Date   

Re: One-off special...Indoor HF Active Loop antenna

Adrian Rawlings
 

How about building the equivalent of an goniometer, such that the antenna doesn't have to rotate?

You could do it 'old school' by having two antennas mounted at right angles, which feed two coils which are also at right angles.

Then, use a pick-up coil mounted in the field of these two coils and which is capable of rotating, such that it can be adjusted to pick up suitable portions from the two driving coils. This kind of arrangement is used with DF loops on ships and aircraft.


Re: One-off special...Indoor HF Active Loop antenna

Graham J Smith G4NMD
 

Hear Hear

Graham G4NMD. Wishing hard


On 27 Sep 2018, at 16:35, Tom Crosbie G6PZZ <tom@...> wrote:

I’ve been experimenting with indoor MW loops, pan and tilt being achieved using a camera tripod so the direction indicator is by eyeball. I wanted to mount the loop further away and use some form of remote control. I found some low-speed (2rpm) high torque motors on eBay that looked very capable. 12V DC in one terminal to go clockwise and the same into another to go backwards. Again direction is by eyeball and the tilt has gone for now! These are twice the price of David’s suggestion so I may go back to the drawing board.

 

But to get back to the PSU, I would advocate selling the antenna without one. I would suggest many readers have the means to cobble something together, or have an 12V underused linear supply. I recently purchased some PCB’s that accommodate some capacitors and an LM78XX. This would be fed from my 12V shack supply giving me a range of lower voltages dictated by the choice of LM78XX.

 

It may be possible to design a circuit that would be suitable and offer as a kit without requiring CE approval, perhaps even a populated PCB. I may be wrong on this so I’m ready to be corrected. My knowledge of approvals is both limited and dated.

 

As to the antenna itself, a lower frequency response would definitely suit my listening requirements and go straight onto my Wishlist.

 

Tom G6PZZ

 

From: CrossCountryWireless@groups.io <CrossCountryWireless@groups.io> On Behalf Of David Cutter via Groups.Io
Sent: 27 September 2018 14:47
To: CrossCountryWireless@groups.io
Subject: Re: [CrossCountryWireless] One-off special...Indoor HF Active Loop antenna

 

I started to design a small rotator from a BBQ spit rotator.  Amazon has them at around £5. The battery is integral and I think it could be done without much ado.  It is just the business end, no controller or direction indicator.  Should be a great little project for someone with the time…whatever that is. 

David G3UNA

 

From: CrossCountryWireless@groups.io [mailto:CrossCountryWireless@groups.io] On Behalf Of Greg_M6ORT
Sent: 27 September 2018 14:02
To: david via Groups.Io; CrossCountryWireless@groups.io
Subject: Re: [CrossCountryWireless] One-off special...Indoor HF Active Loop antenna

 

With regards to rotators...  The only one I could find that was a TV type and cheaper was on a well known internet auction site.  It had to come from the US, but the company had signed up for the scheme where the postage covers all the p&p, customs and vat duty etc so you didn't have the performance getting it into the country.  It was a Channel Master 9521.  Think it was around £142 all in compared to silly cash for ham brands, although not as good as the £80 you used to be able to pay.

Best wishes

Greg

M6ORT 

 


From: CrossCountryWireless@groups.io <CrossCountryWireless@groups.io> on behalf of david via Groups.Io <zinc65@...>
Sent: 27 September 2018 12:40
To: CrossCountryWireless@groups.io
Subject: Re: [CrossCountryWireless] One-off special...Indoor HF Active Loop antenna

 

An HF active antenna that manages a good s/n ratio at LF would be greatly appreciated.
The bigger problem appears to be sourcing that 'TV Rotator'. If you only need to turn a small loop like the CCW antenna, all the rotators on today's market are over-specified and expensive.

David, GM8XBZ

-----Original Message-----
From: CrossCountryWireless@groups.io <CrossCountryWireless@groups.io> On Behalf Of David Cutter via Groups.Io
Sent: 27 September 2018 10:59
To: CrossCountryWireless@groups.io
Subject: Re: [CrossCountryWireless] One-off special...Indoor HF Active Loop antenna

Well done, Chris. 

<snip>

I can imagine using an inverted U for tx and rx, then this receive-only antenna as the other, perhaps on a small TV rotator. 

 



Re: One-off special...Indoor HF Active Loop antenna

Tom Crosbie G6PZZ
 

I’ve been experimenting with indoor MW loops, pan and tilt being achieved using a camera tripod so the direction indicator is by eyeball. I wanted to mount the loop further away and use some form of remote control. I found some low-speed (2rpm) high torque motors on eBay that looked very capable. 12V DC in one terminal to go clockwise and the same into another to go backwards. Again direction is by eyeball and the tilt has gone for now! These are twice the price of David’s suggestion so I may go back to the drawing board.

 

But to get back to the PSU, I would advocate selling the antenna without one. I would suggest many readers have the means to cobble something together, or have an 12V underused linear supply. I recently purchased some PCB’s that accommodate some capacitors and an LM78XX. This would be fed from my 12V shack supply giving me a range of lower voltages dictated by the choice of LM78XX.

 

It may be possible to design a circuit that would be suitable and offer as a kit without requiring CE approval, perhaps even a populated PCB. I may be wrong on this so I’m ready to be corrected. My knowledge of approvals is both limited and dated.

 

As to the antenna itself, a lower frequency response would definitely suit my listening requirements and go straight onto my Wishlist.

 

Tom G6PZZ

 

From: CrossCountryWireless@groups.io <CrossCountryWireless@groups.io> On Behalf Of David Cutter via Groups.Io
Sent: 27 September 2018 14:47
To: CrossCountryWireless@groups.io
Subject: Re: [CrossCountryWireless] One-off special...Indoor HF Active Loop antenna

 

I started to design a small rotator from a BBQ spit rotator.  Amazon has them at around £5. The battery is integral and I think it could be done without much ado.  It is just the business end, no controller or direction indicator.  Should be a great little project for someone with the time…whatever that is. 

David G3UNA

 

From: CrossCountryWireless@groups.io [mailto:CrossCountryWireless@groups.io] On Behalf Of Greg_M6ORT
Sent: 27 September 2018 14:02
To: david via Groups.Io; CrossCountryWireless@groups.io
Subject: Re: [CrossCountryWireless] One-off special...Indoor HF Active Loop antenna

 

With regards to rotators...  The only one I could find that was a TV type and cheaper was on a well known internet auction site.  It had to come from the US, but the company had signed up for the scheme where the postage covers all the p&p, customs and vat duty etc so you didn't have the performance getting it into the country.  It was a Channel Master 9521.  Think it was around £142 all in compared to silly cash for ham brands, although not as good as the £80 you used to be able to pay.

Best wishes

Greg

M6ORT 

 


From: CrossCountryWireless@groups.io <CrossCountryWireless@groups.io> on behalf of david via Groups.Io <zinc65@...>
Sent: 27 September 2018 12:40
To: CrossCountryWireless@groups.io
Subject: Re: [CrossCountryWireless] One-off special...Indoor HF Active Loop antenna

 

An HF active antenna that manages a good s/n ratio at LF would be greatly appreciated.
The bigger problem appears to be sourcing that 'TV Rotator'. If you only need to turn a small loop like the CCW antenna, all the rotators on today's market are over-specified and expensive.

David, GM8XBZ

-----Original Message-----
From: CrossCountryWireless@groups.io <CrossCountryWireless@groups.io> On Behalf Of David Cutter via Groups.Io
Sent: 27 September 2018 10:59
To: CrossCountryWireless@groups.io
Subject: Re: [CrossCountryWireless] One-off special...Indoor HF Active Loop antenna

Well done, Chris. 

<snip>

I can imagine using an inverted U for tx and rx, then this receive-only antenna as the other, perhaps on a small TV rotator. 

 



Re: One-off special...Indoor HF Active Loop antenna

David Cutter
 

I started to design a small rotator from a BBQ spit rotator.  Amazon has them at around £5. The battery is integral and I think it could be done without much ado.  It is just the business end, no controller or direction indicator.  Should be a great little project for someone with the time…whatever that is. 

David G3UNA

 

From: CrossCountryWireless@groups.io [mailto:CrossCountryWireless@groups.io] On Behalf Of Greg_M6ORT
Sent: 27 September 2018 14:02
To: david via Groups.Io; CrossCountryWireless@groups.io
Subject: Re: [CrossCountryWireless] One-off special...Indoor HF Active Loop antenna

 

With regards to rotators...  The only one I could find that was a TV type and cheaper was on a well known internet auction site.  It had to come from the US, but the company had signed up for the scheme where the postage covers all the p&p, customs and vat duty etc so you didn't have the performance getting it into the country.  It was a Channel Master 9521.  Think it was around £142 all in compared to silly cash for ham brands, although not as good as the £80 you used to be able to pay.

Best wishes

Greg

M6ORT 

 


From: CrossCountryWireless@groups.io <CrossCountryWireless@groups.io> on behalf of david via Groups.Io <zinc65@...>
Sent: 27 September 2018 12:40
To: CrossCountryWireless@groups.io
Subject: Re: [CrossCountryWireless] One-off special...Indoor HF Active Loop antenna

 

An HF active antenna that manages a good s/n ratio at LF would be greatly appreciated.
The bigger problem appears to be sourcing that 'TV Rotator'. If you only need to turn a small loop like the CCW antenna, all the rotators on today's market are over-specified and expensive.

David, GM8XBZ

-----Original Message-----
From: CrossCountryWireless@groups.io <CrossCountryWireless@groups.io> On Behalf Of David Cutter via Groups.Io
Sent: 27 September 2018 10:59
To: CrossCountryWireless@groups.io
Subject: Re: [CrossCountryWireless] One-off special...Indoor HF Active Loop antenna

Well done, Chris. 

<snip>

I can imagine using an inverted U for tx and rx, then this receive-only antenna as the other, perhaps on a small TV rotator. 

 




Re: One-off special...Indoor HF Active Loop antenna

K4KDR
 

Solid Signal has a number of AZ-only “TV” rotators:
 
 
... in particular, for years I’ve used an earlier version similar to:
 
 
... and it’s even computer-controllable with a USB IR adapter that the PSTRotator software talks to perfectly.
 
The how-to on that is a little out-dated since software versions & product availability change constantly, but if anyone is interested that’s at:
 
 
-Scott,  K4KDR
 
 
======================================
 
 
 

From: Greg_M6ORT
Sent: Thursday, September 27, 2018 9:01 AM
Subject: Re: [CrossCountryWireless] One-off special...Indoor HF Active Loop antenna
 
With regards to rotators...  The only one I could find that was a TV type and cheaper was on a well known internet auction site.  It had to come from the US, but the company had signed up for the scheme where the postage covers all the p&p, customs and vat duty etc so you didn't have the performance getting it into the country.  It was a Channel Master 9521.  Think it was around £142 all in compared to silly cash for ham brands, although not as good as the £80 you used to be able to pay.
Best wishes
Greg
M6ORT 
 

From: CrossCountryWireless@groups.io <CrossCountryWireless@groups.io> on behalf of david via Groups.Io <zinc65@...>
Sent: 27 September 2018 12:40
To: CrossCountryWireless@groups.io
Subject: Re: [CrossCountryWireless] One-off special...Indoor HF Active Loop antenna
 
An HF active antenna that manages a good s/n ratio at LF would be greatly appreciated.
The bigger problem appears to be sourcing that 'TV Rotator'. If you only need to turn a small loop like the CCW antenna, all the rotators on today's market are over-specified and expensive.

David, GM8XBZ

-----Original Message-----
From: CrossCountryWireless@groups.io <CrossCountryWireless@groups.io> On Behalf Of David Cutter via Groups.Io
Sent: 27 September 2018 10:59
To: CrossCountryWireless@groups.io
Subject: Re: [CrossCountryWireless] One-off special...Indoor HF Active Loop antenna

Well done, Chris. 

<snip>

I can imagine using an inverted U for tx and rx, then this receive-only antenna as the other, perhaps on a small TV rotator. 


Re: One-off special...Indoor HF Active Loop antenna

Greg_2e1gw
 

With regards to rotators...  The only one I could find that was a TV type and cheaper was on a well known internet auction site.  It had to come from the US, but the company had signed up for the scheme where the postage covers all the p&p, customs and vat duty etc so you didn't have the performance getting it into the country.  It was a Channel Master 9521.  Think it was around £142 all in compared to silly cash for ham brands, although not as good as the £80 you used to be able to pay.
Best wishes
Greg
M6ORT 


From: CrossCountryWireless@groups.io <CrossCountryWireless@groups.io> on behalf of david via Groups.Io <zinc65@...>
Sent: 27 September 2018 12:40
To: CrossCountryWireless@groups.io
Subject: Re: [CrossCountryWireless] One-off special...Indoor HF Active Loop antenna
 
An HF active antenna that manages a good s/n ratio at LF would be greatly appreciated.
The bigger problem appears to be sourcing that 'TV Rotator'. If you only need to turn a small loop like the CCW antenna, all the rotators on today's market are over-specified and expensive.

David, GM8XBZ

-----Original Message-----
From: CrossCountryWireless@groups.io <CrossCountryWireless@groups.io> On Behalf Of David Cutter via Groups.Io
Sent: 27 September 2018 10:59
To: CrossCountryWireless@groups.io
Subject: Re: [CrossCountryWireless] One-off special...Indoor HF Active Loop antenna

Well done, Chris. 

<snip>

I can imagine using an inverted U for tx and rx, then this receive-only antenna as the other, perhaps on a small TV rotator. 

 





Re: One-off special...Indoor HF Active Loop antenna

david
 

An HF active antenna that manages a good s/n ratio at LF would be greatly appreciated.
The bigger problem appears to be sourcing that 'TV Rotator'. If you only need to turn a small loop like the CCW antenna, all the rotators on today's market are over-specified and expensive.

David, GM8XBZ

-----Original Message-----
From: CrossCountryWireless@groups.io <CrossCountryWireless@groups.io> On Behalf Of David Cutter via Groups.Io
Sent: 27 September 2018 10:59
To: CrossCountryWireless@groups.io
Subject: Re: [CrossCountryWireless] One-off special...Indoor HF Active Loop antenna

Well done, Chris.

<snip>

I can imagine using an inverted U for tx and rx, then this receive-only antenna as the other, perhaps on a small TV rotator.


Re: One-off special...Indoor HF Active Loop antenna

David Cutter
 

Well done, Chris. 

 

Two things come to mind: when you say it out-performed the inverted U, I imagine you mean it was quieter, however do you mean that you could hear signals not heard on the inverted U?

 

Re power supplies: for the ultimate in quiet listening there's always the option of batteries in an outboard cassette, such as the re-chargeable LiIon which I can now get it in a neat 12V package.  There's always the option of using the shack linear dc supply.

 

Very many folks have unbelievably noisy local environments making communications unworkable from home; but with a quiet receive system it makes it perfectly possible to have meaningful communications if the transceiver can handle 2 antennas.  I built a changeover antenna switch for a friend whose radio has only one antenna socket, perhaps you could make such a unit to accompany your quiet receive systems.

 

I can imagine using an inverted U for tx and rx, then this receive-only antenna as the other, perhaps on a small TV rotator. 

 

David G3UNA

 

From: CrossCountryWireless@groups.io [mailto:CrossCountryWireless@groups.io] On Behalf Of Chris Moulding
Sent: 26 September 2018 21:12
To: CrossCountryWireless@groups.io
Subject: [CrossCountryWireless] One-off special...Indoor HF Active Loop antenna

 

Sometimes we are asked to do one-off versions of our products for special applications, very often it helps push the development of our products into new areas.

Recently I was asked by a short wave listener who only lives a few miles from us if we could build an indoor version of our HF Active Loop antenna. It's not possible for him to erect outdoor antennas but he still wants an antenna that can hear DX and non directional beacons around 300 kHz.

It's an interesting challenge on two fronts. First it has too look good for indoor use so two separate boxes and ethernet cable connection were out and it has to have some form of flat mount to fit on a table. All the amplifier and power filtering was fitted into what would usually be the head unit and I sourced a rather nice oak plinth usually used for making trophies as a base.

The second challenge was even tougher. The standard loop antenna we make at present rolls off at 500 kHz. I used a revised circuit made for another "special" loop antenna but changed the biasing arrangement so that it would work better at low frequencies. I overdid it a bit as I can now hear the VLF submarine transmission from the Anthorn radio station in north west England on 22.1 kHz with the loop. To allow it to be used indoors I added a common mode filter to the antenna input to stop the loop acting as an electric field probe picking up RF noise from the house electrical system. I adder extra common mode filters to the DC input and RF output to further isolate the antenna from noise.

Testing it on HF shows that it will receive DX as ordered. Yesterday evening I was doing comparison tests with a Terminated Inverted U antenna (the lowest noise antenna here so far) on the 80m amateur band and the loop out-performed it even though it was mounted indoors next to two computers.

The improved loop amplifier design is now going to be added to the existing HF Active Loop antenna extending the frequency coverage from 20 kHz to 70 MHz with a dipole loop pattern and multilobe pattern up to 148 MHz.

Unfortunately the indoor version is likely to remain a one-off as I can no longer source a RF quiet linear 12V power supply due to EU regulations outlawing them replacing them with switch mode power supplies in the quest for power efficiency. Every switch mode power supply I've tried generates too much noise even with the common mode filters added to the antenna amplifier. I'm supplying the last of my stock of linear power supplies with it.

Here are some photos of the antenna taken today before it's delivered to the customer tomorrow.



Regards,

Chris


Re: One-off special...Indoor HF Active Loop antenna

Chris Moulding
 

Hi Graham,

I've had a few suggestions already about supplying your own supply so I might be persuaded to make a few more.

Whenever I mention VLF in the forum or on the Facebook page I'm always surprised at the amount of interest in it and the number of people who have had a professional interest in it.

Regards,

Chris G4HYG

--
Chris Moulding
Cross Country Wireless
7 Thirlmere Grove, Bolton, Lancs, BL4 0QB, UK
Tel/fax: +44(0)1204 410626
Mob/workshop: +44(0)7752 391908
Secure email: g4hyg@protonmail.com
Website: http://www.crosscountrywireless.net
Groups.io: https://groups.io/g/CrossCountryWireless

On 26/09/18 21:56, Graham J Smith G4NMD wrote:
But.... if one could supply ones own non-noisy supply.....
I had a long association with Anthorn, Inskip, Rugby and acrimony
Graham NMD
On 26 Sep 2018, at 21:12, Chris Moulding <chrism@crosscountrywireless.net <mailto:chrism@crosscountrywireless.net>> wrote:

Sometimes we are asked to do one-off versions of our products for special applications, very often it helps push the development of our products into new areas.

Recently I was asked by a short wave listener who only lives a few miles from us if we could build an indoor version of our HF Active Loop antenna. It's not possible for him to erect outdoor antennas but he still wants an antenna that can hear DX and non directional beacons around 300 kHz.

It's an interesting challenge on two fronts. First it has too look good for indoor use so two separate boxes and ethernet cable connection were out and it has to have some form of flat mount to fit on a table. All the amplifier and power filtering was fitted into what would usually be the head unit and I sourced a rather nice oak plinth usually used for making trophies as a base.

The second challenge was even tougher. The standard loop antenna we make at present rolls off at 500 kHz. I used a revised circuit made for another "special" loop antenna but changed the biasing arrangement so that it would work better at low frequencies. I overdid it a bit as I can now hear the VLF submarine transmission from the Anthorn radio station in north west England on 22.1 kHz with the loop. To allow it to be used indoors I added a common mode filter to the antenna input to stop the loop acting as an electric field probe picking up RF noise from the house electrical system. I adder extra common mode filters to the DC input and RF output to further isolate the antenna from noise.

Testing it on HF shows that it will receive DX as ordered. Yesterday evening I was doing comparison tests with a Terminated Inverted U antenna (the lowest noise antenna here so far) on the 80m amateur band and the loop out-performed it even though it was mounted indoors next to two computers.

The improved loop amplifier design is now going to be added to the existing HF Active Loop antenna extending the frequency coverage from 20 kHz to 70 MHz with a dipole loop pattern and multilobe pattern up to 148 MHz.

Unfortunately the indoor version is likely to remain a one-off as I can no longer source a RF quiet linear 12V power supply due to EU regulations outlawing them replacing them with switch mode power supplies in the quest for power efficiency. Every switch mode power supply I've tried generates too much noise even with the common mode filters added to the antenna amplifier. I'm supplying the last of my stock of linear power supplies with it.

Here are some photos of the antenna taken today before it's delivered to the customer tomorrow.

<Indoor_active_loop1.jpg><Indoor_active_loop2.jpg>

Regards,

Chris


Re: One-off special...Indoor HF Active Loop antenna

Graham J Smith G4NMD
 

Damn spell check it was Crimond not acrimony


On 26 Sep 2018, at 21:56, Graham J Smith G4NMD <gjsmith@...> wrote:

But.... if one could supply ones own non-noisy supply.....

I had a long association with Anthorn, Inskip, Rugby and acrimony

Graham NMD


On 26 Sep 2018, at 21:12, Chris Moulding <chrism@...> wrote:

Sometimes we are asked to do one-off versions of our products for special applications, very often it helps push the development of our products into new areas.

Recently I was asked by a short wave listener who only lives a few miles from us if we could build an indoor version of our HF Active Loop antenna. It's not possible for him to erect outdoor antennas but he still wants an antenna that can hear DX and non directional beacons around 300 kHz.

It's an interesting challenge on two fronts. First it has too look good for indoor use so two separate boxes and ethernet cable connection were out and it has to have some form of flat mount to fit on a table. All the amplifier and power filtering was fitted into what would usually be the head unit and I sourced a rather nice oak plinth usually used for making trophies as a base.

The second challenge was even tougher. The standard loop antenna we make at present rolls off at 500 kHz. I used a revised circuit made for another "special" loop antenna but changed the biasing arrangement so that it would work better at low frequencies. I overdid it a bit as I can now hear the VLF submarine transmission from the Anthorn radio station in north west England on 22.1 kHz with the loop. To allow it to be used indoors I added a common mode filter to the antenna input to stop the loop acting as an electric field probe picking up RF noise from the house electrical system. I adder extra common mode filters to the DC input and RF output to further isolate the antenna from noise.

Testing it on HF shows that it will receive DX as ordered. Yesterday evening I was doing comparison tests with a Terminated Inverted U antenna (the lowest noise antenna here so far) on the 80m amateur band and the loop out-performed it even though it was mounted indoors next to two computers.

The improved loop amplifier design is now going to be added to the existing HF Active Loop antenna extending the frequency coverage from 20 kHz to 70 MHz with a dipole loop pattern and multilobe pattern up to 148 MHz.

Unfortunately the indoor version is likely to remain a one-off as I can no longer source a RF quiet linear 12V power supply due to EU regulations outlawing them replacing them with switch mode power supplies in the quest for power efficiency. Every switch mode power supply I've tried generates too much noise even with the common mode filters added to the antenna amplifier. I'm supplying the last of my stock of linear power supplies with it.

Here are some photos of the antenna taken today before it's delivered to the customer tomorrow.

<Indoor_active_loop1.jpg><Indoor_active_loop2.jpg>

Regards,

Chris


Re: One-off special...Indoor HF Active Loop antenna

Graham J Smith G4NMD
 

But.... if one could supply ones own non-noisy supply.....

I had a long association with Anthorn, Inskip, Rugby and acrimony

Graham NMD


On 26 Sep 2018, at 21:12, Chris Moulding <chrism@...> wrote:

Sometimes we are asked to do one-off versions of our products for special applications, very often it helps push the development of our products into new areas.

Recently I was asked by a short wave listener who only lives a few miles from us if we could build an indoor version of our HF Active Loop antenna. It's not possible for him to erect outdoor antennas but he still wants an antenna that can hear DX and non directional beacons around 300 kHz.

It's an interesting challenge on two fronts. First it has too look good for indoor use so two separate boxes and ethernet cable connection were out and it has to have some form of flat mount to fit on a table. All the amplifier and power filtering was fitted into what would usually be the head unit and I sourced a rather nice oak plinth usually used for making trophies as a base.

The second challenge was even tougher. The standard loop antenna we make at present rolls off at 500 kHz. I used a revised circuit made for another "special" loop antenna but changed the biasing arrangement so that it would work better at low frequencies. I overdid it a bit as I can now hear the VLF submarine transmission from the Anthorn radio station in north west England on 22.1 kHz with the loop. To allow it to be used indoors I added a common mode filter to the antenna input to stop the loop acting as an electric field probe picking up RF noise from the house electrical system. I adder extra common mode filters to the DC input and RF output to further isolate the antenna from noise.

Testing it on HF shows that it will receive DX as ordered. Yesterday evening I was doing comparison tests with a Terminated Inverted U antenna (the lowest noise antenna here so far) on the 80m amateur band and the loop out-performed it even though it was mounted indoors next to two computers.

The improved loop amplifier design is now going to be added to the existing HF Active Loop antenna extending the frequency coverage from 20 kHz to 70 MHz with a dipole loop pattern and multilobe pattern up to 148 MHz.

Unfortunately the indoor version is likely to remain a one-off as I can no longer source a RF quiet linear 12V power supply due to EU regulations outlawing them replacing them with switch mode power supplies in the quest for power efficiency. Every switch mode power supply I've tried generates too much noise even with the common mode filters added to the antenna amplifier. I'm supplying the last of my stock of linear power supplies with it.

Here are some photos of the antenna taken today before it's delivered to the customer tomorrow.

<Indoor_active_loop1.jpg><Indoor_active_loop2.jpg>

Regards,

Chris


One-off special...Indoor HF Active Loop antenna

Chris Moulding
 

Sometimes we are asked to do one-off versions of our products for special applications, very often it helps push the development of our products into new areas.

Recently I was asked by a short wave listener who only lives a few miles from us if we could build an indoor version of our HF Active Loop antenna. It's not possible for him to erect outdoor antennas but he still wants an antenna that can hear DX and non directional beacons around 300 kHz.

It's an interesting challenge on two fronts. First it has too look good for indoor use so two separate boxes and ethernet cable connection were out and it has to have some form of flat mount to fit on a table. All the amplifier and power filtering was fitted into what would usually be the head unit and I sourced a rather nice oak plinth usually used for making trophies as a base.

The second challenge was even tougher. The standard loop antenna we make at present rolls off at 500 kHz. I used a revised circuit made for another "special" loop antenna but changed the biasing arrangement so that it would work better at low frequencies. I overdid it a bit as I can now hear the VLF submarine transmission from the Anthorn radio station in north west England on 22.1 kHz with the loop. To allow it to be used indoors I added a common mode filter to the antenna input to stop the loop acting as an electric field probe picking up RF noise from the house electrical system. I adder extra common mode filters to the DC input and RF output to further isolate the antenna from noise.

Testing it on HF shows that it will receive DX as ordered. Yesterday evening I was doing comparison tests with a Terminated Inverted U antenna (the lowest noise antenna here so far) on the 80m amateur band and the loop out-performed it even though it was mounted indoors next to two computers.

The improved loop amplifier design is now going to be added to the existing HF Active Loop antenna extending the frequency coverage from 20 kHz to 70 MHz with a dipole loop pattern and multilobe pattern up to 148 MHz.

Unfortunately the indoor version is likely to remain a one-off as I can no longer source a RF quiet linear 12V power supply due to EU regulations outlawing them replacing them with switch mode power supplies in the quest for power efficiency. Every switch mode power supply I've tried generates too much noise even with the common mode filters added to the antenna amplifier. I'm supplying the last of my stock of linear power supplies with it.

Here are some photos of the antenna taken today before it's delivered to the customer tomorrow.



Regards,

Chris


New versions of the Receiver front end protection unit

Chris Moulding
 

Following customer feedback we now make two versions of our Receiver front end protection unit.

A new VHF version covering 30 to 300 MHz is now available and the frequency range of the original version has been extended LF so that it now covers 50 kHz to 50 MHz as a VLF/HF version.

The other features remain the same, it can take up to 150W, galvanically isolates the receiver from the antenna, divert electrostatic charges to ground and can protect against nearby lightning surges.

The through loss is typically less than 0.5 dB over the frequency band covered.

The web page is:

http://www.crosscountrywireless.net/receiver_protection_unit.htm

Regards,

Chris


Re: APRS Messenger Serial Port Handling - Major Discovery

WA8LMF
 

On 9/9/2018 4:37 AM, Chris Moulding wrote:
Stephen,

Which version of APRS Messenger are you using for this investigation? Is it v3.64 or one of the recent test versions?
it was the standard current release 3.54 .  After all the installs and uninstalls of various versions,  and after TEST2 failed,  I decided to revert to the current production version 3.54. I discovered that it too would also not see ANY ports, even though it had previously.  After considerable teeth-knashing and hair-tearing, I then discovered that the Device Manager settings for baud rate and flow control affected whether Messenger  see any ports at all. Apparently somewhere in this endless series of tests, I had set the Device Manager to the "correct" NMEA  parameter of 4800 baud, and unwittingly "broke" Comm32.ocx .

Although the available COM ports (except for the splitter) are again being seen as available by Messenger, the random lockup after several hours is still happening.

Something still doesn't compute.    While some of the applications I listed only offer 16 or fewer COM number choices (Uiview32 only offers 8), most allow port # up to 254.     Does this mean these other applications are not using MScomm32,  and also not Comm32, but rather yet another com port library of some sort?

At one time, I thought perhaps the flaky hard-to-reproduce COM port problems might be due to  multiple different versions of Comm32 left in different places by other programs.  (I.e. the classic "DLL Hell")            When I did a brute-force search across  multiple entire machines for   "*comm32",  I only found MScomm32.ocx  and a single copy of Comm32.ocx.    The single copy of Comm32.ocx  comes and goes with the install and uninstall of Messenger,  so apparently no other program is using it to extend the range of available com port numbers.


Re: APRS Messenger Serial Port Handling - Major Discovery

Chris Moulding
 

Stephen,

Which version of APRS Messenger are you using for this investigation? Is it v3.64 or one of the recent test versions?

It doesn't surprise me that Comm32 takes note of the default values that other com port routines ignore.  It was written as a complete replacement for Microsoft's MSComm32 which had many problems (a maximum of 16 com ports, odd behavior etc).

It's possible that Comm32 looks at the default values of the com ports when it scans every com port in a loop to generate the com port list on program start up. APRS Messenger does save and use the com port number and data speed selected with Comm32 but that is only sent to Comm32 after the initial search for comm ports.

Regards,

Chris


APRS Messenger Serial Port Handling - Major Discovery

WA8LMF
 

I normally default everything involved with NMEA serial GPS data to 4800 baud, since that is the "official" data rate for the NMEA standard.    (Even though many hardware devices and a log of software offer "9600 baud GPS" modes.)

This includes the settings in the Device Manager.  I have always changed the default 9600 baud setting for serial ports (both real RS232 ports and virtual COM ports created by USB<-->serial drivers) to 4800-8-N-1. I have also selected ""Flow Control: None" in the Device Manager com port settings,  since I am using simple 3-wire serial cables with no RTS/CTS/DTR lines on the physical serial hookups.

Further, I had assumed that the port settings in the Device Manager dialogs are mostly ignored anyway (except for the COM number assignment), since virtually all applications I have ever used override the default settings, and initialize the port control registers with their own preferred settings.      

I have just discovered that setting the Device Manager settings to 9600 baud with "Flow Control: Hardware" makes Messenger see the hardware (physical RS-232 port or USB virtual port)  every time,   EVEN THOUGH I have Messenger defaulting to 4800 baud GPS mode (i.e. don't have the "9600 baud" box on the start screen checked), and am using a simple 3-wire serial cable.     

[No other serial-port-using applications I have tried are affected by the Device Manager settings in any way except for the COM number.    This includes 4 GPS-driven mapping applications, 3 APRS applications, FLdigi and FLrig, mmSSTV, mmTTY, Digipan, MixW, JT-65, COAA BeaconSee, an eprom programmer,  the Chirp radio programming tool, the factory programming tools for my TS-2000, FT-857, FT-891, Kenwood TM-D700, TH-D7, TH-D72 or Wouxun KG-UV8D, etc.  ]  

My new hunch is that there something weird or missing about the initialization values being passed into or out of the COMM32.OCX module on Messenger's  startup.....

I'm now playing around with numerous com port settings in the Eterlogic VSPE port splitter trying to make it findable to Messenger as well.    




Stephen H. Smith    wa8lmf (at) aol.com
Skype:        WA8LMF
EchoLink:  Node #  14400  [Think bottom of the 2-meter band]
Home Page:          http://wa8lmf.net

Live Off-The-Air APRS Activity Maps
   <http://wa8lmf.net/map>

Long-Range APRS on 30 Meters HF
   <http://wa8lmf.net/aprs/HF_APRS_Notes.htm>


Re: Testing thur my station ?

Russell Blair <nc5opsk@...>
 

Ok thanks for the info it seems to work. 

 Russell NC5O



__________________________________
Sent from eM Client | www.emclient.com

------ Original Message ------
From: "ROCKY G WILSON" <rockygwilson@...>
To: "crosscountrywireless@groups.io" <crosscountrywireless@groups.io>
Sent: 9/7/2018 10:25:18 PM
Subject: Re: [CrossCountryWireless] Testing thur my station ?

SMSGTE is an application that allows amateur radio operators to exchange text message between their APRS* radios or clients and SMS (cellular text messages). The gateway is in operation today, however development continues with a focus on reliability, resiliency and deployment flexibility

Rocky  N5MTX





From: Russell Blair
Sent: Friday, September 7, 6:37 PM
Subject: [CrossCountryWireless] Testing thur my station ?
I have been seeing some testing going thur my station (SMSGTE to KF6LMD) and some numbers. Who is SMSGTE ? but it seams to be working for them. Anyone know who is SMSGTE are. Russell NC5O __________________________________ Sent from eM Client | https://eur02.safelinks.protection.outlook.com/?url=www.emclient.com&data=02%7C01%7C%7C3610567787924370054808d6151aeb54%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C636719602684381439&sdata=YSBI4pf8vioHZMadEbaEIWAJqwGq5NkLqgOe%2FAr5Thc%3D&reserved=0


Re: Testing thur my station ?

Neill Thornton
 

The SMS Gateway is ran by Paul Dufresne, VE3OTB.


He has a web page up here:  http://smsgte.wixsite.com/smsgte


His e-mail is prdufresne@...


If you end up using the gateway, please consider dropping a few dollars in his donation bucket as he pays for the service (including the SMS fees) out of his own pocket.


Thanks,


Neill


From: CrossCountryWireless@groups.io <CrossCountryWireless@groups.io> on behalf of Russell Blair <nc5opsk@...>
Sent: Friday, September 7, 2018 4:37:41 PM
To: CrossCountryWireless@groups.io
Subject: [CrossCountryWireless] Testing thur my station ?
 
I have been seeing some testing going thur my station (SMSGTE to KF6LMD)
and some numbers. Who is SMSGTE ? but it seams to be working  for them.
Anyone know who is SMSGTE are.

Russell NC5O



__________________________________
Sent from eM Client | www.emclient.com <http://www.emclient.com/get>





Re: Testing thur my station ?

 

SMSGTE is an application that allows amateur radio operators to exchange text message between their APRS* radios or clients and SMS (cellular text messages). The gateway is in operation today, however development continues with a focus on reliability, resiliency and deployment flexibility

Rocky  N5MTX





From: Russell Blair
Sent: Friday, September 7, 6:37 PM
Subject: [CrossCountryWireless] Testing thur my station ?
To: crosscountrywireless@groups.io


I have been seeing some testing going thur my station (SMSGTE to KF6LMD) and some numbers. Who is SMSGTE ? but it seams to be working for them. Anyone know who is SMSGTE are. Russell NC5O __________________________________ Sent from eM Client | https://eur02.safelinks.protection.outlook.com/?url=www.emclient.com&data=02%7C01%7C%7C3610567787924370054808d6151aeb54%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C636719602684381439&sdata=YSBI4pf8vioHZMadEbaEIWAJqwGq5NkLqgOe%2FAr5Thc%3D&reserved=0


Testing thur my station ?

Russell Blair <nc5opsk@...>
 

I have been seeing some testing going thur my station (SMSGTE to KF6LMD) and some numbers. Who is SMSGTE ? but it seams to be working for them. Anyone know who is SMSGTE are.

Russell NC5O



__________________________________
Sent from eM Client | www.emclient.com <http://www.emclient.com/get>

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