New world record on 30THz


Barry Chambers
 
Edited

Today, Barry G8AGN/P and Bob G4APV/P set a new world record of 65m  on the 30THz band. Reports both ways were 599 and the equipment used was the same as for previous shorter contacts.

The contact took place in the grounds of the Finningley Amateur Radio Society (FARS) and special thanks are due to Kevin G3AAF who acted as our host, kept us supplied with coffee and acted as the contact adjudicator. Several other club members were also present during parts of the 6 hour long operating session which included time involved in measuring out the path length and waiting for the rain to stop!

The weather was mixed, mainly overcast with variable light wind and the occasional light rain shower (typical for a late May Bank Holiday weekend!). Propagation conditions were very variable with periods of no wind and 100% copy; at other times,  light winds seemed to churn up the atmosphere and increase path attenuation and/or induce deep signal fades/scintillation?

A photo is attached. Some video was also taken but has not been viewed/edited yet,

--
73
Barry, G8AGN


Roger Ray
 

Brilliant well done Barry. Propagation on 30THz is pretty unknown.

Roger
G8CUB

On 22 May 2021, at 19:46, Barry Chambers <b.chambers@sheffield.ac.uk> wrote:

Today, Barry G8AGN/P and Bob G4APV/P set a new world record of 65m on the 30THz band. Reports both ways were 599 and the equipment used was the same as for previous shorter contacts.

The contact took place in the grounds of the Finningley Amateur Radio Society (FARS) and special thanks are due to Kevin G3AAF who acted as our host, kept us supplied with coffee and acted as the contact adjudicator. Several other club members were also present during parts of the 6 hour long operating session which included time involved in measuring out the path length and waiting for the rain to stop!

The weather was mixed, mainly overcast with variable light wind and the occasional light rain shower (typical for a late May Bank Holiday weekend!). Propagation conditions were very variable with periods of no wind and 100% copy; at other times, light winds seemed to churn up the atmosphere and increase path attenuation and/or induce deep signal fades/scintillation?

A photo is attached. Some video was also taken but has not been viewed/edited yet,

--
73
Barry, G8AGN






<IMG_3721.JPG>


Raymond Brooks
 

Brilliant well done to all.

On 22 May 2021 20:30, "Roger Ray via groups.io" <g8cub@...> wrote:

Brilliant well done Barry. Propagation on 30THz is pretty unknown.

Roger
G8CUB
> On 22 May 2021, at 19:46, Barry Chambers <b.chambers@...> wrote:
>
> Today, Barry G8AGN/P and Bob G4APV/P set a new world record of 65m  on the 30THz band. Reports both ways were 599 and the equipment used was the same as for previous shorter contacts.
>
> The contact took place in the grounds of the Finningley Amateur Radio Society (FARS) and special thanks are due to Kevin G3AAF who acted as our host, kept us supplied with coffee and acted as the contact adjudicator. Several other club members were also present during parts of the 6 hour long operating session which included time involved in measuring out the path length and waiting for the rain to stop!
>
> The weather was mixed, mainly overcast with variable light wind and the occasional light rain shower (typical for a late May Bank Holiday weekend!). Propagation conditions were very variable with periods of no wind and 100% copy; at other times,  light winds seemed to churn up the atmosphere and increase path attenuation and/or induce deep signal fades/scintillation?
>
> A photo is attached. Some video was also taken but has not been viewed/edited yet,
>
> --
> 73
> Barry, G8AGN
>
>
>
>
>
>
> <IMG_3721.JPG>








--
Raymond G8KPS


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


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 


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


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


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


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


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