Date   

Re: Air loop vs Ferrite loop

Rik
 

Ferrite loops can provide much narrower pick up patterns than air core in my experience. I do not know what design factors control which are very narrow. I have a coil I use over a 16 inch long stack of ferrite which is extremely directional allowing me to choose a number of stations on AM frequencies at night from here in Connecticut USA. It will not hear very distant DX stations, it only chooses 2-4 stations on some  frequencies  within a couple hundred miles on the best evenings. On 1250 AM I have chosen between stations in MA, NY, PA and NJ from CT.

So it does depend on your goals for a better antenna.

Even if you do plan to build your own, you may as well look at commercially successful designs. I have four PK Loops from Australia, the W6LVP amplified single turn loops with two size elements. Besides the home made ferrite stack, Litz on single 9 and 12 inch ferrite cores, a much larger Stormwise ferrite , home made box loops in 2 and 4 foot square sizes etc. They are all different, and each is probably better for different uses. In general the large tuned  air core loops often  hear more than one station per frequency at a time at night, but not during the day.

-FARMERIK


Re: https://groups.io/

mediumwavedx
 

Cant't wait. I hate Yahoo.

Also Yahoo's infinite forum scroll is buggy in most Android browsers. They know about it but refuse to fix it.

Bill


Re: Air loop vs Ferrite loop

maxim_sdr
 

Steven, nice receiver, thank you for the video and comparative infos that give me an idea of what to expect.
Michael, i agree with what you say, i did not think of using a coupling loop hard wired to the D-808, that will work for a standard receiver but not for last generation radios with Silicon Labs chip.
You give me the chance to make the poit on this: there are 3 possible ways to connect a air loop antenna:

1) Using a tuning capacitor in parallel and passively coupling to the internal ferrite antenna keeping the receiver closed to it.
this will work in any radio equipped with a ferrite antenna.

2) Winding a coupling loop on the air loop antenna and hard wiring this secondary loop to the input of the receiver. The air loop antenna is still tuned with its capacitor in parallel.
This will work on a classic receiver like Steven confirmed (and like many of us have done before for the HF). It will also work with a old generation portable receiver without auto tuning chip after having disconnected its internal ferrite antenna (not sure if some impedance transformer is needed in this case). It will not work on the D-808 or any other last generation DSP radio because the internal chip will try to tune the small coupling loop but its inducance will be out of range.

3) Connecting the air loop antenna directly to the input of the receiver without using a tuning capacitor.
It will work only on the last generation portable radios with DSP chip like the D-808, after having disconnected the internal ferrite antenna of course.
The characteristics of the external air loop are specified in the Silicon Labs Design Guidelines AN383 (inductange in the 180 to 450uH range).
That document also mentions a inductance transformer to be used only when the loop is just a small wrap of wire, to rise the inductance from 10–20 μH to the 180 to 450uH range needed from the receiver but this is not our case.

Methods number 1 and 3 are the ones that i will be using for my Xhdata D-808 and method number 2 is the one i would use for the SDR receiver.


Re: https://groups.io/

Russ Edmunds
 

The folks at groups.io have done a good job of making this easy. If there are difficulties, they'll be because of Yahoo Groups. That's not to say there's anything intentional - in fact I suspect the more groups who leave Yahoo, the better they'll like it. It's just that the parade of technical problems which have plagued Yahoo groups for several years now is still continuing.


Russ Edmunds

WB2BJH

Blue Bell, PA

Grid FN20id


From: ultralightdx@... on behalf of Robert Ross va3sw@... [ultralightdx]
Sent: Saturday, January 5, 2019 9:51:30 AM
To: Ultralight DX List
Subject: Re: [ultralightdx] Re: https://groups.io/
 
 



On Jan 5, 2019, at 08:51, Russ Edmunds wb2bjh@... [ultralightdx] <ultralightdx@yahoogroups..com> wrote:


It should not be necessary for individuals to join the new group. All existing members will be transferred as part of the process. In fact, as I am already a member or moderator of other groups on groups.io I have already received a notification of the impending transfer from groups.io.

Russ Edmunds

WB2BJH

Blue Bell, PA

Grid FN20id




Well….that will make things a lot easier! I joined the new group this morning, so I am already there. Once the group gets final io approval, I’ll see if I am shown as a Co-Owner/Moderator.

73..ROB VA3SW

Robert Ross
London, Ontario CANADA


Re: https://groups.io/

robert ross
 



On Jan 5, 2019, at 08:51, Russ Edmunds wb2bjh@... [ultralightdx] <ultralightdx@...> wrote:


It should not be necessary for individuals to join the new group. All existing members will be transferred as part of the process. In fact, as I am already a member or moderator of other groups on groups.io I have already received a notification of the impending transfer from groups.io.

Russ Edmunds

WB2BJH

Blue Bell, PA

Grid FN20id




Well….that will make things a lot easier! I joined the new group this morning, so I am already there. Once the group gets final io approval, I’ll see if I am shown as a Co-Owner/Moderator.

73..ROB VA3SW

Robert Ross
London, Ontario CANADA


Re: https://groups.io/

Russ Edmunds
 

It should not be necessary for individuals to join the new group. All existing members will be transferred as part of the process. In fact, as I am already a member or moderator of other groups on groups.io I have already received a notification of the impending transfer from groups.io.


Russ Edmunds

WB2BJH

Blue Bell, PA

Grid FN20id




From: ultralightdx@... on behalf of D1028Gary@... [ultralightdx]
Sent: Friday, January 4, 2019 11:51 PM
To: ultralightdx@...
Subject: Re: [ultralightdx] Re: https://groups.io/
 
 

FYI to All Group Members,

The new UltralightDX@groups.io  group has been created, but is not yet officially "approved" (which should take less than a day, according to Groups io). Please wait for additional information about the transition.

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




-----Original Message-----
From: D1028Gary@... [ultralightdx]
To: ultralightdx
Sent: Fri, Jan 4, 2019 8:13 pm
Subject: Re: [ultralightdx] Re: https://groups.io/

 
Thanks Tony (and all),

Fellow Ultralightdx Moderator Rob Ross and I have had our discussion, and we both agree that a transition to Groups io would be a good idea. We will proceed with the transition, assuming that Yahoo doesn't try to torpedo our ship as it departs the harbo(u)r.

Gary
 


-----Original Message-----
From: Tony King dx4me2@... [ultralightdx] <ultralightdx@...>
To: ultralightdx <ultralightdx@...>
Sent: Fri, Jan 4, 2019 7:47 pm
Subject: [ultralightdx] Re: https://groups.io/

 
Moving to groups.io
Yahoo have put a spanner in the works in the last week disrupting the transfer of sites and are working on a workaround so delays can be expected at this time. Worth the wait. As they mirror the yahoo site it still remains but becomes redundant. My last post announced the new site.
Cheers,
Tony k in so land


Re: Air loop vs Ferrite loop

steven
 

Hi Max,
I have only made one FSL antenna, and it works great both indoors and out.
My FSL is a 4" one. (30 ferrite rods)
My findings were, in direct comparison checks/tests that my 4" FSL gave approx the same signal as my 2 foot box loop/air cored loop.
Inductively coupled or a coupling loop works fine both antennas.
I have added a link to a short youtube video of both my FSL and Box loop.
Regards,
Steven,
Scotland.







On Saturday, 5 January 2019, 10:40:33 GMT, Michael michael.setaazul@... [ultralightdx] wrote:


 

Max, it will indeed be a pragmatic compromise. The D808, with which
I am not familiar, will probably have an auto-tuned internal ferrite.
Coupling or hard-wiring between a tuned external ferrite or loop and
the D808 frontend can be determinant - and tricky if external
tuning has to "compete" with internal software tuning. Inductive
coupling to the internal ferrite might work better, resulting
in a double-tuned frontend, manual tracking automatic. Disconnecting
the internal ferrite and allowing the internal autotune to tune
the external ferrite or loop might work well if the inductance
of the external aerial is well matched. Time to experiment!

Michael UK

On Samstag.05.01.19 09:23, max2006@... [ultralightdx] wrote:
> Thank you for your replies, the bigger the better, i know, but i am
> insterested to find the equivalent size, i do not care about vintage or
> aesthtic look, i want to make a loop that can be folded, to use at home
> or bring with me for trips in the weekends but considered that it has to
> be used at home i cannot follow the rule the bigger the better nor i
> want to make it undersized so that a 200x10 ferrite is still better.
> 8-10 inch looks to me a bit too small, i don't think it will give any
> advantage over the stock ferrite antenna of my  Xhdata D-808; at the
> moment i am using a 16 inch loop made with ribbon cable using alternate
> wires to reduce parassite capacity between the loops and i have some
> improvement with weak signals but i don't know if compared to a 200x10
> ferrite would still give some adavantage.
> Also has to be considered that i use the air loop as a passive antenna
> with tuning capacitor but i may also insert a jack to the radio to
> disconnect the i nternal ferrite and plug it directy without capacitor,
> i don't know if doing so will improve the signal.
>
> Anyone made a direct comparison?
>
>


Virus-free. www.avg.com


Re: Air loop vs Ferrite loop

Michael <michael.setaazul@...>
 

Max, it will indeed be a pragmatic compromise. The D808, with which
I am not familiar, will probably have an auto-tuned internal ferrite.
Coupling or hard-wiring between a tuned external ferrite or loop and
the D808 frontend can be determinant - and tricky if external
tuning has to "compete" with internal software tuning. Inductive
coupling to the internal ferrite might work better, resulting
in a double-tuned frontend, manual tracking automatic. Disconnecting
the internal ferrite and allowing the internal autotune to tune
the external ferrite or loop might work well if the inductance
of the external aerial is well matched. Time to experiment!

Michael UK

On Samstag.05.01.19 09:23, max2006@email.it [ultralightdx] wrote:
Thank you for your replies, the bigger the better, i know, but i am insterested to find the equivalent size, i do not care about vintage or aesthtic look, i want to make a loop that can be folded, to use at home or bring with me for trips in the weekends but considered that it has to be used at home i cannot follow the rule the bigger the better nor i want to make it undersized so that a 200x10 ferrite is still better.
8-10 inch looks to me a bit too small, i don't think it will give any advantage over the stock ferrite antenna of my  Xhdata D-808; at the moment i am using a 16 inch loop made with ribbon cable using alternate wires to reduce parassite capacity between the loops and i have some improvement with weak signals but i don't know if compared to a 200x10 ferrite would still give some adavantage.
Also has to be considered that i use the air loop as a passive antenna with tuning capacitor but i may also insert a jack to the radio to disconnect the i nternal ferrite and plug it directy without capacitor, i don't know if doing so will improve the signal.
Anyone made a direct comparison?


Re: Air loop vs Ferrite loop

maxim_sdr
 

Thank you for your replies, the bigger the better, i know, but i am insterested to find the equivalent size, i do not care about vintage or aesthtic look, i want to make a loop that can be folded, to use at home or bring with me for trips in the weekends but considered that it has to be used at home i cannot follow the rule the bigger the better nor i want to make it undersized so that a 200x10 ferrite is still better.
8-10 inch looks to me a bit too small, i don't think it will give any advantage over the stock ferrite antenna of my  Xhdata D-808; at the moment i am using a 16 inch loop made with ribbon cable using alternate wires to reduce parassite capacity between the loops and i have some improvement with weak signals but i don't know if compared to a 200x10 ferrite would still give some adavantage.
Also has to be considered that i use the air loop as a passive antenna with tuning capacitor but i may also insert a jack to the radio to disconnect the internal ferrite and plug it directy without capacitor, i don't know if doing so will improve the signal.

Anyone made a direct comparison?


Re: https://groups.io/

Paul Blundell
 

Sounds great. I have just signed up :)

I am happy to help out in any way possible, it might also be a good chance to sort some the files and update some as needed.

On Sat, Jan 5, 2019 at 3:52 PM D1028Gary@... [ultralightdx] <ultralightdx@...> wrote:
 

FYI to All Group Members,

The new UltralightDX@groups.io  group has been created, but is not yet officially "approved" (which should take less than a day, according to Groups io). Please wait for additional information about the transition.

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




-----Original Message-----
From: D1028Gary@... [ultralightdx] <ultralightdx@...>
To: ultralightdx <ultralightdx@...>
Sent: Fri, Jan 4, 2019 8:13 pm
Subject: Re: [ultralightdx] Re: https://groups.io/

 
Thanks Tony (and all),

Fellow Ultralightdx Moderator Rob Ross and I have had our discussion, and we both agree that a transition to Groups io would be a good idea. We will proceed with the transition, assuming that Yahoo doesn't try to torpedo our ship as it departs the harbo(u)r.

Gary
 


-----Original Message-----
From: Tony King dx4me2@... [ultralightdx] <ultralightdx@...>
To: ultralightdx <ultralightdx@...>
Sent: Fri, Jan 4, 2019 7:47 pm
Subject: [ultralightdx] Re: https://groups.io/

 
Moving to groups.io
Yahoo have put a spanner in the works in the last week disrupting the transfer of sites and are working on a workaround so delays can be expected at this time. Worth the wait. As they mirror the yahoo site it still remains but becomes redundant. My last post announced the new site.
Cheers,
Tony k in so land



--
Paul


Re: Air loop vs Ferrite loop

Michael <michael.setaazul@...>
 

Agreed, Steve.
A longer butt-glued tuned ferrite is better than a short one.
But extending it further makes it unwieldy and accident-prone -
and brings no further audible improvement.

A tuned frame aerial delivers vintage excellence, the bigger the better.

Of course, an FSL enables bitcoin-winners to wipe the floor with the rest of us!

Michael UK

On Samstag.05.01.19 05:04, STEVE ratzlaffsteve@gmail.com [ultralightdx] wrote:
Purely my own opinion and not based on direct comparison tests, but I'd say a square loop of 8-10 inches might give equivalent results to a 200 mm long ferrite rod. I'm assuming both loops are tuned with a capacitor, not untuned loops.
On 1/4/2019 9:19 PM, max2006@email.it [ultralightdx] wrote:

Hi, i have a question, what is the size that i should consider for a square air loop made with standard wire to give the same result of a ferrite antenna size 200x10mm?


Re: Air loop vs Ferrite loop

Steve Ratzlaff
 

Purely my own opinion and not based on direct comparison tests, but I'd say a square loop of 8-10 inches might give equivalent results to a 200 mm long ferrite rod. I'm assuming both loops are tuned with a capacitor, not untuned loops. And if you could use Litz wire of maybe 175/46 or larger, that would help too. But if just standard wire then use the largest gauge you can find/afford, hopefully #18 gauge or larger (in AWG wire size, I don't know the metric equivalent size).

Good luck!

73,

Steve AA7U

On 1/4/2019 9:19 PM, max2006@... [ultralightdx] wrote:
 

Hi, i have a question, what is the size that i should consider for a square air loop made with standard wire to give the same result of a ferrite antenna size 200x10mm?


Re: https://groups.io/

Gary DeBock
 

FYI to All Group Members,

The new UltralightDX@groups.io  group has been created, but is not yet officially "approved" (which should take less than a day, according to Groups io). Please wait for additional information about the transition.

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




-----Original Message-----
From: D1028Gary@... [ultralightdx]
To: ultralightdx
Sent: Fri, Jan 4, 2019 8:13 pm
Subject: Re: [ultralightdx] Re: https://groups.io/

 
Thanks Tony (and all),

Fellow Ultralightdx Moderator Rob Ross and I have had our discussion, and we both agree that a transition to Groups io would be a good idea. We will proceed with the transition, assuming that Yahoo doesn't try to torpedo our ship as it departs the harbo(u)r.

Gary
 


-----Original Message-----
From: Tony King dx4me2@... [ultralightdx] <ultralightdx@...>
To: ultralightdx <ultralightdx@...>
Sent: Fri, Jan 4, 2019 7:47 pm
Subject: [ultralightdx] Re: https://groups.io/

 
Moving to groups.io
Yahoo have put a spanner in the works in the last week disrupting the transfer of sites and are working on a workaround so delays can be expected at this time. Worth the wait. As they mirror the yahoo site it still remains but becomes redundant. My last post announced the new site.
Cheers,
Tony k in so land


Air loop vs Ferrite loop

maxim_sdr
 

Hi, i have a question, what is the size that i should consider for a square air loop made with standard wire to give the same result of a ferrite antenna size 200x10mm?


Re: https://groups.io/

Gary DeBock
 

Thanks Tony (and all),

Fellow Ultralightdx Moderator Rob Ross and I have had our discussion, and we both agree that a transition to Groups io would be a good idea. We will proceed with the transition, assuming that Yahoo doesn't try to torpedo our ship as it departs the harbo(u)r.

Gary
 


-----Original Message-----
From: Tony King dx4me2@... [ultralightdx]
To: ultralightdx
Sent: Fri, Jan 4, 2019 7:47 pm
Subject: [ultralightdx] Re: https://groups.io/

 
Moving to groups.io
Yahoo have put a spanner in the works in the last week disrupting the transfer of sites and are working on a workaround so delays can be expected at this time. Worth the wait. As they mirror the yahoo site it still remains but becomes redundant. My last post announced the new site.
Cheers,
Tony k in so land


Re: https://groups.io/

Tony King <dx4me2@...>
 

Moving to groups.io
Yahoo have put a spanner in the works in the last week disrupting the transfer of sites and are working on a workaround so delays can be expected at this time. Worth the wait. As they mirror the yahoo site it still remains but becomes redundant. My last post announced the new site.
Cheers,
Tony k in so land


Re: https://groups.io/

Paul Blundell
 

It seems like it will be the best way forward.

I have had issues with files not uploading and post not coming through for hours in some cases. I was looking for a file I uploaded a few years ago which was here one day, gone a week later and then it came back.



Sent from my Samsung GALAXY S5


-------- Original message --------
From: "Russ Edmunds wb2bjh@... [ultralightdx]" <ultralightdx@...>
Date: 5/01/2019 5:57 AM (GMT+10:00)
To: ultralightdx@...
Subject: Re: [ultralightdx] https://groups.io/

 

I'm currently a member or moderator of 4 groups which have moved from Yahoo Groups to groups.io, and it is painless. Beyond that, groups.io, being more or less of a specialist organization dedicated to groups offers some features that Yahoo never did. I'd recommend the move, especially given that the future of Yahoo following its recent acquisition is at best cloudy.


Russ Edmunds

WB2BJH

Blue Bell, PA

Grid FN20id




From: ultralightdx@... <ultralightdx@...> on behalf of theod438@... [ultralightdx] <ultralightdx@...>
Sent: Friday, January 4, 2019 1:02 PM
To: ultralightdx@...
Subject: Re: [ultralightdx] https://groups.io/
 
 

What am I allowed to say , but yairs!  But then I'm only the Hired Help Here, not a contributor.  <g>

From observing other groups doing the switch, it seems to be painless... and although I personally don't have issues/problems with Yahoo! as others appear to experience, <groups.io> perform well.

TD


Re: https://groups.io/

Russ Edmunds
 

I'm currently a member or moderator of 4 groups which have moved from Yahoo Groups to groups.io, and it is painless. Beyond that, groups.io, being more or less of a specialist organization dedicated to groups offers some features that Yahoo never did. I'd recommend the move, especially given that the future of Yahoo following its recent acquisition is at best cloudy.


Russ Edmunds

WB2BJH

Blue Bell, PA

Grid FN20id




From: ultralightdx@... on behalf of theod438@... [ultralightdx]
Sent: Friday, January 4, 2019 1:02 PM
To: ultralightdx@...
Subject: Re: [ultralightdx] https://groups.io/
 
 

What am I allowed to say , but yairs!  But then I'm only the Hired Help Here, not a contributor. 

From observing other groups doing the switch, it seems to be painless... and although I personally don't have issues/problems with Yahoo! as others appear to experience, perform well.

TD


Re: https://groups.io/

theod438@...
 

What am I allowed to say , but yairs!  But then I'm only the Hired Help Here, not a contributor.  <g>

From observing other groups doing the switch, it seems to be painless... and although I personally don't have issues/problems with Yahoo! as others appear to experience, <groups.io> perform well.

TD


Re: https://groups.io/

Paul Blundell
 

I am happy to help out with the new group if you need it.

Paul



Sent from my Samsung GALAXY S5


-------- Original message --------
From: "D1028Gary@... [ultralightdx]" <ultralightdx@...>
Date: 4/01/2019 6:42 PM (GMT+10:00)
To: ultralightdx@...
Subject: Re: [ultralightdx] https://groups.io/

 

<<<   Yes please.   >>>

Hello Andy,

Tony King also suggested this a few months back, so the Kiwi vote is unanimous. I'm sure that soon, Theo D. and Tony Magon will concur.

I'll discuss this with my primary partner-in-crime Rob Ross, who is also an Ultralightdx Moderator (and who has been running this show with me for 10+ years). Tony K. assured me that the process is easy, and that we only need to take the plunge.

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


    


-----Original Message-----
From: 'zl3ag@...' zl3ag@... [ultralightdx] <ultralightdx@...>
To: ultralightdx <ultralightdx@...>
Sent: Thu, Jan 3, 2019 10:14 pm
Subject: Re: [ultralightdx] https://groups.io/

 

Yes please.

On 4/01/19 6:21 PM, tanger32au@... [ultralightdx] wrote:
> I have noticed more and more issues with Yahoo Groups of late, a number of my other Yahoo Groups have moved to https://groups.io/.
>
>
> Has any thought been given to us also moving across?
>
>
> Paul
>

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