: Introducing the ULR DXing Chart-Index

Frank Standford
 

Ideally we could adjust these values, based on our local area and needs. 
I did some quick maths on a few examples.
 
550.0 Example 1 643.0 5000.0 0.129
550.0 Example 2 2500.0 5000.0 0.500
660.0 Example 3 321.0 200.0 1.605
660.0 Example 4 50.0 100.0 0.500
660.0 Example 5 1000.0 500.0 2.000
660.0 Example 6 4023.0 5000.0 0.805

 
 
Sent: Thursday, July 29, 2021 at 3:05 PM
From: "Paul Blundell" <tanger32au@...>
To: main@ultralightdx.groups.io
Subject: Re: [UltralightDX] Introducing the ULR DXing Chart-Index
Given we are a world wide group, we will always have differences in the way things work and what might work for one group / area might not work as well in another.
 
On Thu, Jul 29, 2021 at 2:29 PM Peter 1956 <pe1etr@...> wrote:
Exactly Paul, so there is no point me taking part in this, as I don't have any low power stations close to me. My long distance catches get a low index score. so no point entering them. This whole index concept seems flawed to me.

Peter

 

 

 
 
--
Paul
 


Re: Introducing the ULR DXing Chart-Index

Frank Standford
 

While I have not personally added these to my loggings yet, I suspect I will be much the same where the higher power is the limiting factor in getting a good score.

 
 
Sent: Thursday, July 29, 2021 at 2:29 PM
From: "Peter 1956" <pe1etr@...>
To: main@UltralightDX.groups.io
Subject: Re: [UltralightDX] Introducing the ULR DXing Chart-Index
Exactly Paul, so there is no point me taking part in this, as I don't have any low power stations close to me. My long distance catches get a low index score. so no point entering them. This whole index concept seems flawed to me.

Peter


Re: Loggings - 28/07/2021 - Take 2

Frank Standford
 

It looks like 5MV was the best catch? I find it funny to see stations on non 10k spacing.

 
 
Sent: Thursday, July 29, 2021 at 11:54 AM
From: "Paul Blundell" <tanger32au@...>
To: main@UltralightDX.groups.io
Subject: [UltralightDX] Loggings - 28/07/2021 - Take 2
The below were logged last night between 8:15pm and 8:45pm using my Retekess V-115 and 3" FSL at home.
 
-------------------------
**MWDxerDB - Report**
Report Date: 07/29/2021
Report Time: 11:45:17
-------------------------

Freq / Name: 0567 - 4JK
Details: Julia Creek - National -10000w
Notes: 28/07/2021 - ULDXIndex = 0.2358
 
Freq / Name: 0612 - 4QR
Details: Brisbane National 50000
Notes: 28/07/2021 - ULDXIndex = 0.03313 
 
Freq / Name: 0675 - 2CO
Details: Corowa -National - 10000w
Notes: 28/07/2021 - ULDXIndex = 0.0611
 
Freq / Name: 0945 - Bendigo
Details: Bendigo - HPON - 2000w
Notes: 28/07/2021 - ULDXIndex = 0.291 
 
Freq / Name: 0963 - 5SE
Details: Mount Gambier - Commercial - 5000w
Notes: 28/07/2021 - ULDXIndex = 0.1366
 
Freq / Name: 1062 - 5MV
Details: Renmark/Loxton - National - 2000w
Notes: 28/07/2021 -ULDXIndex = 0.4905 
 
Freq / Name: 1170 - 2CH
Details: Sydney - Commercial - 5000w
Notes: 28/07/2021 - ULDXIndex = 0.1822
 
Freq / Name: 1206 - 2CC
Details: Canberra - Commercial - 5000w
Notes: 28/07/2021 - ULDXIndex = 0.1424
 
Freq / Name: 1512 - 2RN
Details: Newcastle - National - 10000w
Notes: 28/07/2021 - ULDXIndex = 0.1039
 


Re: WFNI 1070 Indianapolis (ex WIBC) going off 8/2

kevin asato
 

KFI is at 640KHz in Los Angeles. 1070KHz is KNX with transmitter in Torrance, CA (Los Angeles County).
73,
kevin
kc6pob

On Wed, Jul 28, 2021 at 9:15 PM Dave Hascall <dhinfomedia@...> wrote:
I don't doubt that KFI is underneath WFNI at least a few times a year but DXers in Illinois hear them a time or two a year.  I did manage them once but my odds are increasing for a relog and maybe a new ULR logbook.


Re: Introducing the ULR DXing Chart-Index

Paul Blundell
 

Given we are a world wide group, we will always have differences in the way things work and what might work for one group / area might not work as well in another.


On Thu, Jul 29, 2021 at 2:29 PM Peter 1956 <pe1etr@...> wrote:
Exactly Paul, so there is no point me taking part in this, as I don't have any low power stations close to me. My long distance catches get a low index score. so no point entering them. This whole index concept seems flawed to me.

Peter



--
Paul


Re: Introducing the ULR DXing Chart-Index

Peter 1956
 

Exactly Paul, so there is no point me taking part in this, as I don't have any low power stations close to me. My long distance catches get a low index score. so no point entering them. This whole index concept seems flawed to me.

Peter


Re: WFNI 1070 Indianapolis (ex WIBC) going off 8/2

Dave Hascall
 

I don't doubt that KFI is underneath WFNI at least a few times a year but DXers in Illinois hear them a time or two a year.  I did manage them once but my odds are increasing for a relog and maybe a new ULR logbook.


Loggings - 28/07/2021 - Take 2

Paul Blundell
 

The below were logged last night between 8:15pm and 8:45pm using my Retekess V-115 and 3" FSL at home.
 
-------------------------
**MWDxerDB - Report**
Report Date: 07/29/2021
Report Time: 11:45:17
-------------------------

Freq / Name: 0567 - 4JK
Details: Julia Creek - National -10000w
Notes: 28/07/2021 - ULDXIndex = 0.2358

Freq / Name: 0612 - 4QR
Details: Brisbane National 50000
Notes: 28/07/2021 - ULDXIndex = 0.03313 

Freq / Name: 0675 - 2CO
Details: Corowa -National - 10000w
Notes: 28/07/2021 - ULDXIndex = 0.0611

Freq / Name: 0945 - Bendigo
Details: Bendigo - HPON - 2000w
Notes: 28/07/2021 - ULDXIndex = 0.291 

Freq / Name: 0963 - 5SE
Details: Mount Gambier - Commercial - 5000w
Notes: 28/07/2021 - ULDXIndex = 0.1366

Freq / Name: 1062 - 5MV
Details: Renmark/Loxton - National - 2000w
Notes: 28/07/2021 -ULDXIndex = 0.4905 

Freq / Name: 1170 - 2CH
Details: Sydney - Commercial - 5000w
Notes: 28/07/2021 - ULDXIndex = 0.1822

Freq / Name: 1206 - 2CC
Details: Canberra - Commercial - 5000w
Notes: 28/07/2021 - ULDXIndex = 0.1424

Freq / Name: 1512 - 2RN
Details: Newcastle - National - 10000w
Notes: 28/07/2021 - ULDXIndex = 0.1039
 


Re: Ferrite technical considerations for FSL’s

Frank Standford
 

Interesting but WAY over my poor old head.

 
 
Sent: Thursday, July 29, 2021 at 8:58 AM
From: "Robert Conboy" <robconboy@...>
To: main@UltralightDX.groups.io
Subject: [UltralightDX] Ferrite technical considerations for FSL’s

The effective initial permeability of a ferrite rod decreases with increasing diameter. This is because the flux is increasingly concentrated toward the outside of the radius. As you go deeper toward the center, the presence of ferrite has a diminishing contribution to the flux. Therefore, for large enough diameters, you can use a hollow cylinder of ferrite with little effect on the inductance as compared to solid ferrite. In other words, a ferrite sleeve. I *think*  diameter’s diminishing contribution to total flux begins to become significant with radiuses between 8 and 16 mm.

 

The effective permeability of a 9 inch or 230 mm diameter slug of mix 61 (u’ = 125) is about 4 or 5. In this case, most of the ferrite isn’t actually being used if it is a (heavy) solid slug. The calculations that predict inductance still work fairly accurately for hollow ferrite cylinders of 8 to 16 mm wall thickness.

 

The sensitivity of an air-core loop antenna increases with increasing diameter. This also applies if there is ferrite present.

 

For a fixed length of ferrite, as diameter increases, ferrite’s contribution to sensitivity decreases in proportion to that of an air core loop. (Ferrite permeability is still higher than air, but diminishing) The effective permeability of the ferrite decreases with increasing diameter. At some point in increasing diameter, the presence of ferrite will have a nil effect on the antenna sensitivity.  It becomes an air core loop slightly enhanced by the presence of ferrite. I *think* that diameter is somewhere between 1/2 and 1 meter, (beyond which it behaves mostly as an air core loop). My intuition says that  diameter may be smaller for shorter lengths of ferrite but I have not confirmed this experimentally.

 

The converse of this relationship is that increasing length of the ferrite increases the magnetic flux. At longer lengths, the effective permeability begins to approach a limit set by the initial permeability of the ferrite material. Therefore, the benefit  gained by further increasing the length diminishes as the length increases. 

 

In between these two extremes there is a practical region where doubling the length has about the same effect on antenna sensitivity as doubling the diameter.  

 

For solid ferrite, going for length is far more efficient because increasing the diameter results in an exponential increase of mass.

 

For a hollow sleeve consisting of bars or rods mounted on a former, arranged as a cylinder, doubling the length vs. doubling the diameter use the same amount of ferrite. Antenna performance has about a 1 to 1 ratio between proportional changes in diameter vs. proportional changes in length. Doubling the diameter has about the same effect as doubling the length of ferrite.

 

However, there is one possible advantage of going for length over diameter. Longer ferrite has greater effective permeability. Therefore one may need less Litz wire to attain the same value of inductance. Less wire equals less resistance equals better selectivity and gain. This improvement may be unmeasurable if losses in ferrite are dominant. On the other hand, Litz wire is expensive, so there may still be a cost advantage. It may be also easier to construct a longer ferrite sleeve than a fatter one.

 

I made my first “ferrite sleeve antenna” on the job in 2005 using 24 mix 61 ferrite rods 6 inches long. These rods originally were vendor samples that were candidates for cost reducing a radio. I built the antenna for the purpose of evaluating another radio prototype, and later, experimenting to see if it was possible to improve reception of MW  HD radio. I was using an ibiquity evaluation board. The idea was to overcouple to a tuned resonant antenna to create a two peaked response curve enhancing the two outermost iboc sidebands. The experiment worked beautifully but did not improve HD reception. Then with critical coupling it became a fantastic dx antenna for otherwise mediocre radios. This antenna eventually was donated to a middle school science program.


Re: Introducing the ULR DXing Chart-Index

Frank Standford
 

Hello.
My logs go back way too far and have too little information in places to be able to add this in for them. Anything new, I will be adding it in.

 
 
Sent: Thursday, July 29, 2021 at 7:25 AM
From: "Pedro Porres" <pporres@...>
To: main@UltralightDX.groups.io
Subject: Re: [UltralightDX] Introducing the ULR DXing Chart-Index
Hi all,
Lately I'm a bit busy moving to my new apartment, I still usually read your messages. I just sent Jorge a file with the 5 listeners requested. I realize that in relation to the proposed index, it is more interesting to capture low power stations, although closer, than distant stations but with high transmission power. I hope this activity will serve to encourage new fans of DX and radio.
Best regards to everyone.

Pedro Porres
Cordoba (Spain)


Re: March 2021 South American Ultralight DXpedition by Martin Butera

Frank Standford
 

I could be part of this also. I am not to the same level as you experts but could have a try.

 
 
Sent: Wednesday, July 28, 2021 at 7:28 PM
From: "Jorge Garzón via groups.io" <iberiaDX@...>
To: main@UltralightDX.groups.io
Subject: Re: [UltralightDX] March 2021 South American Ultralight DXpedition by Martin Butera
Ji,
Great work from Martin!!
Perhaps there is not an evident two-way propagation happening every time we listen to the band. Theorically everything is possible, bit how and when almost impossible to predict.

Something never happened before was to organize a global MW DXP with UL/Small Portables and FSL. We could try one or two combined dates in the year and then combine and share together. Imagine... Peter in Central África, Gary in Oregon, Paul in Tasmania, Paul Logan in Eire, Alaska, and me in Spain/Portugal. That could be the first Worldwide MW UL DXP in the history.

73
--
Jorge Garzón (EB7EFA · EA1036 SWL) 
QTH: IN83ag / 43º15' N · 03º56' W
Urb. San Roque 95, casa 5 (Villasevil)
39698 Santiurde de Toranzo (ESPAÑA - SPAIN)
..................................................................................
Blog: IberiaDX  · Twitter: @IberiaDX

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