Date   

Re: 3.4G feed horn dimensions ?

Nick Gregory G0HIK
 

Nice Ben,

What is the diameter of your horn? And what function does the flare serve.

If I get this working, I'll be asking you for a sked soon :)

Nick G0HIK


Re: Mere 23cm beacon?

Robin Szemeti - G1YFG
 

Noted.   I may include a "beacons" layer in the mapping on my KST variant.   It would be nice if either of those sites provided beacon data in JSON format,  would save scraping it.

On Sun, 6 Dec 2020 at 15:50, Murray Niman <g6jyb@...> wrote:
For info the static maps on microwavers.org are what are licensed (though may not be great for operational state) and tie up closely with the official data/coordinates on ETCC ukrepeaters.net 

Whereas beaconspot very usefully filters current spot reports (but may not have precise source/keeper data; and can inadvertently omit/include a few extra systems)

Most UK beacons completed their 3yr NoV renewals earlier this year (or were removed if expired), so the RSGB-ETCC licensing info is in a pretty good state. Covid has been hampering site access for some though, so bear that in mind 

73

   Murray G6JYB


--
Robin Szemeti - G1YFG


Re: Mere 23cm beacon?

Murray Niman
 

For info the static maps on microwavers.org are what are licensed (though may not be great for operational state) and tie up closely with the official data/coordinates on ETCC ukrepeaters.net 

Whereas beaconspot very usefully filters current spot reports (but may not have precise source/keeper data; and can inadvertently omit/include a few extra systems)

Most UK beacons completed their 3yr NoV renewals earlier this year (or were removed if expired), so the RSGB-ETCC licensing info is in a pretty good state. Covid has been hampering site access for some though, so bear that in mind 

73

   Murray G6JYB


Re: 3.4G feed horn dimensions ?

Neil Smith G4DBN
 

A simple round horn has a wide pattern and large side/back lobes, so it doesn't illuminate a shallow dish very effectively. That means the horn is probably seeing hot ground, as well as lowering the efficiency of the dish/feed system.

Fitting a choke ring or rings suppresses the sidelobes and helps narrow the pattern somewhat. 

The section of guide ahead of the probe helps to ensure that higher modes are suppressed and that the wavefronts coming out of the tube are pretty much planar so you will get an in-phase reflection across the whole of the dish. Rule of thumb is at least half a waveguide wavelength between the probe and the open end, but you can model it in OpenEMS or something to be sure.

The VE4MA style chokes are much simpler to make (and smaller) than a Chaparral, and you can adjust the width, depth and offset from the open end of the tube to fine-tune the pattern and sidelobe suppression.  W1GHZ's site has a lot of analysis of how to match the choke topology to your dish f/d. On a prime-focus dish, you have to take into account the extra blockage caused by the choke. http://www.w1ghz.org/antbook/chap6-3.pdf and there are good articles in DUBUS.

Without a choke ring, if your dish has an f/d of less than 0.4, you won't lose much on transmit, but you might have a little extra noise on receive. If you are using an offset with f/.d 0.6-0.8 then it is probably worth fitting a choke. It won't make any noticeable difference to the match.

A VE4MA choke ring looks like this, although I usually TIG-weld the rings to the horn - this one needed to be removable for fitting:

Fitting a scalar choke like this one (similar to the Chaparral in concept, providing a high-impedance surface of 1/4-wave (ish) slots) does clean up the pattern very well, but the blockage is too high for a small PF dish under 1.5 m or a 1.2 m offset

Neil G4DBN

On 06/12/2020 14:34, Nick Gregory G0HIK via groups.io wrote:
The 9cm's SG-Labs arrived yesterday and I'm cant wait to get going.

I've found on the G3PHO site a "Soup Tin" feed horn.

I've copied it and the SWR is in the green straight away :)

But what length should I make the waveguide section, it is not mentioned in the article ?

And what does a Chaparral horn actually do ?

Nick G0HIK
 






-- 
Neil
http://g4dbn.uk


Re: 3.4G feed horn dimensions ?

militaryoperator
 


Mine Nick. 


Ben G4BXD.




Subject: [UKMicrowaves] 3.4G feed horn dimensions ?
The 9cm's SG-Labs arrived yesterday and I'm cant wait to get going.
I've found on the G3PHO site a "Soup Tin" feed horn.
I've copied it and the SWR is in the green straight away :)
But what length should I make the waveguide section, it is not mentioned in the article ?
And what does a Chaparral horn actually do ?
Nick G0HIK


 





Re: 3.4G feed horn dimensions ?

Nick Gregory G0HIK
 

Thanks John,

That is just the simple to understand information I needed.

I'll try it with just the open ended can first then.

Nick G0HIK


Re: 3.4G feed horn dimensions ?

John Fell
 

Nick,
The standard tin length is good enough - the probe point to the end short of the waveguide ( Tin can) is more important .
No doubt Peter's data will be fine .
The Chaparral flange addition is to enforce a better distribution  illumination of the dish surface for higher F/d ratio .

The open ended can without any flange addition will work fine with a near prime (0.25 F/d ratio ) reflector , which requires near to 90 degree feed angle .

An alternative , easier to make , flange is a Super VE4MA .This works well with dishes in  the 0.55 to 0.8F/d range , such as the majority of domestic  Sat dishes .It is also possible to adjust the flange position although the data given on the W1GHZ website is close enough to fix the position .

73/Seasons Greetings 

John
G0API

On Sun, 6 Dec 2020 at 14:34, Nick Gregory G0HIK via groups.io <nickg0hik=googlemail.com@groups.io> wrote:
The 9cm's SG-Labs arrived yesterday and I'm cant wait to get going.

I've found on the G3PHO site a "Soup Tin" feed horn.

I've copied it and the SWR is in the green straight away :)

But what length should I make the waveguide section, it is not mentioned in the article ?

And what does a Chaparral horn actually do ?

Nick G0HIK
 







3.4G feed horn dimensions ?

Nick Gregory G0HIK
 

The 9cm's SG-Labs arrived yesterday and I'm cant wait to get going.

I've found on the G3PHO site a "Soup Tin" feed horn.

I've copied it and the SWR is in the green straight away :)

But what length should I make the waveguide section, it is not mentioned in the article ?

And what does a Chaparral horn actually do ?

Nick G0HIK
 







Re: 3.4G

DF6NA Rainer
 

Hi,

just look for these ANAREN 1H0566-3. They are good for 100W from 2-4GHz.

73, Rainer



Am 06.12.2020 um 11:09 schrieb Colin Ranson:

Stuart, Hi,

 

I have a few of these for 2.3-2.7GHz,  same manufacturer, but I did not think they would handle high power......   up to 70W as the ones you list.

 

Thanks for the attention

 

Regards

 

Colin.

 

Sent from Mail for Windows 10

 

From: Stuart G1ZAR
Sent: 06 December 2020 10:00
To: UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] 3.4G

 

Could you use one of the surface mount type couplers such as Anaran XC3500M  or similar higher power unit.
What would be involved in making a suitable PCB? or am I looking at the wrong item entirely?

regards.............Stuart

 



Re: Mere 23cm beacon?

Robin Szemeti - G1YFG
 

Its the only 23cm beacon I can hear normally!   Considering I am off the back of the dish ...

On Sun, 6 Dec 2020 at 10:05, Graham G3TCT <g3tct@...> wrote:
GB3USK is indeed off at the moment, don't panic!  It is solar powered. 
The combination of short days, 8/8 cloud and reduced battery capacity at
low temperatures means the months of December and January are
difficult.  It will re-appear from time to time during this period, but
rather unreliable.

Good to know it's useful when it's on though!  It was a good signal on
the Gerbrandy websdr last Sunday.

73
Graham






--
Robin Szemeti - G1YFG


Re: 3.4G

Colin Ranson
 

Stuart, Hi,

 

I have a few of these for 2.3-2.7GHz,  same manufacturer, but I did not think they would handle high power......   up to 70W as the ones you list.

 

Thanks for the attention

 

Regards

 

Colin.

 

Sent from Mail for Windows 10

 

From: Stuart G1ZAR
Sent: 06 December 2020 10:00
To: UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] 3.4G

 

Could you use one of the surface mount type couplers such as Anaran XC3500M  or similar higher power unit.
What would be involved in making a suitable PCB? or am I looking at the wrong item entirely?

regards.............Stuart

 


Re: Mere 23cm beacon?

Graham G3TCT
 

GB3USK is indeed off at the moment, don't panic! It is solar powered. The combination of short days, 8/8 cloud and reduced battery capacity at low temperatures means the months of December and January are difficult. It will re-appear from time to time during this period, but rather unreliable.

Good to know it's useful when it's on though! It was a good signal on the Gerbrandy websdr last Sunday.

73
Graham


Re: 3.4G

Stuart G1ZAR
 

Could you use one of the surface mount type couplers such as Anaran XC3500M  or similar higher power unit.
What would be involved in making a suitable PCB? or am I looking at the wrong item entirely?

regards.............Stuart


Re: 3.4G

g4bao
 

Indeed, you only have to look at any Ham design combining multiple PA modules to see that! Why reinvent the wheel? 

For mine, I calculated the line dimensions and modelled it with QUCS (free software), then I EM Modelled it in the box with Sonnet lite (free software)
Drew the final PCB dimensions from Sonnet in to Eagle 5 (free software)
Laser printed two of them on Press N peel on a free sample of Rogers board from the Rodgers website
Both worked first time!

Charlie G3WDG did a design for a 6cm hybrid as well but clearly tolerances get tighter the higher you go. Doing that so easily at 10GHz might be a bigger challenge but there are plenty of designs around for that band and even some for for 24GHz using microstrip hybrids!

Finally If anyone comes across an Ionica output combiner (look on my website under projects)
http://www.g4bao.com/page4.htm
I show how you can easily hack the 3.5GHz hybrid down on to 3.4GHz with some Kapton tape.

73
John
 


Re: 3.4G

g4bao
 

Neil I think you are a little cautious about proper SMA connectors at the 100W level. I and quite a few others use ILAM amps for 13cm EME that run close to 250W through one, and the output microstrip hybrid for my 2x40W PA at 9cm uses them.
No issues with them failing yet.

See https://www.electronics-notes.com/articles/electronic_components/rf-connectors/sma-connector.php

Unlike my cheap Chinese directional coupler with N connectors on it that burned out at 300W on 23cm!

73
John

     


Re: 23cm interference

Dave - G4RQI
 

No but I will once the 70cm yagi goes up ready for Tuesday night... ta

David


From: UKMicrowaves@groups.io <UKMicrowaves@groups.io> on behalf of g4bao <john@...>
Sent: Saturday, December 5, 2020 12:52:08 PM
To: UKMicrowaves@groups.io <UKMicrowaves@groups.io>
Subject: Re: [UKMicrowaves] 23cm interference
 
Have you looked for it on 432.58?

I have something similar here.
3rd harmonic of some sort of crappy licence free thingy.

73
John


Re: Mere 23cm beacon?

Robin Szemeti - G1YFG
 

Hi John,

I shall register ... I always assumed it was the same info as https://www.microwavers.org/maps/23cms.htm  as they looked similar.


On Sat, 5 Dec 2020 at 21:32, John Lemay <john@...> wrote:

Robin

 

You can take a look at beaconspot.uk. Plenty of info on all the beacons everywhere. If a beacon has an outage, there is a facility for the beacon-keeper to insert relevant details. It’s also really useful for those beacons that are not frequency locked because you can see the official frequency plus where they have wandered to at the most recent spot.

 

John G4ZTR

 

From: UKMicrowaves@groups.io [mailto:UKMicrowaves@groups.io] On Behalf Of Robin Szemeti - G1YFG
Sent: 05 December 2020 18:22
To: UKMicrowaves@groups.io
Subject: [UKMicrowaves] Mere 23cm beacon?

 

USK ... I can't seem to hear it ... is it off?


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Best regards,

Robin Szemeti

Redpoint Consulting Limited

E: robin@...
T: +44 (0) 1299 405028
M: +44 (0) 7971 883371

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Re: Mere 23cm beacon?

John Lemay
 

Robin

 

You can take a look at beaconspot.uk. Plenty of info on all the beacons everywhere. If a beacon has an outage, there is a facility for the beacon-keeper to insert relevant details. It’s also really useful for those beacons that are not frequency locked because you can see the official frequency plus where they have wandered to at the most recent spot.

 

John G4ZTR

 

From: UKMicrowaves@groups.io [mailto:UKMicrowaves@groups.io] On Behalf Of Robin Szemeti - G1YFG
Sent: 05 December 2020 18:22
To: UKMicrowaves@groups.io
Subject: [UKMicrowaves] Mere 23cm beacon?

 

USK ... I can't seem to hear it ... is it off?


--

Best regards,

Robin Szemeti

Redpoint Consulting Limited

E: robin@...
T: +44 (0) 1299 405028
M: +44 (0) 7971 883371

CONFIDENTIALITY NOTICE
The information contained in this e-mail is intended only for the
confidential use of the above named recipient. If you are not the
intended recipient or person responsible for delivering it to the
intended recipient, you have received this communication in error
and must not distribute or copy it.
Please accept the sender's apologies, notify the sender immediately
by return e-mail and delete this communication.

Thank you.


--
Robin Szemeti - G1YFG


Virus-free. www.avg.com


Re: Mere 23cm beacon?

Robin Szemeti - G1YFG
 

Ta, noted.  I'm going to assume it was just off then and I don't have to panic about my receiver.

On Sat, 5 Dec 2020 at 20:56, Andy G4JNT <andy.g4jnt@...> wrote:

On Sat, 5 Dec 2020 at 20:41, Robin Szemeti - G1YFG <robin@...> wrote:
I couldn't hear it at 2pm either ... is it solar powered?  Maybe today was just too dull?

On Sat, 5 Dec 2020 at 20:02, Martin Phillips G4CIO <martin@...> wrote:
It only works in daylight hours.

On 5/12/20 6:21 PM, Robin Szemeti - G1YFG wrote:
USK ... I can't seem to hear it ... is it off?

--
Best regards,

Robin Szemeti

Redpoint Consulting Limited 

E: robin@... 
T: +44 (0) 1299 405028 
M: +44 (0) 7971 883371 

CONFIDENTIALITY NOTICE 
The information contained in this e-mail is intended only for the
confidential use of the above named recipient. If you are not the
intended recipient or person responsible for delivering it to the
intended recipient, you have received this communication in error 
and must not distribute or copy it. 
Please accept the sender's apologies, notify the sender immediately 
by return e-mail and delete this communication. 

Thank you. 

--
Robin Szemeti - G1YFG



--
Robin Szemeti - G1YFG


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Robin Szemeti - G1YFG


Re: Mere 23cm beacon?

Andy G4JNT
 


On Sat, 5 Dec 2020 at 20:41, Robin Szemeti - G1YFG <robin@...> wrote:
I couldn't hear it at 2pm either ... is it solar powered?  Maybe today was just too dull?

On Sat, 5 Dec 2020 at 20:02, Martin Phillips G4CIO <martin@...> wrote:
It only works in daylight hours.

On 5/12/20 6:21 PM, Robin Szemeti - G1YFG wrote:
USK ... I can't seem to hear it ... is it off?

--
Best regards,

Robin Szemeti

Redpoint Consulting Limited 

E: robin@... 
T: +44 (0) 1299 405028 
M: +44 (0) 7971 883371 

CONFIDENTIALITY NOTICE 
The information contained in this e-mail is intended only for the
confidential use of the above named recipient. If you are not the
intended recipient or person responsible for delivering it to the
intended recipient, you have received this communication in error 
and must not distribute or copy it. 
Please accept the sender's apologies, notify the sender immediately 
by return e-mail and delete this communication. 

Thank you. 

--
Robin Szemeti - G1YFG



--
Robin Szemeti - G1YFG

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