Date   

Re: Horn antenna for EME

Chris Bartram G4DGU
 

Alan,

The guy who designed that horn almost certainly had the length chosen for him by the physics. Waveguide feeding a horn often has to allow the EM wave to establish itself properly with the correct phase and amplitude relationships before performing the transition to free space.

There's no free lunch.

I've designed horn antennas for (10GHz) EME from first principles and they are not simple structures to get right. EME on the microwave bands is very unforgiving of apparently minor problems.

Kent has a lot of professional experience as an antenna designer, and he knows what he's talking about!

73

Chris

G4DGU

On 26/01/2020 21:10, Alan Beard wrote:
Hi Kent,


NO NO NO, I want to feed a horn with four patches.

Or, four crossed dipoles, so the horn doesn't need to be so long.

And also needed is circular polarisation both RH and LH for EME.

Alan VK2ZIW


On Sun, 26 Jan 2020 12:25:32 +0000 (UTC), KENT BRITAIN wrote

> Very difficult to feed a horn with a patch.  Typically the dimensions of the
> patch are far larger than the dimensions of the waveguide.
>
> Yes, you can do optional polarization and even optional feed impedance.
>
> Here is one for 2.4 GHz that is a popular Q-100 dish feed.
> Originally designed for commercial drone video feeds, when placed in a
> radome the impedance of the antenna changed.  So the 'HI' impedance
> attach points allow for the effects of the radome.
>
> Nice big ground plane to attach the shield of the coax too, that decouples
> the feed line nicely.    Kent WA5VJB/G8EMY
>
> test
>
>
€11.00
>

test


> test

>
> On Sunday, January 26, 2020, 4:56:34 AM CST, Alan Beard <beardal@...> wrote:
>
> Perhaps you've seen:
>
> http://ok2kkw.com/next/horn_23cm.pdf
>
> To reduce the horn length, can we cut it in half and feed it with
>
> say four patch antennae?
>
> Or four crossed dipoles fed in phase?
>
> Yes more complex to build but the 2.5m length is a problem.
>
> On the subject of patch antenna:
>
> Can we feed it at two places, a chamfered corner patch, to get
>
> right and left circular polarisation?
>
> How does one do a balanced feed to a patch?
>
> ---------------------------------------------------
>
> Alan VK2ZIW
>
> OpenWebMail 2.53
>

---------------------------------------------------
Alan Beard

OpenWebMail 2.53


Re: Horn antenna for EME

KENT BRITAIN
 

That's not really a horn but more of a broad corner or tapered reflector.

Why do you think the horn will not need to be so long?  It's not going to be much shorter
cutting off the back bit.
Size of the opening determines max possible gain and aperture area,
Angles of the sides determines phase error and how much gain you
lose due to phase errors.  I think you will have sidelobes all over the place
especially if you use 4 emitters.

Good luck, Kent








On Sunday, January 26, 2020, 3:10:34 PM CST, Alan Beard <beardal@...> wrote:


Hi Kent,


NO NO NO, I want to feed a horn with four patches.

Or, four crossed dipoles, so the horn doesn't need to be so long.

And also needed is circular polarisation both RH and LH for EME.

Alan VK2ZIW


On Sun, 26 Jan 2020 12:25:32 +0000 (UTC), KENT BRITAIN wrote
> Very difficult to feed a horn with a patch.  Typically the dimensions of the
> patch are far larger than the dimensions of the waveguide.
>
> Yes, you can do optional polarization and even optional feed impedance.
>
> Here is one for 2.4 GHz that is a popular Q-100 dish feed.
> Originally designed for commercial drone video feeds, when placed in a
> radome the impedance of the antenna changed.  So the 'HI' impedance
> attach points allow for the effects of the radome.
>
> Nice big ground plane to attach the shield of the coax too, that decouples
> the feed line nicely.    Kent WA5VJB/G8EMY
>
> test
>
>
€11.00
>

test


> test

>
> On Sunday, January 26, 2020, 4:56:34 AM CST, Alan Beard <beardal@...> wrote:
>
> Perhaps you've seen:
>
> http://ok2kkw.com/next/horn_23cm.pdf
>
> To reduce the horn length, can we cut it in half and feed it with
>
> say four patch antennae?
>
> Or four crossed dipoles fed in phase?
>
> Yes more complex to build but the 2.5m length is a problem.
>
> On the subject of patch antenna:
>
> Can we feed it at two places, a chamfered corner patch, to get
>
> right and left circular polarisation?
>
> How does one do a balanced feed to a patch?
>
> ---------------------------------------------------
>
> Alan VK2ZIW
>
> OpenWebMail 2.53
>

---------------------------------------------------
Alan Beard

OpenWebMail 2.53


Re: WTB: HP 5086-7781 YIG module

Alan
 

Conrad,

Have seen YIG oscillators go unstable with excessive supply voltage, as your output power is a little high the supply voltage is worth checking.

 

73

Alan

G8LCO

 

Sent from Mail for Windows 10

 

 


Re: Horn antenna for EME

Alan Beard
 

Hi Kent,


NO NO NO, I want to feed a horn with four patches.

Or, four crossed dipoles, so the horn doesn't need to be so long.

And also needed is circular polarisation both RH and LH for EME.

Alan VK2ZIW


On Sun, 26 Jan 2020 12:25:32 +0000 (UTC), KENT BRITAIN wrote

> Very difficult to feed a horn with a patch.  Typically the dimensions of the
> patch are far larger than the dimensions of the waveguide.
>
> Yes, you can do optional polarization and even optional feed impedance.
>
> Here is one for 2.4 GHz that is a popular Q-100 dish feed.
> Originally designed for commercial drone video feeds, when placed in a
> radome the impedance of the antenna changed.  So the 'HI' impedance
> attach points allow for the effects of the radome.
>
> Nice big ground plane to attach the shield of the coax too, that decouples
> the feed line nicely.    Kent WA5VJB/G8EMY
>
> test
>
>
€11.00
>

test


> test

>
> On Sunday, January 26, 2020, 4:56:34 AM CST, Alan Beard <beardal@...> wrote:
>
> Perhaps you've seen:
>
> http://ok2kkw.com/next/horn_23cm.pdf
>
> To reduce the horn length, can we cut it in half and feed it with
>
> say four patch antennae?
>
> Or four crossed dipoles fed in phase?
>
> Yes more complex to build but the 2.5m length is a problem.
>
> On the subject of patch antenna:
>
> Can we feed it at two places, a chamfered corner patch, to get
>
> right and left circular polarisation?
>
> How does one do a balanced feed to a patch?
>
> ---------------------------------------------------
>
> Alan VK2ZIW
>
> OpenWebMail 2.53
>

---------------------------------------------------
Alan Beard

OpenWebMail 2.53


Re: WTB: HP 5086-7781 YIG module

Conrad, PA5Y
 

Hello Chris, sorry I missed this email. I have very little to offer I am afraid.

 

The problems started when I noticed some spurs that started at around 1050MHz, these spurs were only 20dBc or so and rather annoying when making 23cms measurements. So I gave it to a colleague to look at, he is rather gifted at this kind of thing. We noticed that the output from the YIG was rather high and we also noticed that adding a 3dB PAD removed the spurs. I was not happy with this ‘cure’ and so further exploration indicated that the LODA transistor bias was wrong. As soon as the bias pot was moved then all kinds of errors started to appear and we could never get rid of them. So essential we broke it 😊

 

I decided that a replacement or repair was needed. I have sent the YIG for repair as I was unable to find a reasonably priced replacement. I should get an indication of price and indeed if the unit can be repaired some time next week.

 

I have an E4406A that I can use for now but the 10 MHz span is somewhat restrictive, at some point I will buy something more modern as the 8562A has several unobtanium parts.

 

So still a work in progress.

 

Regards

 

Conrad PA5Y

 

From: UKMicrowaves@groups.io <UKMicrowaves@groups.io> On Behalf Of G4SDG via Groups.Io
Sent: 24 January 2020 18:35
To: UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] WTB: HP 5086-7781 YIG module

 

Hello Conrad,

I’m afraid I can’t help you with a YIG module but I wondered what the symptoms with your analyser are. My 8562A is alright when it’s cold but after warm-up I get error messages 317 “Freq Acc” and 307 “YTO Unlock” and sometimes 334 “LO Amp”. They seem to be frequency dependent as well as temperature related. As long as the shack’s cool and my use is short-term I can still use the analyser before the errors appear so I haven’t got around to investigating other than looking through the service manual and checking the 300MHz monitor which appears to be in spec. I wondered if you have any hints?

 

73 Chris G4SDG  


Re: Horn antenna for EME

KENT BRITAIN
 

Very difficult to feed a horn with a patch.  Typically the dimensions of the
patch are far larger than the dimensions of the waveguide.


Yes, you can do optional polarization and even optional feed impedance.

Here is one for 2.4 GHz that is a popular Q-100 dish feed.
Originally designed for commercial drone video feeds, when placed in a
radome the impedance of the antenna changed.  So the 'HI' impedance
attach points allow for the effects of the radome.

Nice big ground plane to attach the shield of the coax too, that decouples
the feed line nicely.    Kent WA5VJB/G8EMY








On Sunday, January 26, 2020, 4:56:34 AM CST, Alan Beard <beardal@...> wrote:


Perhaps you've seen:

To reduce the horn length, can we cut it in half and feed it with
say four patch antennae?
Or four crossed dipoles fed in phase?

Yes more complex to build but the 2.5m length is a problem.

On the subject of patch antenna:

Can we feed it at two places, a chamfered corner patch, to get
right and left circular polarisation?

How does one do a balanced feed to a patch?

---------------------------------------------------
Alan VK2ZIW

OpenWebMail 2.53





Horn antenna for EME

Alan Beard
 

Perhaps you've seen:
http://ok2kkw.com/next/horn_23cm.pdf

To reduce the horn length, can we cut it in half and feed it with
say four patch antennae?
Or four crossed dipoles fed in phase?

Yes more complex to build but the 2.5m length is a problem.

On the subject of patch antenna:

Can we feed it at two places, a chamfered corner patch, to get
right and left circular polarisation?

How does one do a balanced feed to a patch?

---------------------------------------------------
Alan VK2ZIW

OpenWebMail 2.53


Re: 3.4GHz transverter??

Tim, VK2XAX
 

Hi all,

I've just uploaded a video on how to program the SGlabs transverter to a different IF.

https://youtu.be/onsv-g3drx8

cheers

Tim

--

VK2XAX : QF56if : ITU59 : CQ30 : BMARC : WIA


dual hole ferrittes

F1CHF
 

I don't remember WHO was looking for this product
may be Andy ...
have a look here
 
francois F1CHF
 
 


Re: WTB: HP 5086-7781 YIG module

G4SDG
 

Hello Conrad,

I’m afraid I can’t help you with a YIG module but I wondered what the symptoms with your analyser are. My 8562A is alright when it’s cold but after warm-up I get error messages 317 “Freq Acc” and 307 “YTO Unlock” and sometimes 334 “LO Amp”. They seem to be frequency dependent as well as temperature related. As long as the shack’s cool and my use is short-term I can still use the analyser before the errors appear so I haven’t got around to investigating other than looking through the service manual and checking the 300MHz monitor which appears to be in spec. I wondered if you have any hints?

 

73 Chris G4SDG  


Re: Midland RT & Heelweg

G8DQX list
 

Or even: editor@...

(there was a spurious space in Roger's email)

Robin, G8DQX

On 24/01/2020 10:34, Roger Ray via Groups.Io wrote:
Please send to editor@ microwavers.org

Thanks Roger


Re: Midland RT & Heelweg

Roger Ray
 

Please send to editor@ microwavers.org

Thanks Roger


On 24 Jan 2020, at 15:01, Frans van Elk via Groups.Io <pe1fot@...> wrote:



Hello Roger, I have pictures for you but the  email address I have from you is bouncing. 
Can you reply to me via pe1fot@... please.

Best regards
Frans
PE1FOT
On Tuesday, January 21, 2020, 05:22:44 PM GMT+1, Roger Ray via Groups.Io <g8cub@...> wrote:


Input for Scatterpoint

Does anyone have a report and or pictures from the Midland Round Table, and Heelweg?

Thanks

Roger


Groups'io Bouncing

Michael Scott
 

Sorry, another OT message!
Every so often, I get a message from Groups.io saying my e-mails are bouncing and I have to log in and click on a line to un-bounce it. Do others have this problem, and what is the cause?
 
Mike, G3LYP.


Re: Midland RT & Heelweg

Frans van Elk
 


Hello Roger, I have pictures for you but the  email address I have from you is bouncing. 
Can you reply to me via pe1fot@... please.

Best regards
Frans
PE1FOT

On Tuesday, January 21, 2020, 05:22:44 PM GMT+1, Roger Ray via Groups.Io <g8cub@...> wrote:


Input for Scatterpoint

Does anyone have a report and or pictures from the Midland Round Table, and Heelweg?

Thanks

Roger


Re: .pdf Problem

Stephen Tompsett
 

The specification of PDF has changed/evolved ever since is was originally developed and released by by Adobe as a propitiatory specification in 1993, it is now an ISO standard (ISO 32000-2:2017 ) - and may be subject to future changes.

Files conforming to old standards should continue to work with later versions of PDF interpreters, no different to most programs and file formats!

Personally on Windows systems I prefer to use the Foxit (free) reader, but I regularly check for updates.

On 23/01/2020 20:31, Alan Beard wrote:
Guys,

The PDF file standard HAS CHANGED!!!!

Perhaps two or three years ago now. In the new format we can have data entered
by the recipient eg. signatures and tick boxes, The document can then be reviewed
and approved by a supervisor (more data added).

PDF is now a MOVING standard.

But the .PDF file extension stays the same.

-- 
Stephen Tompsett (G8LYB)
Tel: 01788 578940
Mob: 07956 855816


Re: .pdf Problem

Alan Beard
 

Guys,

The PDF file standard HAS CHANGED!!!!

Perhaps two or three years ago now. In the new format we can have data entered
by the recipient eg. signatures and tick boxes, The document can then be reviewed
and approved by a supervisor (more data added).

PDF is now a MOVING standard.

But the .PDF file extension stays the same.

Remember Word Perfect, .WP4, .WP5 and .WP6 the extension changes - good idea.

Do you guys not care about STANDARDS?

Alan VK2ZIW 

On Wed, 22 Jan 2020 20:59:32 +0100, Martin Phillips G4CIO wrote
> I've had the same problem sometimes. Download the file and it opens with Adobe reader but it won't via the browser (Firefox).
>
> Martin/
>
> On 22 January 2020 20:19:17 CET, "Michael Scott via Groups.Io" <g3lyp@...> wrote:

>
> Hi All
>  
> Sorry this is a bit off topic, but opening the new Scatterpoint .pdf file reminded me. Quite often when I try to open a pdf file Windows 10 reports a problem and [UTF-8?]doesn’t open the file, and I have to try again and it always works at the second attempt. I had a look on Google but the usual solution suggested was to uninstall Adobe Reader and reload it. This seemed to work for a while, but in a short time the problem reappeared. This seems to be a problem with W10 as I never had it with XP which I used until I got a new computer.
>  
> Any suggestions would be appreciated!
>  
> 73, Mike, G3LYP.

> --
> Sent from my Android device with K-9 Mail. Please excuse my brevity.

---------------------------------------------------
Alan Beard

OpenWebMail 2.53


Re: .pdf Problem

Murray Niman
 


I tend to use Chrome as default

Ditch Edge  - corporately we use IE as default on Win10. I note  Microsoft have thrown in the towel and will use the Chromium base code in future
I find a lot of Liux pdf readers are hopeless
With care - Not much wrong with Adobe either actually... (inc pdf forms)

   73

     Murray


Re: URM 102 Cioaxial Cable

Brian Howie GM4DIJ
 

In message <trinity-9dd3582f-2c5b-464b-bbcb-5276c2c9bb36-1579801382657@3c-app-mailco
m-lxa14>, "ian hope (2E0IJH)" <ian@...> writes

Many thanks,

It looks like about 25dB/100m at 1.2GHz. Roughly the same as URM 67.

Brian GM4DIJ

 
Attached PDF from the old URM guide
 
Ian
2E0IJH
 
Sent: Thursday, January 23, 2020 at 5:21 PM From: "Brian Howie GM4DIJ"
<brian@...> To: UKMicrowaves@groups.io Subject: [UKMicrowaves]
URM 102 Cioaxial Cable
I've got a reel of URM 102 Coaxial cable. I was given it some time ago
and it lay forgotten in the attic. All I can find is :-
http://www.klaceycables.co.uk/default/public/media/filemanager/URM-lf0h.p
df Silver Plated Copper conductor, Silver Plated Copper Wire Braid .PTFE
dielectric and a Woven Glass Fibre Braid sheath, according to the
above. I'm trying to find a frequency spec. Anyone ? I'm interested in
using it as flexible link to the 13cm and 23cm antennas round the top
bearing or a short feeder for /P I could put a couple of plugs on it and
try it if all else fails. 73 Brian GM4DIJ -- Brian Howie  



[ A MIME application / pdf part was included here. ]
--
Brian Howie


Re: URM 102 Cioaxial Cable

ian hope (2E0IJH)
 

 
Attached PDF from the old URM guide
 
Ian
2E0IJH

 
Sent: Thursday, January 23, 2020 at 5:21 PM
From: "Brian Howie GM4DIJ" <brian@...>
To: UKMicrowaves@groups.io
Subject: [UKMicrowaves] URM 102 Cioaxial Cable
I've got a reel of URM 102 Coaxial cable. I was given it some time ago
and it lay forgotten in the attic.

All I can find is :-

http://www.klaceycables.co.uk/default/public/media/filemanager/URM-lf0h.p
df

Silver Plated Copper conductor, Silver Plated Copper Wire Braid .PTFE
dielectric and a Woven Glass Fibre Braid sheath, according to the
above.

I'm trying to find a frequency spec. Anyone ? I'm interested in using
it as flexible link to the 13cm and 23cm antennas round the top bearing
or a short feeder for /P

I could put a couple of plugs on it and try it if all else fails.

73 Brian GM4DIJ
--
Brian Howie


 


URM 102 Cioaxial Cable

Brian Howie GM4DIJ
 

I've got a reel of URM 102 Coaxial cable. I was given it some time ago and it lay forgotten in the attic.

All I can find is :-

http://www.klaceycables.co.uk/default/public/media/filemanager/URM-lf0h.p
df

Silver Plated Copper conductor, Silver Plated Copper Wire Braid .PTFE dielectric and a Woven Glass Fibre Braid sheath, according to the above.

I'm trying to find a frequency spec. Anyone ? I'm interested in using it as flexible link to the 13cm and 23cm antennas round the top bearing or a short feeder for /P

I could put a couple of plugs on it and try it if all else fails.

73 Brian GM4DIJ
--
Brian Howie