Covid..and making phased loop antenna array..


Simon
 

First of all happy new year to all..

my wife  and I are recovering from covid..mother in law is in hospital..induced coma..so lets say DONT get this!! Its not good..fingers crossed for m in law..
It took out 50% of staff at work..all much younger than I. So please be careful.

so had 2 plus weeks of not alot I can do ..cant leave house..( track and trace.) 
this may be of interest to you active loop lot! ( or not.)

have been making a phased loop array ..aim is to be able to hear usa etc on 160m in one direction..(nw) Australia in another etc..

as you know dought know the single loop has a pretty poor angle of max take off..ie vertical..

to improve this Chris has posted design for the cardioid loop..this however I have found is “ deaf” at my qth. I need much much more “gain “ to hear usa on 160m ssb..

so have built 2 of 4 square 1 m crossed loop arrays..to be placed inline at 8m apart ( max I can get.)  these are running into a pair of high gain high imd preamps..then into a passive variable delay line..then into rx..cat5e cable though out.
(there will be a third made to have 4 directions, but for now just 2.)

reason have used such a large loop array is that it has about 16 times current going to amp than a single 1m loop..( 1/4,inductance plus 4 times area.) this helps no end and compensates for the 6db loss in the  delay line/ combiner..

The advantages of this phased array hopefully will be once finished , 4 switchable directions..good front  to back ratio..and much much lower angle of radiation angle..ie dx..

disadvantage..Chris has not made a passive delay line!! So had to build it all in house= many days..( still got sod all else to do..cant visit m in law..got covid plus no visitors..another plus is dont have to watch day time tv!! ( god its crap!!)

so now to “ hide” two big loops..thinking i will hide them in full view..and see whats said..

hopefully testing tomorrow..

stay well mag loop simon g0zen 



Tom Crosbie G6PZZ
 

Simon,

Really sorry to hear of you medical misfortune. It’s great to see you’ve still got the energy for construction, experimenting, plumbing, whatever you call it. You are an example to us all.

I look forward to the recovery of all your family and the results of your latest creation.

We’re going through our own medical issues here so my thoughts are with you.

Tom G6PZZ

 

From: CrossCountryWireless@groups.io <CrossCountryWireless@groups.io> On Behalf Of Simon
Sent: 01 January 2021 18:31
To: CrossCountryWireless@groups.io
Subject: [CrossCountryWireless] Covid..and making phased loop antenna array..

 

First of all happy new year to all..

my wife  and I are recovering from covid..mother in law is in hospital..induced coma..so lets say DONT get this!! Its not good..fingers crossed for m in law..
It took out 50% of staff at work..all much younger than I. So please be careful.

so had 2 plus weeks of not alot I can do ..cant leave house..( track and trace.) 
this may be of interest to you active loop lot! ( or not.)

have been making a phased loop array ..aim is to be able to hear usa etc on 160m in one direction..(nw) Australia in another etc..

as you know dought know the single loop has a pretty poor angle of max take off..ie vertical..

to improve this Chris has posted design for the cardioid loop..this however I have found is “ deaf” at my qth. I need much much more “gain “ to hear usa on 160m ssb..

so have built 2 of 4 square 1 m crossed loop arrays..to be placed inline at 8m apart ( max I can get.)  these are running into a pair of high gain high imd preamps..then into a passive variable delay line..then into rx..cat5e cable though out.
(there will be a third made to have 4 directions, but for now just 2.)

reason have used such a large loop array is that it has about 16 times current going to amp than a single 1m loop..( 1/4,inductance plus 4 times area.) this helps no end and compensates for the 6db loss in the  delay line/ combiner..

The advantages of this phased array hopefully will be once finished , 4 switchable directions..good front  to back ratio..and much much lower angle of radiation angle..ie dx..

disadvantage..Chris has not made a passive delay line!! So had to build it all in house= many days..( still got sod all else to do..cant visit m in law..got covid plus no visitors..another plus is dont have to watch day time tv!! ( god its crap!!)

so now to “ hide” two big loops..thinking i will hide them in full view..and see whats said..

hopefully testing tomorrow..

stay well mag loop simon g0zen 


Simon
 

Hi Tom

Thanks for your wishes..

I hope Whatever you may be going though gets better soon..not been a good year!! ( worse for mother in law, but imagine mrs browns boys..well she is mrs brown’s mum..one thing is for sure is that she will not give up! )

Let you know how steerable loop array goes..

Simon


Tom Seeger
 

Simon, I hope your mother in-law has a full recovery soon. I'm impressed with your energy under the circumstances. Just wondering if you have tried any other directional RX antennas? I've heard good things about the K9AY, EWE, superloop and KAZ. I have not tried any of those myself yet. But am planning to this spring. Regards Tom VE3PSZ


David Cutter
 

QST March 2015 by  DK6ED may be of interest and shows 4 fixed loops in an array, alongside a small rotatable array. 

The rotatable array looks relatively straight forward to build and his personal web site has more up to date detail on that. 

https://www.qsl.net/dk6ed/

It would be interesting to know if one of Chris's amplifiers would do the job for this.

David G3UNA


On 01 January 2021 at 19:15 Tom Crosbie G6PZZ <tom@...> wrote:

Simon,

Really sorry to hear of you medical misfortune. It’s great to see you’ve still got the energy for construction, experimenting, plumbing, whatever you call it. You are an example to us all.

I look forward to the recovery of all your family and the results of your latest creation.

We’re going through our own medical issues here so my thoughts are with you.

Tom G6PZZ

 

From: CrossCountryWireless@groups.io <CrossCountryWireless@groups.io> On Behalf Of Simon
Sent: 01 January 2021 18:31
To: CrossCountryWireless@groups.io
Subject: [CrossCountryWireless] Covid..and making phased loop antenna array..

 

First of all happy new year to all..

my wife  and I are recovering from covid..mother in law is in hospital..induced coma..so lets say DONT get this!! Its not good..fingers crossed for m in law..
It took out 50% of staff at work..all much younger than I. So please be careful.

so had 2 plus weeks of not alot I can do ..cant leave house..( track and trace.) 
this may be of interest to you active loop lot! ( or not.)

have been making a phased loop array ..aim is to be able to hear usa etc on 160m in one direction..(nw) Australia in another etc..

as you know dought know the single loop has a pretty poor angle of max take off..ie vertical..

to improve this Chris has posted design for the cardioid loop..this however I have found is “ deaf” at my qth. I need much much more “gain “ to hear usa on 160m ssb..

so have built 2 of 4 square 1 m crossed loop arrays..to be placed inline at 8m apart ( max I can get.)  these are running into a pair of high gain high imd preamps..then into a passive variable delay line..then into rx..cat5e cable though out.
(there will be a third made to have 4 directions, but for now just 2.)

reason have used such a large loop array is that it has about 16 times current going to amp than a single 1m loop..( 1/4,inductance plus 4 times area.) this helps no end and compensates for the 6db loss in the  delay line/ combiner..

The advantages of this phased array hopefully will be once finished , 4 switchable directions..good front  to back ratio..and much much lower angle of radiation angle..ie dx..

disadvantage..Chris has not made a passive delay line!! So had to build it all in house= many days..( still got sod all else to do..cant visit m in law..got covid plus no visitors..another plus is dont have to watch day time tv!! ( god its crap!!)

so now to “ hide” two big loops..thinking i will hide them in full view..and see whats said..

hopefully testing tomorrow..

stay well mag loop simon g0zen 

 



 


 


Simon
 

Hi Tom

Real estate is my issue here in london..I have none!!

All this is to be done in 8x8m area..( ish.)

Tried the ewe..log etc all no go here..

The loops HERE in my high noise urban london qth work by far the best..( apart from the mag loop.)


I would like to try flags but just no room. Hence why i use a big mag loop for tx.( and rx.) .gets me across the pond on 160m ssb .granted not as good as a 80m high dipole but it does work..( actually better than most over here in the uk as most have silly low short dipoles, again due to space issues.)

Anyway..hopefully trying the array out today..rain ( its england.) allowing..( dont need to get any more ill!)


Simon
 

Hi
Dave

Yes have seen this..done ALOT of research on active small dx low band antennas..

I dont have the room..so not gone into it too far..

Its very easy to build a preamp though..

Best you ask Chris yourself about his preamp..


Chris Moulding
 

The Loop Antenna Amplifier + would be a good match with the DK6ED loops and loop array.

Another antenna to add to my testing wish list!

Too many antennas, not enough time (or space)!

Regards,

Chris


Sean - G4UCJ
 

Hi Chris,

Just a note of thanks for the incredibly speedy delivery of the loop amplifier. Considering that New Year was in the way, I'm amazed that RM got it to me in well under a week.

 

The fun will begin, hopefully, tomorrow when the amp is installed onto the Wellbrook aluminium loop. Just going back through emails to see if there are any further nuggets of useful info I can extract in relation to installation and my intended usage.

 

I'm looking forward to getting the loop working again so I can phase it with the other CCW loop (the delta shaped one) using my MFJ1026 (since checking some videos I have found it has been modified to give coverage of MW and what appears to be an increased phasing range via a second switch).

 

Now, if the weather plays ball, I can start this tomorrow. Even managed to find a suitable box to house the bias T board :)

 

There are some images of the loop set up on my website (recently updated) www.hfradio.org.uk

 

73, Sean G4UCJ

 

From: CrossCountryWireless@groups.io [mailto:CrossCountryWireless@groups.io] On Behalf Of Chris Moulding
Sent: Saturday, January 2, 2021 11:52 AM
To: CrossCountryWireless@groups.io
Subject: Re: [CrossCountryWireless] Covid..and making phased loop antenna array..

 

The Loop Antenna Amplifier + would be a good match with the DK6ED loops and loop array.

Another antenna to add to my testing wish list!

Too many antennas, not enough time (or space)!

Regards,

Chris


Simon
 

Well it’s working..

20 plus db front to back ratio..possibly 25..

stunning..

issue have is now need to move both active loops to front of garden as far too close to mag loop.
they couple to mag loop..All fine if mag loop not on same frequency, but if same ( and obviously it needs to be!) i lose f/ b ratio..

bugger..2 days wasted..and how to hide a 2x2 m square loop antenna in front of house!!??

pics of loops in situ..shame cant stay there...s3 noise on 160m carlos in italy 20 over..or s7...depending upon loop direction..


David Cutter
 

Great work, Simon.  I'm sure a lot of folks will be interested.

David G3UNA

On 04 January 2021 at 01:10 Simon <ohhellnotagain@...> wrote:

Well it’s working..

20 plus db front to back ratio..possibly 25..

stunning..

issue have is now need to move both active loops to front of garden as far too close to mag loop.
they couple to mag loop..All fine if mag loop not on same frequency, but if same ( and obviously it needs to be!) i lose f/ b ratio..

bugger..2 days wasted..and how to hide a 2x2 m square loop antenna in front of house!!??

pics of loops in situ..shame cant stay there...s3 noise on 160m carlos in italy 20 over..or s7...depending upon loop direction..


Simon
 

Hello

Updates..

Maybe big mag loop is not coupling as much as had feared..going to leave rx loops in situ for today and test properly this eve...if they do couple then tomorrow move them lower and behind garage..giving them another 3m spacing from big loop..
Ideally i would like to put one in Neighbours garden..!! ( to be worked on!)

Regarding cat5e vs coax..( feeding the loops, delay line etc.)

Lets say will be replacing the coax to my other active rx loops asap!
Common mode noise non existent upon the cat5e setup..ie turn power off to loops..and noise floor on my duo sdr is at circa -140...ie rx noise floor.( loops still connected, just not powered up.)

To get near that using coax ( as on other rx loop) i have needed to add ALOT of ferrite..and its still no way as “ clean”.
Another advantage of the cat5e is one has 4 pairs to play with..which can be used to control switched loops etc.
Another advantage is its cheap compared to decent coax.

Lets see how loops cope this eve when 160 open..

Simon


paul newland
 

Hi Simon
Having read your remarks regarding cat5e, being somewhat above of ignorant with respect to cabling, but with RG58 (some ageing) in use by me, should I get around to replacing it, this does sound vey attractive.
Kind Regards
Paul


David Cutter
 

CCW have been using Cat5 for many years.  It is also endorsed by Jim Brown K9YC, something of a guru.  

David G3UNA

On 04 January 2021 at 13:55 "paul newland via groups.io" <p.newland@...> wrote:

Hi Simon
Having read your remarks regarding cat5e, being somewhat above of ignorant with respect to cabling, but with RG58 (some ageing) in use by me, should I get around to replacing it, this does sound vey attractive.
Kind Regards
Paul


Simon
 

Hi Paul

Yes and no..

Cat5 has 100r impedance..so one has to alter output transformer on preamp ( if designed for 50r.)
Also at bias tee one needs an isolation transformer 100r to 50r to connect to rx. Thats if you want to do it properly..plus send power up another twisted pair ( 4 twisted pairs in cat5e.)

Chris I know made stuff using cat5 but ( i may be mistaken here!) it “put people off” as takes abit more work..???

However the end results are worth the effort..

High end cctv all use cat5e or similar cable..not coax..( unless running wireless.) the same reason they use it applies to us.ie low loss..balanced feeder..zero to very low common mode interference AND ITS cheaper!

The best tx feeder is open wire balanced ..same principle but MUCH harder to implement ( hence why coax is so popular..) ie feeding though a wall etc..

If you suffer from common mode interference on your rx loop/s, then i would recommend working out how to fit cat5e..( screened.. solid copper..uv resilient ( outside grade.))

One can buy mini transformers 100r cat5e to 50r bnc ..designed for cctv..easy fit..BUT i have no idea of frequency range of said devices..

Also..one has to use a seperate twisted pair in cat5e to run power..you do not share rf twisted pair with the power..ie example..rf orange plus orange/white.
12v green plus green/ white..
12v supply has to be feed via comon mode choke at feed and at preamp..( chokes will do at preamp.) circa 100uh..

Sounds complicated but not once get head around it..

Simon


Paul Newland
 

Hello Simon
Thanks for taking the trouble and time to reply to my question Simon. The answer was straight out, and to be honest made me realise that it's " a bit out of my league,"  (I don't have the background, knowledge or self-confidence to give it a go). I'll have to keep life simple, but I wish you every success with your current project, neighbour and full recovery.
Best Wishes
Paul



Virus-free. www.avast.com


On Mon, 4 Jan 2021 at 14:32, Simon <ohhellnotagain@...> wrote:
Hi Paul

Yes and no..

Cat5 has 100r impedance..so one has to alter output transformer on preamp ( if designed for 50r.)
Also at bias tee one needs an isolation transformer 100r to 50r to connect to rx.  Thats if you want to do it properly..plus send power up another twisted pair ( 4 twisted pairs in cat5e.)

Chris I know made stuff using cat5 but ( i may be mistaken here!) it “put people off” as takes abit more work..???

However the end results are worth the effort..

High end cctv all use cat5e or similar cable..not coax..( unless running wireless.) the same reason they use it applies to us.ie low loss..balanced feeder..zero to very low common mode interference AND ITS  cheaper!

The best tx feeder is open wire balanced ..same principle but MUCH harder to implement ( hence why coax is so popular..) ie feeding though a wall etc..

If you suffer from common mode interference on your rx loop/s, then i would recommend working out how to fit cat5e..( screened.. solid copper..uv resilient ( outside grade.))

One can buy mini transformers 100r cat5e to 50r bnc ..designed for cctv..easy fit..BUT  i have no idea of frequency range of said devices..

Also..one has to use a seperate twisted pair in cat5e to run power..you do not share rf twisted pair with the power..ie example..rf orange plus orange/white.
12v green plus green/ white..
12v supply has to be feed via comon mode choke at feed and at preamp..( chokes will do at preamp.) circa 100uh..

Sounds complicated but not once get head around it..

Simon







Tom Crosbie G6PZZ
 

Disguise antenna using something like a net curtain. Paint on…

 

SUPPORTING

NHS

 

Surely no one would object to this?

I don’t mean this to sound flippant in view of you last mail to me. Left me speechless.

Take care

 

Tom

 

From: CrossCountryWireless@groups.io <CrossCountryWireless@groups.io> On Behalf Of Simon
Sent: 04 January 2021 01:10
To: CrossCountryWireless@groups.io
Subject: Re: [CrossCountryWireless] Covid..and making phased loop antenna array..

 

Well it’s working..

20 plus db front to back ratio..possibly 25..

stunning..

issue have is now need to move both active loops to front of garden as far too close to mag loop.
they couple to mag loop..All fine if mag loop not on same frequency, but if same ( and obviously it needs to be!) i lose f/ b ratio..

bugger..2 days wasted..and how to hide a 2x2 m square loop antenna in front of house!!??

pics of loops in situ..shame cant stay there...s3 noise on 160m carlos in italy 20 over..or s7...depending upon loop direction..


Simon
 

Hi Tom

Neighbours and jobs worth council people ( in uniforms telling me to take down my antennas, on their own back without realising they had been up for over 4 years, so had to go away with tail between their legs types..) are funny people..

I get on really well with my neighbours, but sometimes I even think looking up at the antennas that maybe i ought not to put more up!! Lol

Still..i do not live in a conservation area..there are many phone masts within sight much much bigger than anything here..and bird boxes are about to be attached to new loops..lol ( really useful once occupied.)

Hopefully neighbour will allow loop into their back garden ( placed against fence and disguised..)
This will allow it to work better as well as lowering profile..
They owe us some favours so lets see..( Bangladesh family whom only us would speak to for a few years..sorted their kids schools out etc..) very nice people..

Keep well Tom and others. mag loop simon g0zen


Chris Moulding
 

As David commented earlier we have been making active antennas using Cat5 for quite a few years.

As Simon has already found it has some very useful properties for HF use.

Cat 5 cable is a very elegant engineering solution consisting of four two wire 100 ohm impedance twisted pairs. The twist rate of each pair is slightly different to reduce the coupling between each pair.

The cable specification says better than 40 dB isolation between the pairs, in tests we measured over 50 dB. We also found that the unshielded version of the cable was better than the shielded for HF radio use with better isolation and lower loss.

In the active antennas we manufactured two pairs were used for DC power feed, one pair was used for RF and the fourth pair was spare or used for a second RF channel in the case of the Dual Polarisation HF Active Antenna. The secret to getting the best out of Cat5 cable was to correctly terminate each pair at both ends.

At present I'm looking at designing a very high performance loop antenna amplifier. The original Loop Antenna Amplifier was originally meant to be a better low cost alternative to the MLA-30 but due to customer pressure I improved it to become comparable in performance to the Wellbrook and Bonito antenna amplifiers.

With the new design I'm starting from scratch using the best amplifier devices, filtering, weatherproofing and Cat5 interconnecting cable. The first prototype is running with the expected performance improvements. I expect to have the first batch ready in a month or two.

Regards,

Chris


Paul Newland
 

That's going to make the fur fly around here Chris!
Best Wishes
Paul



Virus-free. www.avast.com


On Mon, 4 Jan 2021 at 16:25, Chris Moulding <chrism@...> wrote:
As David commented earlier we have been making active antennas using Cat5 for quite a few years.

As Simon has already found it has some very useful properties for HF use.

Cat 5 cable is a very elegant engineering solution consisting of four two wire 100 ohm impedance twisted pairs. The twist rate of each pair is slightly different to reduce the coupling between each pair.

The cable specification says better than 40 dB isolation between the pairs, in tests we measured over 50 dB. We also found that the unshielded version of the cable was better than the shielded for HF radio use with better isolation and lower loss.

In the active antennas we manufactured two pairs were used for DC power feed, one pair was used for RF and the fourth pair was spare or used for a second RF channel in the case of the Dual Polarisation HF Active Antenna. The secret to getting the best out of Cat5 cable was to correctly terminate each pair at both ends.

At present I'm looking at designing a very high performance loop antenna amplifier. The original Loop Antenna Amplifier was originally meant to be a better low cost alternative to the MLA-30 but due to customer pressure I improved it to become comparable in performance to the Wellbrook and Bonito antenna amplifiers.

With the new design I'm starting from scratch using the best amplifier devices, filtering, weatherproofing and Cat5 interconnecting cable. The first prototype is running with the expected performance improvements. I expect to have the first batch ready in a month or two.

Regards,

Chris