Date   

Re: Activity List for the UK Microwave Group 5.7GHz and 10GHz Contests - Sunday 30th May

militaryoperator
 

Callsign: G4BXD
Locator:  IO82UJ
Bands:    5.7GHz not finished it yet!!
               10GHz 5W 46cm dish
Talkback: ON4KST and Zello
Times: Various throughout



Re: LED Lighting noise

Alan Melia
 

Rich please offer them to David Lauder emc.radcom@rsgb.org.uk. David writes the EMC column in Radcom and is keen to collect units like yours for analysis. Most dont meet the required specs because the do not have the filter components installed !! If we get enough sample it is easier to bang a few heads !!

Alan
G3NYK

----- Original Message -----
From: "G8ZHA via groups.io" <g8zha-1=blueyonder.co.uk@groups.io>
To: <UKMicrowaves@groups.io>
Sent: Monday, May 24, 2021 10:20 PM
Subject: [UKMicrowaves] LED Lighting noise


For info, I have solved my noise issue from my HiSpec LED lights. I have
replaced the drivers with a Meanwell APC-12-350, at a cost of £13 each.
Equal to the cost of the Hispec light and driver, so you get what you pay
for.

If anyone wants a crap noisy smps to experiment with let me know, before I
chuck them in the scrap bin!

Rich G8ZHA


Small order quantity ASF250 MMIC

Conrad, PA5Y
 

Does anyone know where I can buy a few ASF-250s from?

 

Regards

 

Conrad PA5Y


LED Lighting noise

G8ZHA
 

For info, I have solved my noise issue from my HiSpec LED lights. I have replaced the drivers with a Meanwell APC-12-350, at a cost of £13 each. Equal to the cost of the Hispec light and driver, so you get what you pay for.

If anyone wants a crap noisy smps to experiment with let me know, before I chuck them in the scrap bin!

Rich G8ZHA


Activity List for the UK Microwave Group 5.7GHz and 10GHz Contests - Sunday 30th May

John Quarmby
 

The first of the summer series of UKuG 5.7GHz and 10GHz contests takes place this Sunday, 30th May.

Stations can enter for a maximum operating period of 8 hours between 0600z and 1800z (0700 - 1900BST).

Full rules are here: https://www.microwavers.org/files/2021-mwrules.pdf

The signs are that the weather might be better by then so I hope more can get out portable.

As usual I will compile an activity list and circulate it on Saturday 29th May, please post your plans in the usual format by 28th May:

Callsign: G3XDY
Locator: JO02OB
Bands: 5.7GHz 15W 60cm dish
             10GHz 10W 60cm dish
Talkback: ON4KST and Zello
Times: Various throughout

73

John G3XDY
UKuG Contest Manager


--
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus


Re: uwb antenna question

KENT BRITAIN
 

I agree and have been selling Planar Disk UWB antennas for 10 years.

Something to 'watermark' the design and looks cool.    Kent

On Monday, May 24, 2021, 02:53:57 PM CDT, Ken G3YKI <kenneth@...> wrote:


I suggest that the loops are mainly for decoration rather than function. A solid disc would work as a wideband antenna.


Re: New world record on 30THz

Barry Chambers
 

Hi Murray

I will take a look.

Barry

On 24/05/2021 17:42, Murray Niman wrote:
Hi Barry

am sure they are quite pricey to start with, but its amazing what you can find with a search on 'LWIR' on eBay or Alibaba

cheers

 Murray
-- 
73
Barry, G8AGN


Re: uwb antenna question

 

I suggest that the loops are mainly for decoration rather than function. A solid disc would work as a wideband antenna.


uwb antenna question

Rien Eradus PA0JME
 

A belgian radiofriend of mine just sent me this link and asked if this is a usefull antenna?
https://nl.grandado.com/products/2-4-10-5g-uwb-ultra-wideband-antenne-module-uwb-uwb-antenne-puls-antenne-2?utm_source=criteo&utm_medium=display&utm_campaign=lower_funnel&variant=UHJvZHVjdFZhcmlhbnQ6NDQ4ODkwMzI
I am a bit puzzled how the feedline is configured,
Possibly the loops are resonant on frequencis ranging from 2.4 to 10.x GHz, but feeding those is to my mind a bit weird.
Any suggestions are welcome.


Re: New world record on 30THz

Brian Howie GM4DIJ
 

On 24/05/2021 17:17, Barry Chambers wrote:
Hi Murray
thanks for your comments. I would guess that the sensors we are using are much cheaper/less sophisticated than the military/security ones?
73 Barry G8AGN
The ones I used were Mercury Cadmium Telluride cooled to 77K. Single element for laser range finding and arrays for thermal imagers. The arrays cost a fortune.

I've played with cheap uncooled pyro-electrics too. They're broad band. I think I might have some.

You might want to try the 3-5um band (60THz). I've used uncooled Lead Selenide there. A soldering iron makes a good source !.

Brian GM4DIJ

--
Brian


Re: New world record on 30THz

Murray Niman
 

Hi Barry

am sure they are quite pricey to start with, but its amazing what you can find with a search on 'LWIR' on eBay or Alibaba

cheers

 Murray


Re: How does this POTY antenna work??

Chris Wilson
 

Hello John,

Wednesday, May 19, 2021

Thank you John, Colin and Paul for the explanations of this set up, much appreciated, I now see how it works and understand much better. As a bit of technical eye candy it scores highly, too, in my book :)


Best regards,
Chris 2E0ILY mailto:chris@chriswilson.tv


JF> Chris,
JF> The pic shows a circular patch feed for 2.4GHz , similar to the
JF> POTY type .The N elbow feeds 2.4GHz RF to the patch element .
JF> His site says he uses a 20W PA , so depending on the attenuation
JF> along the TX cable , he should put in a reasonable signal .


JF> My system outputs 1.5W via a 5m run of LDF450 Heliax via an 80cm
JF> offset - that puts my signal at -5dB relative to the Beacons on QO100.


JF> The SMA lead will connect a probe inside the round waveguide to
JF> the downconverter behind the assembly. An LNB is a downconverter ,
JF> in this case a block + antenna .The N elbow plug will carry
JF> downconverted RF and DC to the shack end unit that will supply the
JF> required output RF for the radio in use.


JF> What is interesting to see is the conical horn and rear choke
JF> flange (?) . I would be interested to know what interactions
JF> /pattern distortion occur on 2.4GHz .
JF> Certainly the feed will be more efficient than open ended waveguide at 10GHz .


JF> 73
JF> John
JF> G0API
JF> On Wed, 19 May 2021 at 10:32, Chris Wilson <chris@chriswilson.tv> wrote:


JF>
JF> 19/05/2021 10:19
JF>
JF> I am slowly getting into amateur satellite work and runa 1.8
JF> meter prime focus dish with a POTY antenna for 2.4GHz TX and a
JF> coaxial LNB for circa 10.5GHz reception. I know the LNB down
JF> converts to around 940 MHz using an intermediate frequency.
JF>
JF> I heard a very nice signal from a chap who appeared to know a
JF> lot about the hardware used, so looked him up on qrz.com He was
JF> using a POTY antenna the like of which I have not seen before. It
JF> has a feed horn and appears to feed the RX side without an LNB
JF> directly to a Kuhne down converter. How might that work, I thought
JF> down converters expected a lot of gain from the LNB and an already
JF> down converted signal, to some extent, done within the LNB?
JF>
JF>
JF> I placed a photo of this nicely looking engineered device here:
JF>
JF> http://www.chriswilson.tv/DJ8EI.JPG
JF>
JF> It appears there's no LNB but the RX antenna is inside the POTY tube itself.
JF>
JF>
JF> Thanks for any insight to this newbie!
JF>
JF> --
JF> Best Regards,
JF> Chris Wilson.
JF> mailto: chris@chriswilson.tv
JF>
JF>
JF>
JF>
JF>
JF>
JF>
JF>


Re: New world record on 30THz

Barry Chambers
 

Brian

thanks for your comments. I'm aware of the window around 30THz and the xxxTRAN software as I used to get the latest versions from the US as part of my day job. Many years ago I also had some interest in CO2 and HCN lasers but they were only bench/lab models so rather big for /p use! The advantage of heated plates is that you can cook your burgers on them after operating!

73 Barry, G8AGN

On 24/05/2021 13:10, Brian Howie GM4DIJ wrote:
On 22/05/2021 20:30, Roger Ray via groups.io wrote:
Brilliant well done Barry. Propagation on 30THz is pretty unknown.

Roger
G8CUB
It's the 10um Infrared Window.(8-12um)  Propagation of IR in this band (and others) used to be part of my day job. Over 65m there's almost no loss between 25 and 40THz.

Industry standard atmospheric model is Modtran, but it is not cheap.

The older standard Lowtran is available for free.

https://github.com/space-physics/lowtran

These guys need to get a hold of some CO2 lasers ;-)

Pretty good going with just modulated hot-plates.

Brian GM4DIJ

--
73
Barry, G8AGN


Re: New world record on 30THz

Barry Chambers
 

Hi Murray

thanks for your comments. I would guess that the sensors we are using are much cheaper/less sophisticated than the military/security ones?

73 Barry G8AGN


On 24/05/2021 14:30, Murray Niman wrote:
Well done on the latest effort

however as mentioned, 10um is extremely well characterised as LWIR is a key lowish loss window for some IR imagers for kilometres range

The interesting thing in future though is that instead of it being a thermal approach, technology is capable of true rf reception at these small wavelengths as nanoantennas and related developments make progress

73

  Murray G6JYB 
-- 
73
Barry, G8AGN


Re: New world record on 30THz

Murray Niman
 

Well done on the latest effort

however as mentioned, 10um is extremely well characterised as LWIR is a key lowish loss window for some IR imagers for kilometres range

The interesting thing in future though is that instead of it being a thermal approach, technology is capable of true rf reception at these small wavelengths as nanoantennas and related developments make progress

73

  Murray G6JYB 


SHUSH.. Dont tell Greta

militaryoperator
 

we had better hope that old save the planet Greta never learns about ham radio, microwaves and SMD. She would go barmy. 

for these
DSCF3903.JPG

I threw away this

DSCF3904.JPG

Ben


Re: New world record on 30THz

Brian Howie GM4DIJ
 

On 22/05/2021 20:30, Roger Ray via groups.io wrote:
Brilliant well done Barry. Propagation on 30THz is pretty unknown.
Roger
G8CUB
It's the 10um Infrared Window.(8-12um) Propagation of IR in this band (and others) used to be part of my day job. Over 65m there's almost no loss between 25 and 40THz.

Industry standard atmospheric model is Modtran, but it is not cheap.

The older standard Lowtran is available for free.

https://github.com/space-physics/lowtran

These guys need to get a hold of some CO2 lasers ;-)

Pretty good going with just modulated hot-plates.

Brian GM4DIJ


--
Brian


Re: How does this POTY antenna work??

Paul Randall G3NJV
 

Beautifully engineered indeed. However that coaxial link from the waveguide to the Kuhne box will introduce loss and thus degrade the rx noise figure compared to what you might get with the more direct connection found inside a typical LNB.

Perhaps someone has done comparative measurements on these two approaches?



Sent from my Galaxy



-------- Original message --------
From: Colin G4EML <colin@...>
Date: 19/05/2021 10:48 (GMT+00:00)
To: UKMicrowaves@groups.io
Subject: Re: [UKMicrowaves] How does this POTY antenna work??

The Kuhne down converter does exactly the same job as a regular LNB. It just has a coax input instead of having an integral antenna. That arrangement simply connects an external antenna to it.

It is not really correct to call that a POTY antenna. The POTY is the name of a specific design, not a generic term.

Colin G4EML



On 19 May 2021, at 10:32, Chris Wilson <chris@...> wrote:



 19/05/2021 10:19

I am slowly getting into amateur satellite work and runa 1.8 meter prime focus dish with a POTY antenna for 2.4GHz TX and a coaxial LNB for circa 10.5GHz reception. I know the LNB down converts to around 940 MHz using an intermediate frequency.

I heard a very nice signal from a chap who appeared to know a lot about the hardware used, so looked him up on qrz.com  He was using a POTY antenna the like of which I have not seen before. It has a feed horn and appears to feed the RX side without an LNB directly to a Kuhne down converter. How might that work, I thought down converters expected a lot of gain from the LNB and an already down converted signal, to some extent, done within the LNB?


I placed a photo of this nicely looking engineered device here:

http://www.chriswilson.tv/DJ8EI.JPG

It appears there's no LNB but the RX antenna is inside the POTY tube itself.


Thanks for any insight to this newbie!

--
      Best Regards,
                  Chris Wilson.
mailto: chris@...













Re: Building a simple 10 ghz beacon ?

Mihai, YO8RHM
 

I made a beacon in 23cm with the PLL from vhfdesign that has been working very well for 3 years on a 1650m peak (it still works !). It is a solution that fits very well with a beacon. From the PLL I amplify the signal with a PGA103 with which I attack an integrated RA18H1213G and the output power is 5W. Unfortunately, those from vhfdesign have currently stopped production for various reasons generated by the situation from Ukraine. You can contact Pavel from vhfdesign on Skype to request information by searching for his call US4ICI.

Mihai YO8RHM


Re: Building a simple 10 ghz beacon ?

Steve G4HTZ
 

They do speak good English …and good to deal with …I’ve had a few pre amps from them in the past .
ive got one of the devices here and it does what it says as per the video 
regards 
steve 
--
Steve G4HTZ 
JO01JN60
Great Wakering, Essex 
24ghz 1.8w 80cm dish 

also known to be active occasionally on 70cms DATV 

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