10GHz World Record


Christopher Bartram <cbartram@...>
 

I'd like to add my congratulations to VK7MO and VK6DZ to those of Roger. It's interesting that their QSO was made using JT4 ...

It's worth noting that there seems to be an unobstructed oversea great-circle path from Southerness, on the Solway, to the northern end of Tenerife. Several years ago, I was trying to generate interest in EA8 for tests on 10GHz, but at that time, despite some interest, EAs weren't licenced for the band, and, understandably, nobody wanted to try. Now there is both interest and activity on the Canaries, the potential exists for a GM-EA8 world record ...

Vy 73

Chris
GW4DGU
--


John Fell
 

I agree with Chris - it is a very FB effort !

Somewhere near to Port William - IO74RR does indeed just scrape past EI to make the seapath down to the Canaries , so it would be interesting .

If that goes there is a slightly longer sea path that I found between Goular on North Uist , IO67FO to Cabedelo in Paraiba HI23OA08 - that would be a GM/SA first on 10GHz at a mere 7599.6km.
Now, how to erect a pair of EME size stations launching into the super refractive duct , would make for some thought......

HNY/V 73
John
G0API

Well its been a wet old day so making helical antennas for 10GHz and listening to GB3SCX from inside this warm shack.

On 12 January 2015 at 10:09, Christopher Bartram cbartram@... [ukmicrowaves] <ukmicrowaves@...> wrote:
 

I'd like to add my congratulations to VK7MO and VK6DZ to those of Roger.
It's interesting that their QSO was made using JT4 ...

It's worth noting that there seems to be an unobstructed oversea
great-circle path from Southerness, on the Solway, to the northern end
of Tenerife. Several years ago, I was trying to generate interest in EA8
for tests on 10GHz, but at that time, despite some interest, EAs weren't
licenced for the band, and, understandably, nobody wanted to try. Now
there is both interest and activity on the Canaries, the potential
exists for a GM-EA8 world record ...

Vy 73

Chris
GW4DGU
--



Ian White
 

GW4DGU wrote:


It's worth noting that there seems to be an unobstructed oversea
great-circle path from Southerness, on the Solway, to the northern end
of Tenerife. Several years ago, I was trying to generate interest in EA8
for tests on 10GHz, but at that time, despite some interest, EAs weren't
licenced for the band, and, understandably, nobody wanted to try. Now
there is both interest and activity on the Canaries, the potential
exists for a GM-EA8 world record ...
West of Southerness the path becomes blocked by the Isle of Man, but it resumes again on the eastern shore of Luce Bay, close to where the historic 10GHz QSOs were made to St David's Head. This more westerly path to EA8 is actually better than the easterly path because it includes the entire north shore of Tenerife and most of the north shore of Gran Canaria too.

From the home QTH, I have all but the last 5km...


73 from Ian GM3SEK


Roger Ray
 

Having a sea path is one thing, but has there ever been evidence of a duct that far north?  Still I will be in North Gran Canaria later in the year....

Roger
G8CUB


Dave G4RGK .
 

On 12/01/2015 10:09, Christopher Bartram cbartram@... [ukmicrowaves] wrote:
I was trying to generate interest in EA8
for tests on 10GHz, but at that time, despite some interest, EAs weren't
licenced for the band, and, understandably, nobody wanted to try. Now
there is both interest and activity on the Canaries, the potential
exists for a GM-EA8 world record ...
Chris,

The biggest problem is getting a microwave licence down there, I and several other emers have spent years trying to get a licence for years. The current conditions are here:

http://www.ure.es/english/general-information/417-licensing-and-basic-info-for-visitor-hams-.html

73 Dave G4RGK


Christopher Bartram <cbartram@...>
 

Hello Roger

It depends on the evidence you need ... Certainly, surface ducts occur in the Irish Sea - don't forget the 500km WB QSO between GM and Cornwall back in the '70s. Also, much of the original (WW2) European work on microwave propagation over the sea took place in the Irish Sea basin, and that certainly showed the presence of both surface and elevated ducts.

Whether the path to EA8 would be via a surface (maritime evaporation) duct is a moot point. I suspect that an elevated duct would be more likely, and I'd be interested to hear from someone with professional knowledge of the subject. Certainly, EA8 - GM tropo QSOs have been made at VHF.

My experience with the EA8/CT3/CU paths from my old IO71 QTH was that there were quite regular openings covering up to at least 432 (at that time, AFAIK, there was no legal 1.3GHz activity from EA) and that at times signals were very strong indeed - at times probably well below free-space values. I was a few 10s of km inland, and I strongly suspect that on these occasions propagation would have been via an elevated duct. Stations in more coastal locations experienced propagation to the Atlantic Islands more regularly.


Vy 73

Chris
GW4DGU
--
Christopher Bartram MIET
Christopher Bartram RF Design
Llygad yr Haul
Carno
CAERSWS
Powys SY17 5LE

phone: +44 1686 237732
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Ian White
 


Having a sea path is one thing, but has there ever been evidence of a duct
that far north? Still I will be in North Gran Canaria later in the year....

Roger
G8CUB
On 2m, yes, and I believe on 70cm also. Unfortunately those contacts have been displaced from the record tables by more recent longer contacts, so they are in danger of becoming lost.

At higher frequencies, I've had the phone go off in my pocket with a "Welcome" text from Jersey. That is not a sea path to SW Scotland so aircraft scatter might also have been involved; but that is another valid possibility to extend a long tropo path further northwards.

As usual, the limiting factor on the higher amateur bands is activity.


73 from Ian GM3SEK


Richard GD8EXI
 

The >3000Km sea path between GD and EA8 is open about 2 days a year on average at 144MHz. However very few of these openings have extended up to 432MHz and none in recent times have reached 1296MHz.
 
A case in point was September 2013 when I worked EA8 repeatedly on 144MHz and managed a few QSOs on 432MHz but failed completely on 1296MHz in spite of many attempts spread over 2 days.
 
The same frequency dependency occurs with QSOs to Northern Spain and Western France with the path very rarely open above 432MHz.
 
I do not know why these sea paths open less often with increasing frequency and so it may be wrong to assume 10GHz will be worse still.
 
We hope to set up a lighthouse style 10GHz beacon here in GD. We are currently trying to source a second hand ship’s satellite comms system, for the continuously rotating dish in a raydome.

73s
Richard
GD8EXI



On 13/01/2015 09:25, "'Ian White' gm3sek@... [ukmicrowaves]" <ukmicrowaves@...> wrote:

 
>
>Having a sea path is one thing, but has there ever been evidence of a duct
>that far north?  Still I will be in North Gran Canaria later in the year....
>
>Roger
>G8CUB

On 2m, yes, and I believe on 70cm also. Unfortunately those contacts have been displaced from the record tables by more recent longer contacts, so they are in danger of becoming lost.

At higher frequencies, I've had the phone go off in my pocket with a "Welcome" text from Jersey. That is not a sea path to SW Scotland so aircraft scatter might also have been involved; but that is another valid possibility to extend a long tropo path further northwards.

As usual, the limiting factor on the higher amateur bands is activity.

73 from Ian GM3SEK

 
   



Roger Ray
 

Dave,

According to the info I had from Manel EA3FLX, there was no special authorization required for the 10GHz SSB segmnent, certainly in mainland Spain.
The Italy to Madeira 10GHz attempt for later this year iincludes visiting groups operating in Spain near Gibraltar.

Roger


---In ukmicrowaves@..., <zen70432@...> wrote :

On 12/01/2015 10:09, Christopher Bartram cbartram@...
[ukmicrowaves] wrote:
> I was trying to generate interest in EA8
> for tests on 10GHz, but at that time, despite some interest, EAs weren't
> licenced for the band, and, understandably, nobody wanted to try. Now
> there is both interest and activity on the Canaries, the potential
> exists for a GM-EA8 world record ...

Chris,

The biggest problem is getting a microwave licence down there, I and
several other emers have spent years trying to get a licence for years.
The current conditions are here:

http://www.ure.es/english/general-information/417-licensing-and-basic-info-for-visitor-hams-.html

73 Dave G4RGK


marcuswalden@...
 

Richard,

 

Assuming that you are talking about 3 September 2013 (VHF/UHF column in RadCom November 2013), I looked at some radiosonde data at 1200 UTC for this date.

 

There was an elevated duct over Camborne (UK) with its top at ~770 m and a depth of ~350 m that might support frequencies down to ~37 MHz. Above Funchal (Madeira), the elevated duct top was at ~640 m with a depth of ~140 m, while above Guimar (Tenerife) the top was at ~950 m and its depth was ~600 m.

 

From this radiosonde data, one might assume that there was a continuous elevated duct extending from the UK to the Canary Islands, albeit one where the characteristics changed with distance.


Weather charts for this time period indicate a high pressure system over the Bay of Biscay, which suggests the elevated duct was a subsidence duct.

 

I believe your station is at ~60 m altitude so there would have been a sizeable coupling loss into the elevated duct (~60 dB?). There might have been sufficient link budget to establish a contact on 430 MHz but the additional loss at 1296 MHz could just have been too much.


How do the conducted powers and antenna gains for your system compare at 430 MHz and 1296 MHz?


Do you know the station details at the other end of the link?


If you and/or the other station had been closer to or within the duct, the coupling losses would have been much lower. I wonder if you then might also have established the contact at 1296 MHz or even higher frequencies. Obviously, there are physical/practical limitations to getting the station higher to take advantage of these elevated ducts.

Hope this is of interest.

 

Marcus G0IJZ


Richard GD8EXI
 

Marcus
Thank you for the information.
The last time I tried contacting EA8 on 1296MHz was indeed during the opening of the 3rd Sept 2013 as reported in Radcom.
On 144 and 432MHz I was running 400 watts at the antenna with 15.0 and 18.4dBd of antenna gain respectively. On 1296MHz at that time I was running about 300 watts at the antenna with 18.8dBd of antenna gain, so the three stations were quite similar in terms of erp.
 
I am afraid I did not take notes as to the equipment at the other end however I do remember the stations were running a lot less power on 1296MHz so I was expecting a possible one way contact using 70cms for talk back but it did not happen. The reports on 432MHz were in the 4.2 to 5.5 range so quite weak. So it could just be that the 1296MHz signals were below the threshold because of poor coupling into the duct as you said.
 
I am indeed at 60metres ASL and with the ground rising to 160metres 3Kms away on the bearing of 203 deg to EA8. So far from an ideal take off at this end probably causing significant extra loss.
 
My general observation is that the sea paths to EA8 or NW mainland Spain do tend to show a marked frequency dependence in contrast to the tropo path to HB9 where I can often move up band by band to 1296MHz with similar reports on each band.
 
Recent examples being 30/12/2014 and 5/1/2015 when I had 13 QSOs on 144 and 432MHz over 1000Kms to SW France and Northern Spain but no successful QSYs up to 1296MHz.
 
This is just anecdotal evidence and what is needed is a systematic study of beacon strengths across the different band over a long period.
 
With the advent SDR receivers it should be possible to monitor multiple beacon frequencies logging the signal to noise ratio against time. Has anybody tried this or know of any software to do it?
 
 
73s
Richard
GD8EXI



On 14/01/2015 20:06, "marcuswalden@... [ukmicrowaves]" <ukmicrowaves@...> wrote:

 
 
 
   

Richard,
 
Assuming that you are talking about 3 September 2013 (VHF/UHF column in RadCom November 2013), I looked at some radiosonde data at 1200 UTC for this date.
 
There was an elevated duct over Camborne (UK) with its top at ~770 m and a depth of ~350 m that might support frequencies down to ~37 MHz. Above Funchal (Madeira), the elevated duct top was at ~640 m with a depth of ~140 m, while above Guimar (Tenerife) the top was at ~950 m and its depth was ~600 m.
 
From this radiosonde data, one might assume that there was a continuous elevated duct extending from the UK to the Canary Islands, albeit one where the characteristics changed with distance.


Weather charts for this time period indicate a high pressure system over the Bay of Biscay, which suggests the elevated duct was a subsidence duct.

 
I believe your station is at ~60 m altitude so there would have been a sizeable coupling loss into the elevated duct (~60 dB?). There might have been sufficient link budget to establish a contact on 430 MHz but the additional loss at 1296 MHz could just have been too much.


How do the conducted powers and antenna gains for your system compare at 430 MHz and 1296 MHz?


Do you know the station details at the other end of the link?

If you and/or ! the other station had been closer to or within the duct, the coupling losses would have been much lower. I wonder if you then might also have established the contact at 1296 MHz or even higher frequencies. Obviously, there are physical/practical limitations to getting the station higher to take advantage of these elevated ducts.
Hope this is of interest.
 
Marcus G0IJZ

 
   



Brian Howie <brian@...>
 

In message <00b201d02eaf$0ce40910$26ac1b30$@co.uk>, "'Ian White' gm3sek@... [ukmicrowaves]" <ukmicrowaves@...> writes
GW4DGU wrote:


It's worth noting that there seems to be an unobstructed oversea
great-circle path from Southerness, on the Solway, to the northern end
of Tenerife. Several years ago, I was trying to generate interest in EA8
for tests on 10GHz, but at that time, despite some interest, EAs weren't
licenced for the band, and, understandably, nobody wanted to try. Now
there is both interest and activity on the Canaries, the potential
exists for a GM-EA8 world record ...
West of Southerness the path becomes blocked by the Isle of Man, but it resumes again on the eastern shore of Luce Bay, close to where the historic 10GHz QSOs were made to St David's Head. This more westerly path to EA8 is actually better than the easterly path because it includes the entire north shore of Tenerife and most of the north shore of Gran Canaria too.

From the home QTH, I have all but the last 5km...
I wrote to GM3OXX asking about the world record about a year ago. I wanted to know where the Portpatrick end was exactly. I had originally got the impression it was from Auchenmalg Bay.

It was done on 10mW with fairly small dishes. They used no talk-back as 2m wouldn't work over the path. With a bit more power and SSB EA8 would be workable on 10GHz

He sent me some pictures which I've put on flikr.

https://www.flickr.com/photos/29874435@N04/sets/72157647987609173/

73 Brian GM4DIJ

--
Brian Howie


Chris
 

Hi George GM3OXX gave me the 10GHz rig that he used for the record,I still have it and it still works
Chris GM4YLN

On 15/01/2015 20:55, Brian Howie brian@... [ukmicrowaves] wrote:

In message <00b201d02eaf$0ce40910$26ac1b30$@co.uk>, "'Ian White'
gm3sek@... [ukmicrowaves]"
writes
>GW4DGU wrote:
>
>>
>>It's worth noting that there seems to be an unobstructed oversea
>>great-circle path from Southerness, on the Solway, to the northern end
>>of Tenerife. Several years ago, I was trying to generate interest in EA8
>>for tests on 10GHz, but at that time, despite some interest, EAs weren't
>>licenced for the band, and, understandably, nobody wanted to try. Now
>>there is both interest and activity on the Canaries, the potential
>>exists for a GM-EA8 world record ...
>>
>
>West of Southerness the path becomes blocked by the Isle of Man, but it
>resumes again on the eastern shore of Luce Bay, close to where the
>historic 10GHz QSOs were made to St David's Head. This more westerly
>path to EA8 is actually better than the easterly path because it
>includes the entire north shore of Tenerife and most of the north shore
>of Gran Canaria too.
>
>From the home QTH, I have all but the last 5km...

I wrote to GM3OXX asking about the world record about a year ago. I
wanted to know where the Portpatrick end was exactly. I had originally
got the impression it was from Auchenmalg Bay.

It was done on 10mW with fairly small dishes. They used no talk-back
as 2m wouldn't work over the path. With a bit more power and SSB EA8
would be workable on 10GHz

He sent me some pictures which I've put on flikr.

https://www.flickr.com/photos/29874435@N04/sets/72157647987609173/

73 Brian GM4DIJ

--
Brian Howie



Christopher Bartram <cbartram@...>
 

Brian, and Chris,

<I wrote to GM3OXX asking about the world record about a year ago. I wanted to know where the Portpatrick end was exactly. I had originally got the impression it was from Auchenmalg Bay. It was done on 10mW with fairly small dishes. They used no talk-back as 2m wouldn't work over the path. With a bit more power and SSB EA8 would be workable on 10GHz He sent me some pictures which I've put on flikr.


Thanks for jogging my memory! I had it in my mind that the southern terminal of the 'OXX - 'BRS path was Porthmeor Beach near St.Ives, but have subsequently realised that I was confusing things with tests run by Ed, G3VPF and Phil, GW3PPF at another time. Back in the early '80s, I used Pendeen Watch for over-the-horizon WB tests on 10GHz with G4SJP/P at Hartland Quay.

Vy 73

Chris
GW4DGU


Tony G4NBS
 

Not sure if this will work but August 1973 Radcom reported OXX QSO with NGR. Saw this by chance as it had been kept as part of GB3PI records!

Hopefully attachment for interest works.

73
Tony G4NBS

From: "Brian Howie brian@... [ukmicrowaves]"
To: ukmicrowaves@...
Sent: Thursday, 15 January 2015, 20:55
Subject: Re: [ukmicrowaves] 10GHz World Record
 
In message <00b201d02eaf$0ce40910$26ac1b30$@co.uk>, "'Ian White'
gm3sek@... [ukmicrowaves]"
writes
>GW4DGU wrote:
>
>>
>>It's worth noting that there seems to be an unobstructed oversea
>>great-circle path from Southerness, on the Solway, to the northern end
>>of Tenerife. Several years ago, I was trying to generate interest in EA8
>>for tests on 10GHz, but at that time, despite some interest, EAs weren't
>>licenced for the band, and, understandably, nobody wanted to try. Now
>>there is both interest and activity on the Canaries, the potential
>>exists for a GM-EA8 world record ...
>>
>
>West of Southerness the path becomes blocked by the Isle of Man, but it
>resumes again on the eastern shore of Luce Bay, close to where the
>historic 10GHz QSOs were made to St David's Head. This more westerly
>path to EA8 is actually better than the easterly path because it
>includes the entire north shore of Tenerife and most of the north shore
>of Gran Canaria too.
>
>From the home QTH, I have all but the last 5km...

I wrote to GM3OXX asking about the world record about a year ago. I
wanted to know where the Portpatrick end was exactly. I had originally
got the impression it was from Auchenmalg Bay.

It was done on 10mW with fairly small dishes. They used no talk-back
as 2m wouldn't work over the path. With a bit more power and SSB EA8
would be workable on 10GHz

He sent me some pictures which I've put on flikr.

https://www.flickr.com/photos/29874435@N04/sets/72157647987609173/

73 Brian GM4DIJ

--
Brian Howie