Date   

Re: 9cms PA

Mike Willis
 

There were hundreds of 20W 9cms PAs doing the rounds at rallies three or four years ago. They were made by Stealth Microwave and run off 12V and were selling for quite low prices. Dealers couldn't sell them, I think quite a few were bought for their attractive purple heatsinks. They came in  a box with two and a PSU and diplexers that make good filters typically £25 or less. 

It won't help to point out you should have got one while they were cheap but on the plus side, there are probably a lot of them still about.

While you look, there are also 50W models of that PA and some 15W HP amplifiers which were more efficient. The gain is about 50 dB so you will need an attenuator. 

Mike

--
Mike G0MJW


Re: 9cms PA

Ed G3VPF
 

Oops, sorry about the typo, I meant 10dB gain rather than 20dB, that would be excessive for /P use!

Ed G3VPF


From: Edward Harland
Sent: 06 June 2021 16:49
To: UKMicrowaves@groups.io <UKMicrowaves@groups.io>
Subject: 9cms PA
 
I have the SG-Labs transverter for 9cms but would like to add a PA to up the power about 20dB. Searching the internet does not give any sources of a suitable unit. Kuhne appear to have abandoned the band and could find no-one currently offering the Ionica units.

Does anyone have a suggestion for a suitable power amplifier that is readily available and doesn't weigh a ton (I need it for/P work).

Ed G3VPF


Re: 9cms PA

DF6NA Rainer
 

Hi Ed,

I have 2 new Toshiba UM2683A PA's (50W), a Stealth Microwave SM3436-43 (20W) and a DL2AM 130W amp for sale.
The DL2AM amp needs more drive than you have but the others need less than a mW for full output.

If you are interested make an offer !

vy 73, Rainer


Am 06.06.2021 um 18:49 schrieb Ed G3VPF:

I have the SG-Labs transverter for 9cms but would like to add a PA to up the power about 20dB. Searching the internet does not give any sources of a suitable unit. Kuhne appear to have abandoned the band and could find no-one currently offering the Ionica units.

Does anyone have a suggestion for a suitable power amplifier that is readily available and doesn't weigh a ton (I need it for/P work).

Ed G3VPF


Re: 9cms PA

DD1US
 

Hi Ed,

 

I guess this will be difficult to find. To amplify the 3W by 20dB means you are looking for a 300W PA for the 9cm band.

 

Kind regards

 

Matthias

 

www.dd1us.de

 

 

Von: UKMicrowaves@groups.io <UKMicrowaves@groups.io> Im Auftrag von Ed G3VPF
Gesendet: Sonntag, 6. Juni 2021 18:50
An: UKMicrowaves@groups.io
Betreff: [UKMicrowaves] 9cms PA

 

I have the SG-Labs transverter for 9cms but would like to add a PA to up the power about 20dB. Searching the internet does not give any sources of a suitable unit. Kuhne appear to have abandoned the band and could find no-one currently offering the Ionica units.

 

Does anyone have a suggestion for a suitable power amplifier that is readily available and doesn't weigh a ton (I need it for/P work).

 

Ed G3VPF


9cms PA

Ed G3VPF
 

I have the SG-Labs transverter for 9cms but would like to add a PA to up the power about 20dB. Searching the internet does not give any sources of a suitable unit. Kuhne appear to have abandoned the band and could find no-one currently offering the Ionica units.

Does anyone have a suggestion for a suitable power amplifier that is readily available and doesn't weigh a ton (I need it for/P work).

Ed G3VPF


Re: A quick lashup 2.3 to 3.4 GHz horn

KENT BRITAIN
 

Hi Alan

Most of these horns are used on my antenna range and have Network Analyzer S11 and Gain tables laminated on them.   Yes, they work nicely in 50 Ohm systems.

Traditionally on an exponentiation Slot or Vivaldi antenna the feed point was 1/4 wave in front of a short.
Later is was learned that replacing the 1/4 wave slot with a circle greatly broadened the frequency response of the antenna.     As for the ridges themselves.   The size of the opening determines the lowest frequency they will work at. How close you can position the slots determines the highest frequency.   Basically it's the structure behind the feedpoint that is helping to set the impedance.

Kent

PS  I like to think to the Vivaldi antennas as a ridged horn without the horn! hihi

On Sunday, June 6, 2021, 04:32:47 AM CDT, Alan Beard <beardal@...> wrote:


Thanks Kent,

Can you do a Return Loss plot to determine if the feed impedance is 50 ohms?

I can readily get the gap to between 1 to 2 mm witch surely is close enough for the 4GHz 
or so maximum frequency I intend to use with my HackRF One.

It's a practical thing. I can cut with tin-snips a smooth curve. But to fold metal to simulate
a thicker piece, I cannot achieve a curve, only a straight edge as you see in my image
in the previous email.
From:
https://www.slideshare.net/mariasheebap/ridge-guide
 
My thought, using a very thin ridge puts the  a2/a1 down at 0.01 where the graph becomes obscure.
And the impedances get high.

If the ridge were 1/5th the waveguide broadface width and the  gap was 1/20 the waveguide narrowface,
the impedance would be around 50 ohms. (for their 0.7 a/b waveguide)


And, looking at a Return Loss plot of a 1 - 18 GHz, it was not that good, around 10 to 15db.
With those results, I'm putting my horn on my antenna pole and giving it a go.

Alan VK2ZIW
 


On Sat, 5 Jun 2021 23:05:42 +0000 (UTC), KENT BRITAIN wrote
> I have perhaps a dozen Ridged horns of different sub-species.
>
> Most have a ridge several millimeters wide.
>
> But my 1-18 GHz one has the ridge ground to a fine edge along the top.
>
> I think the fine edge helps the upper frequency limit.   How close you can make the 
> gap between the top and bottom ridges has a major effect on the upper frequency limit of the antenna.
> Kent.
>
> On Saturday, June 5, 2021, 05:13:38 PM CDT, Alan Beard <beardal@...> wrote:
>
> Hi all,
>

> Thanks guys for the pictures of commercial wide band horns but...
>

> Can somebody answer the question please?
>

> The ridge thickness, can it be thin, one sheet of sheet metal, say 1mm ?
>

> (Just like the Vivaldi)
>

> Does this affect the feed impedance?
>

> Here is my SAAV2 scan.
>

> Alan VK2ZIW
>

>

> On Sat, 5 Jun 2021 13:31:05 +0100, Andy G4JNT wrote
> Looks a bit like that, but it's smaller
> Mouth dimensions (internal)  104 x 69mm
>
> Andy
> www.g4jnt.com
>
> On Sat, 5 Jun 2021 at 13:16, Tim Hague M0AFJ via groups.io <m0afj=yahoo.co.uk@groups.io> wrote:
>

> Looks like a 1-18GHz horn similar to the ETS Lindgren / Emco 3115.
>
> Best Regards
> Tim Hague
>
>


---------------------------------------------------
Alan VK2ZIW
Before the Big Bang, God, Sela.
OpenWebMail 2.53, nothing in the cloud.


>

---------------------------------------------------
Alan VK2ZIW
Before the Big Bang, God, Sela.
OpenWebMail 2.53, nothing in the cloud.


Re: Wanted: 10GHz SMA Isolators

Adrian G4UVZ
 

Hi Chris ..think that I might be able to salavge something from a White Box tranverter,,,,not SMA terminated but could be dropped straight into circuit?

A


Re: QO-100

Dave G8KHU
 


Re: QO-100

Dave G8KHU
 

When it gets very narrow you get pictures like this - it doesn't say at what frequency other than "microwaves"
https://www.spaceanswers.com/space-exploration/celebrating-15-years-of-the-spitzer-space-telescope/

The site for the observatory is here
http://www.ovsa.njit.edu/index.html

and includes schematics on their hardware here which shows it has the operating range of 1 -18 GHz
http://www.ovsa.njit.edu/wiki/index.php/Hardware_Overview#Frontend_System

Dave


Re: A quick lashup 2.3 to 3.4 GHz horn

Alan Beard
 

Thanks Kent,

Can you do a Return Loss plot to determine if the feed impedance is 50 ohms?

I can readily get the gap to between 1 to 2 mm witch surely is close enough for the 4GHz 
or so maximum frequency I intend to use with my HackRF One.

It's a practical thing. I can cut with tin-snips a smooth curve. But to fold metal to simulate
a thicker piece, I cannot achieve a curve, only a straight edge as you see in my image
in the previous email.
From:
https://www.slideshare.net/mariasheebap/ridge-guide
 
My thought, using a very thin ridge puts the  a2/a1 down at 0.01 where the graph becomes obscure.
And the impedances get high.

If the ridge were 1/5th the waveguide broadface width and the  gap was 1/20 the waveguide narrowface,
the impedance would be around 50 ohms. (for their 0.7 a/b waveguide)


And, looking at a Return Loss plot of a 1 - 18 GHz, it was not that good, around 10 to 15db.
With those results, I'm putting my horn on my antenna pole and giving it a go.

Alan VK2ZIW
 


On Sat, 5 Jun 2021 23:05:42 +0000 (UTC), KENT BRITAIN wrote
> I have perhaps a dozen Ridged horns of different sub-species.
>
> Most have a ridge several millimeters wide.
>
> But my 1-18 GHz one has the ridge ground to a fine edge along the top.
>
> I think the fine edge helps the upper frequency limit.   How close you can make the 
> gap between the top and bottom ridges has a major effect on the upper frequency limit of the antenna.
> Kent.
>
> On Saturday, June 5, 2021, 05:13:38 PM CDT, Alan Beard <beardal@...> wrote:
>
> Hi all,
>

> Thanks guys for the pictures of commercial wide band horns but...
>

> Can somebody answer the question please?
>

> The ridge thickness, can it be thin, one sheet of sheet metal, say 1mm ?
>

> (Just like the Vivaldi)
>

> Does this affect the feed impedance?
>

> Here is my SAAV2 scan.
>

> Alan VK2ZIW
>

>

> On Sat, 5 Jun 2021 13:31:05 +0100, Andy G4JNT wrote
> Looks a bit like that, but it's smaller
> Mouth dimensions (internal)  104 x 69mm
>
> Andy
> www.g4jnt.com
>
> On Sat, 5 Jun 2021 at 13:16, Tim Hague M0AFJ via groups.io <m0afj=yahoo.co.uk@groups.io> wrote:
>

> Looks like a 1-18GHz horn similar to the ETS Lindgren / Emco 3115.
>
> Best Regards
> Tim Hague
>
>


---------------------------------------------------
Alan VK2ZIW
Before the Big Bang, God, Sela.
OpenWebMail 2.53, nothing in the cloud.


>

---------------------------------------------------
Alan VK2ZIW
Before the Big Bang, God, Sela.
OpenWebMail 2.53, nothing in the cloud.


Wanted: 10GHz SMA Isolators

Chris Bartram G4DGU
 

Hello All,

I'm looking for a couple of small 10GHz ferrite isolators for a new WG input LNA I'm working-on to replace my 2011 design. Does anyone have any they'd be prepared to sell me at a sensible price?

Chris

G4DGU


Re: A quick lashup 2.3 to 3.4 GHz horn

KENT BRITAIN
 

I have perhaps a dozen Ridged horns of different sub-species.

Most have a ridge several millimeters wide.

But my 1-18 GHz one has the ridge ground to a fine edge along the top.

I think the fine edge helps the upper frequency limit.   How close you can make the 
gap between the top and bottom ridges has a major effect on the upper frequency limit of the antenna.
Kent.

On Saturday, June 5, 2021, 05:13:38 PM CDT, Alan Beard <beardal@...> wrote:


Hi all,

Thanks guys for the pictures of commercial wide band horns but...

Can somebody answer the question please?

The ridge thickness, can it be thin, one sheet of sheet metal, say 1mm ?

(Just like the Vivaldi)

Does this affect the feed impedance?

Here is my SAAV2 scan.

Alan VK2ZIW


On Sat, 5 Jun 2021 13:31:05 +0100, Andy G4JNT wrote
> Looks a bit like that, but it's smaller
> Mouth dimensions (internal)  104 x 69mm
>
> Andy
> www.g4jnt.com
>
> On Sat, 5 Jun 2021 at 13:16, Tim Hague M0AFJ via groups.io <m0afj=yahoo.co.uk@groups.io> wrote:
>

> Looks like a 1-18GHz horn similar to the ETS Lindgren / Emco 3115.
>
> Best Regards
> Tim Hague
>
>


---------------------------------------------------
Alan VK2ZIW
Before the Big Bang, God, Sela.
OpenWebMail 2.53, nothing in the cloud.


Re: A quick lashup 2.3 to 3.4 GHz horn

Alan Beard
 

Hi all,

Thanks guys for the pictures of commercial wide band horns but...

Can somebody answer the question please?

The ridge thickness, can it be thin, one sheet of sheet metal, say 1mm ?

(Just like the Vivaldi)

Does this affect the feed impedance?

Here is my SAAV2 scan.

Alan VK2ZIW


On Sat, 5 Jun 2021 13:31:05 +0100, Andy G4JNT wrote
> Looks a bit like that, but it's smaller
> Mouth dimensions (internal)  104 x 69mm
>
> Andy
> www.g4jnt.com
>
> On Sat, 5 Jun 2021 at 13:16, Tim Hague M0AFJ via groups.io <m0afj=yahoo.co.uk@groups.io> wrote:
>

> Looks like a 1-18GHz horn similar to the ETS Lindgren / Emco 3115.
>
> Best Regards
> Tim Hague
>
>


---------------------------------------------------
Alan VK2ZIW
Before the Big Bang, God, Sela.
OpenWebMail 2.53, nothing in the cloud.


Re: QO-100

Andy G4JNT
 

Not sure I do either - in the traditional    2.D²/λ   sense
But when the transmitter is not a point source (not diffraction limited, I think, in optical terms)  there must be some name for it.
The sun is 0.6° wide, so any antenna beamwidth narrower than that gets 'interesting'

 


On Sat, 5 Jun 2021 at 20:17, Dave G8KHU <david@...> wrote:
<< ...in the sun's near field. >>

Not sure I completely agree with that Andy.

If the sun is a single source driving a sun diameter antenna, then yes indeed.

If you consider the sun to be an enormous array of coherent radiaters, then again yes.

However if the sun is considered as an enourmous array of non-coherent, independant small radiators then wouldn't the effective near/Fresnel/far field boundaries would be determined by the geometery of the individual radiator rather than the array geometry?

Dasve G8KHU


Re: dish positioning?

steve G1PPA
 

Hi Ben
That's what I use with simple switch to reverse polarity 12vdc set your the centre to 0deg then
You have equal throw either side , it was suggested to me by G8DMU and it works very well 
Cheers steve
G1PPA 


On Sat, 5 Jun 2021 at 20:47, militaryoperator via groups.io
<Military1944@...> wrote:
Thinking on what someone said I was trying to figure out how to nod the dish up and down to get the best signal. In my case it needs to be very light as its manually raised. I was trying to think about a spring-loaded arrangement and to simply have a cord over a pully coming down the mast which I simply pull on the nod dish dow, releasing it will nod dish back up due to spring. 

or.... ebay 124219350197

The smallest one has 2inch movement which would be more than enough but can't see it it can be nudged in and out or its either fully in or fully out. 

What do others use for nudging their dishes?

Ben
--------

ps:   This one, 124267700578 has a 1inch stoke which should be adequate? I'm assuming its a dc motor, reverse the polarity on leads to get in and out?


Re: dish positioning?

militaryoperator
 

Thinking on what someone said I was trying to figure out how to nod the dish up and down to get the best signal. In my case it needs to be very light as its manually raised. I was trying to think about a spring-loaded arrangement and to simply have a cord over a pully coming down the mast which I simply pull on the nod dish dow, releasing it will nod dish back up due to spring. 

or.... ebay 124219350197

The smallest one has 2inch movement which would be more than enough but can't see it it can be nudged in and out or its either fully in or fully out. 

What do others use for nudging their dishes?

Ben
--------

ps:   This one, 124267700578 has a 1inch stoke which should be adequate? I'm assuming its a dc motor, reverse the polarity on leads to get in and out?


dish positioning?

militaryoperator
 

Thinking on what someone said I was trying to figure out how to nod the dish up and down to get the best signal. In my case it needs to be very light as its manually raised. I was trying to think about a spring-loaded arrangement and to simply have a cord over a pully coming down the mast which I simply pull on the nod dish dow, releasing it will nod dish back up due to spring. 

or.... ebay 124219350197

The smallest one has 2inch movement which would be more than enough but can't see it it can be nudged in and out or its either fully in or fully out. 

What do others use for nudging their dishes?

Ben


Re: QO-100

Dave G8KHU
 

<< ...in the sun's near field. >>

Not sure I completely agree with that Andy.

If the sun is a single source driving a sun diameter antenna, then yes indeed.

If you consider the sun to be an enormous array of coherent radiaters, then again yes.

However if the sun is considered as an enourmous array of non-coherent, independant small radiators then wouldn't the effective near/Fresnel/far field boundaries would be determined by the geometery of the individual radiator rather than the array geometry?

Dasve G8KHU


Re: UK Microwave OPs - Digest #264

Andy G4JNT
 

Yes please, Chris



On Sat, 5 Jun 2021 at 15:31, Chris Bartram G4DGU <chris@...> wrote:




Andy,

If it's the same as the one I have, and it looks suspiciously like it, I
have the manufacturer's data sheet on that horn ...

Let me know if you'd like it.

Chris

G4DGU







Re: UK Microwave OPs - Digest #264

Chris Bartram G4DGU
 

Andy,

If it's the same as the one I have, and it looks suspiciously like it, I have the manufacturer's data sheet on that horn ...

Let me know if you'd like it.

Chris

G4DGU

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