Date   

Re: lOOP cONSTRUCTION

Chris Elmquist
 

OK. Very interesting Chris. I was going to build the loop out of some scrap 1/2" heliax, with the center conductor as the element so I guess instead, I'll just use the shield as the element :-)

Have a lot of the usual noise sources here-- LED bulbs, neighbor's computers, switch mode wall-warts everywhere so was hoping the shielded loop would offer some better immunity to that
junk.

73, Chris N0JCF


Re: lOOP cONSTRUCTION

Chris Moulding
 

Hi Chris,

After a lot more testing of the shielded loop and Mobius loop designs it became clear that they gave no improvement in noise rejection over an unshielded loop.

The design of the Loop Antenna Amplifier in the later "+" and "++" versions gives a tightly balanced loop input that helps reject common mode reception from the loop element. The early HF/VHF version also had a similar input design.

In all versions of the Loop Antenna Amplifier there is a common mode filter on the coax output to reject common mode noise coming up the feeder to the loop element.

I suspect that it was the common mode noise coming up the feeder that made the shielded and Mobius designs appear to have lower noise in amplifiers that didn't have good common mode rejection.

It's far better to stop the noise before it can reach the loop antenna element.

Regards,

Chris


Re: lOOP cONSTRUCTION

Chris Elmquist
 

Chris,

I too would like to build a shielded loop with your Loop Antenna Amplifier. Wondering if the photos or drawings of what yours is like have made it up somewhere since this posting?

Thanks so much,

73,
Another Chris N0JCF


Re: SDR-4 Special Edition and W10

Angel Mateu
 

Hi Chris:

 

Many tnx for your quick responce.

 

Tomorrow I buy my SDR-4

 

Tnx

Angel.

 

EA4GIG

 

De: CrossCountryWireless@groups.io <CrossCountryWireless@groups.io> En nombre de Chris Moulding
Enviado el: jueves, 3 de junio de 2021 20:10
Para: CrossCountryWireless@groups.io
Asunto: Re: [CrossCountryWireless] SDR-4 Special Edition and W10

 

Hi Angel,

The soundcard in the SDR-4+ Special Edition is a generic USB soundcard that will work with all versions of Windows including Windows 10.

The driver for the frequency control can be downloaded from this web page https://pe0fko.nl/SR-V9-Si570/#install

Scroll down until you find "Install the PC driver software automatic".

Download the program "PE0FKO-USB-Driver-Installer.exe". Install this program and it will automatically load the driver and certificate to work in Windows 10.

Once the driver is installed I would recommend using the HDSDR program, I was always my favourite SDR program with the SDR-4+.

Regards,

Chris


Re: SDR-4 Special Edition and W10

Chris Moulding
 

Hi Angel,

The soundcard in the SDR-4+ Special Edition is a generic USB soundcard that will work with all versions of Windows including Windows 10.

The driver for the frequency control can be downloaded from this web page https://pe0fko.nl/SR-V9-Si570/#install

Scroll down until you find "Install the PC driver software automatic".

Download the program "PE0FKO-USB-Driver-Installer.exe". Install this program and it will automatically load the driver and certificate to work in Windows 10.

Once the driver is installed I would recommend using the HDSDR program, I was always my favourite SDR program with the SDR-4+.

Regards,

Chris


SDR-4 Special Edition and W10

Angel Mateu
 

Hello I am new to the group.

 

 

I'm thinking of buying a second-hand SDR-4 Special Editions, and I don't know if the drivers are compatible with Windows 10 ???.

 

Some help please.

 

Thank you

 

Angel.


Re: New version of Receiver Protection Unit

Chris Moulding
 

OK it's official.

SDRPlay have approved the VLF/HF Receiver Protection Unit as recommended for use below 50 MHz with SDRPlay RSP receivers.

I've added the change to the web page:

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

Regards,

Chris


New version of Receiver Protection Unit

Chris Moulding
 

We have released a new version of the Receiver Protection Unit so that the maximum output is below the strict 10 dBm limit for SDRPlay receivers.

In the previous version the maximum output level was 17 dBm which is OK for the majority of receivers but was still too high for SDRPlay receivers.

The protection unit uses a range of methods such as a gas discharge tube, isolation transformer and cascaded diode limiters to bring excessive RF power down to a safe level.

If connected to a ground it will also drain static electricity from the antenna and a 10 kA gas discharge tube will help with nearby lightning strikes.

With the latest version you could connect a 150 W transmitter for that ham radio "Oops!" moment without exceeding the SDRPlay receiver limit.

More details on the web page: http://www.crosscountrywireless.net/receiver_protection_unit.htm

Regards,

Chris


Re: Loop Aerial amplifier power module C3

Stephen Farthing
 

Chris,

Thanks for the prompt and fulsome response. 

Stay safe,

Steve G0XAR 

On Mon, 17 May 2021 at 19:19, Chris Moulding <chrism@...> wrote:
Hi Steve,

You can replace the SMD capacitor with a through hole version.

The value is 10 uF and the positive terminal of the capacitor goes to the left when you hold the board so that you can read the text on the PCB.

Regards,

Chris


Re: Loop Aerial amplifier power module C3

Chris Moulding
 

Hi Steve,

You can replace the SMD capacitor with a through hole version.

The value is 10 uF and the positive terminal of the capacitor goes to the left when you hold the board so that you can read the text on the PCB.

Regards,

Chris


Loop Aerial amplifier power module C3

Stephen Farthing
 

Chris, 

C3 from the power module board just fell off (see the picture attached). I’ve recovered it but resoldering it is going to be a challenge for me as it’s an SMT part without much in the way of leads. I’ve some leaded tantalum and electrolytic capacitors of the same working voltage and value. Is there any reason why I shouldn’t substitute a leaded component ? 

Regards, 

Steve G0XAR 


Re: The case of the mysterious Multicoupler...

Simon
 

Hi was mine..as was the yaesu ftdx101

Thank you..






Not really..

Simon g0zen


The case of the mysterious Multicoupler...

Chris Moulding
 

Last week we received a HF/VHF/UHF Multicoupler in the post.

Unfortunately there was no letter or note included to say who it was from or why it was sent back.

The only clue I have is that it was posted in the UK with a printed post label with no post mark.

Can the owner please contact me (by email if you want to avoid embarrassment) so that we can solve this case?

Regards,

Chris


Re: VLF/LF/HF Active Vertical Antenna...5 kHz to 30 MHz Discontinued!

Chris Moulding
 

Yes, the revised design for the Broadband Active Antenna will be powered by 5 V so it will be suitable for use with the bias tee in SDRPlay receivers.

An option will be added at the same time for the Multicoupler so that it can act as a bias tee powering a Broadband Active Antenna via the coax feeder.

Regards,

Chris


Re: VLF/LF/HF Active Vertical Antenna...5 kHz to 30 MHz Discontinued!

Scott
 

Great to hear Chris.

Is the intention still to add a bias T power option to the broadband antenna? And an output on the multicoupler to match?

Thanks 


On Thu, May 6, 2021 at 05:04 AM, Chris Moulding wrote:
The plan as we come out of lockdown in the UK is to start making batches of some of the products paused during the lockdown.

The first will be a Vee antenna amplifier later this week. We will not make the full Vee antenna with whips, brackets, expensive shipping price etc but a small amplifier with a Stauff clamp so that customers can source the antenna whips locally to fit it on their own antenna mast.

The next three products not in any order will be the HF Preselector, Broadband Active Antenna and the VLF/LF/HF Active Vertical antenna.

The timing of the batches and what is built first will depend upon when all components are available. I'm trying to source all components this week so that we can get started. It's surprising what things have been affected by the Covid-19 lockdown and the semiconductor shortage.

Regards,

Chris


Re: VLF/LF/HF Active Vertical Antenna...5 kHz to 30 MHz Discontinued!

Chris Moulding
 

The plan as we come out of lockdown in the UK is to start making batches of some of the products paused during the lockdown.

The first will be a Vee antenna amplifier later this week. We will not make the full Vee antenna with whips, brackets, expensive shipping price etc but a small amplifier with a Stauff clamp so that customers can source the antenna whips locally to fit it on their own antenna mast.

The next three products not in any order will be the HF Preselector, Broadband Active Antenna and the VLF/LF/HF Active Vertical antenna.

The timing of the batches and what is built first will depend upon when all components are available. I'm trying to source all components this week so that we can get started. It's surprising what things have been affected by the Covid-19 lockdown and the semiconductor shortage.

Regards,

Chris


Re: VLF/LF/HF Active Vertical Antenna...5 kHz to 30 MHz Discontinued!

Stephen
 

Hello Chris

As we emerge from lockdown, do you still have plans for a new batch of the VLF/LF/HF Active Vertical Antenna...5 kHz to 30 MHz ?

Kind regards

Stephen


WA8LMF APRS Webserver Connections Upgraded To Far Higher Speed

WA8LMF
 

For years, my home APRS Webservers have been running on a Comcast cable modem Internet connection  that barely yielded a 500Kb/sec upload speed.

As of 1 May 2021, these servers are now using a 100 Mb/sec up/down fiber Internet connection.  People viewing maps generated by the 11 copies of Uiview running on this server should now experience vastly faster load times than before. 

The WA8LMF UIwebserver runs on an Acer E3-111 "netbook" 11.8" "mini-laptop" running Win7-64 supporting 4 VMware virtual machines.

This netbook uses a quad-core Pentium processor with 8GB RAM and a 1TB SSD.  Total power draw is 9.5 watts while supporting 11 copies of UIiview, BeaconSee (IARU beacon monitor), EchoLink and two SSTV automatic receive systems.  It provides real-time views of what I am hearing off-the-air  (not the Internet) in central MIchigan,  on 144.39 MHz VHF, the ISS APRS digipeater on 145.825 MHz, 30 Meters HF and 60 Meters HF.   The HF systems map both classic AS.25 packet APRS and PSK63/MFSK16 APRS reception on separate instances of UIview; i.e. 4 separate copies.   As before

    <http://WA8LMF.net/map>

is the gateway page leading to all these mapping displays.


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

-- APRS over FLdigi Modes  --
   <http://wa8lmf.net//FLdigiAPRS/index.htm>

60-Meter APRS!   HF NVIS APRS Igate Now Operating
   <http://wa8lmf.ddns.net:14447/>

Flying Digipeater!
   <http://WA8LMF.net/FlyingDigi>

 


Re: Ccw cardioid loop..update from a user of..

Chris Moulding
 

The Loop Antenna Amplifier + is designed to match a small loop around 0.7 to 2m diameter.

The cardioid loop presents an impedance that equals the loop impedance plus the terminating resistor.

A 1m diameter cardioid loop with a 110 ohm terminating resistor is at the high end of what the Loop Antenna Amplifier + (LAA+) can work with but it works OK.

A larger 2m diameter cardioid loop with a 470 ohm termination resistor doesn't match to the LAA+. It works but the output is low due to the mismatch.

The larger loop needs a 4:1 transformer to match the LAA+. The Beverage Antenna Amplifier has a 4:1 transformer built in and works perfectly with the 2m diameter cardioid loop.

Regards,

Chris


Re: Ccw cardioid loop..update from a user of..

Tom Seeger
 

Thanks Simon. But I thought that the 1m loop could connect directly to the LAA+ without a transformer. At least according to Chris's guide.
http://www.crosscountrywireless.net/cardioid_loop_antenna.htm
Are you saying it will work better with a 4:1 balun?
Tom

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