Date   

Re: Ofcom deadline approaching (next Monday July 22nd)

Michael Scott
 

Hi Murray and others.
 
Folowing the useful discussion session at Finningley, I have just submitted my response online.
 
73, Mike, G3LYP

----- Original Message -----
From: g6jyb
Sent: Thursday, July 18, 2013 11:35 AM
Subject: [ukmicrowaves] Re: Ofcom deadline approaching (next Monday July 22nd)

 


For those who dont like the online form, a MS-Word Template is on the UKuG home page if you look at the latest update there

Murray

--- In ukmicrowaves@..., "g8gtz" wrote:
>
> All,
>
> Just a reminder that the closing date for the Ofcom 2.3 Ghz consultation process is approaching.
>
> I believe that everyone, whether active on 2.3 Ghz or not should respond, as we need to show Ofcom that we value the spectrum we have access to.
>
> If they do not see a large response, they will be more inclined when considering the future of other bands, such as 10 GHz, to take the approach of the authorities in Sweden and Australia and just remove our access to bands without consultation.
>
> In order to encourage responses from the ATV community, who are particularly affected by the proposed changes, I have posted my own proposed responses on the BATC forum at http://www.batc.org.uk/forum/viewtopic.php?f=2&t=3176&start=10
>
> Chris GW4DGU has also published his responses in the latest issue of Scatterpoint.
>
> Thanks to the good work by Murray and others we do have a good relationship with our regulator in the UK and this is the opportunity for us all to show them how much we value the spectrum we have access to.
>
> 73
>
> Noel - G8GTZ
>


Re: CCX 3cms - on or off - not CW

John Fell
 

I also have not seen CCX for several weeks , but it needs some rain along the path to pop up above noise and its been 30C a lot and very dry for July so far .Prepare for flooding .........

73
John 
G0API


On Fri, Jul 19, 2013 at 12:04 PM, g3vkv <g3vkv@...> wrote:
 

Hi John, that one has been fixed some time ago, the GB3UK repeater antenna has been moved to another corner of the mast, will see if I can find out more info - perhaps it doesn't like the heat, CCX is way down in strength here, maybe the PA has gone, it would only take a few milliwatts to be the strength it is here at 4km. 73 Graham

--- In ukmicrowaves@..., "usuallyqrt" wrote:
>
> CCX 3cms had a fault some time back where it would go off if the 70cm repeater was on. Easy to check if the 70cms is on and the beacon is off thats it. Or fire up the repeater and see if CCX goes off. Not seen anything reported that its been fixed. I dont hear CCX at ohm so unable to check this out myself. 73s John.
>



Re: CCX 3cms - on or off - not CW

Graham G3VKV
 

Hi John, that one has been fixed some time ago, the GB3UK repeater antenna has been moved to another corner of the mast, will see if I can find out more info - perhaps it doesn't like the heat, CCX is way down in strength here, maybe the PA has gone, it would only take a few milliwatts to be the strength it is here at 4km. 73 Graham

--- In ukmicrowaves@yahoogroups.com, "usuallyqrt" <usuallyqrt@...> wrote:

CCX 3cms had a fault some time back where it would go off if the 70cm repeater was on. Easy to check if the 70cms is on and the beacon is off thats it. Or fire up the repeater and see if CCX goes off. Not seen anything reported that its been fixed. I dont hear CCX at ohm so unable to check this out myself. 73s John.


G100RSGB -underwhelmed with uWave QSOS

g4bao
 

Come on UKmicrowavers! G100RSGB has been ready with 23 and 3cms gear and so far, above 1GHz we have had two 3cms and 6 23cms QSOs. Almost no UK 3cms stations logged in to KST yesterday, compared to tens in France, and no sked requests via the 6 and 2m stations.
Give me something positive to report in GHz bands. Email me direct for skeds. Note we only have takeoff N to W on 3cms, but 23cms all round.

73
John


Re: Agilent 346A and N9069A reading high?

Mike Willis
 

John Makes a good point - NF meters can typically measure in bandwidths of several MHz and are assuming the noise figure, gain and match is constant across this bandwidth.

When you design a preamp for VHF it is normally a good idea to make it narrow band, especially in the UK where we have very strong pager signals either side of 144MHz. To a DXer, there is nothing of importance outside the 144-145MHz range and a preamp may have a 3dB bandwidth of 2MHz or less to cover this range plus a bit. What this means depends on the filter shape and the NF meter bandwidth, but its quite possible to be missing nearly half the noise due to the filter.

As John says this will mean the ENR calibration won't be right so the difference between noise on and off will be lower than expected resulting in a higher recorded noise figure. You can fix this with a filter which is difficult, or by doing the maths if you know the relative bandwidths, which may be easier.

The negative noise figure issues is probably just noise. If you expect to get better than 0.1dB accuracy after calibration you will need to be very careful, do a lot of integrating and keep everything at a constant temperature and do it all in a screened room. You should see a mean value of zero. The fact it is reading -0.1dB consistently could just be the instrument needs recalibrating, or maybe you have not got the settings right for temperature, or indicate external noise is getting into it from local RF sources and disturbing the calibration. If you are doing this at home I would go with the QRM. Since they installed a mobile phone mast at RAL near the RF lab, we haven't been able to measure VHF/UHF noise figures accurately in the RF lab.

Mike

--- In ukmicrowaves@yahoogroups.com, G3XDY <g3xdy@...> wrote:

Hi Conrad

I have also seen abnormally high NF readings on an example of the HA8ET
preamp. This preamp includes narrow band filtering, and it could be that
the noise bandwidth of the preamp is narrower than the Agilent test set
bandwidth. I recollect that you might be able to configure the Agilent
box for a narrower measurement bandwidth, but I don't have the manual to
check. The 8970A will suffer from the same problem and is not
configurable, the only way to test such preamps with the 8970 series
boxes is to build a low loss narrow band 144MHz filter, then calibrate
the instrument with the filter in circuit and then test the preamp via
the filter (bear in mind that the filter won't look like a flat 50 ohm
source so there will be errors due to changes in the impedance seen by
the preamp input unless you include an isolator after the filter).

73

John G3XDY


On 18/07/2013 13:44, Conrad Farlow wrote:
I have access to an Agilent 346A head with an N9069A noise figure
measurement application running on an EXA series spectrum analyser. It
seems to have number of issues.

1. After calibration the noise figure and gain are never truly zero, the
noise figure normally reads -0.1 or similar and the gain will be -0.15
or thereabouts, these are just typical figures.

2.When I measure noise figure I see good results on the gain but the
noise figure seems high. For instance my HA8ET Extra 2 LNA reads about
1.4dB whereas I am pretty sure that it is much better than this.

I have Tcold set to the temperature on the surface of the device as
measured by a thermocouple. I have used some loss compensation before
the device, I have generously allowed 0.1 dB for a high quality
female-female N type.

Does anyone have any advice as to what is going wrong? I do have an 8970
that I could use for a reference check but it hasn't been switched on
for a while, shocking I know.......

Bit puzzled..


Re: Agilent 346A and N9069A reading high?

John Quarmby
 

Hi Conrad

I have also seen abnormally high NF readings on an example of the HA8ET preamp. This preamp includes narrow band filtering, and it could be that the noise bandwidth of the preamp is narrower than the Agilent test set bandwidth. I recollect that you might be able to configure the Agilent box for a narrower measurement bandwidth, but I don't have the manual to check. The 8970A will suffer from the same problem and is not configurable, the only way to test such preamps with the 8970 series boxes is to build a low loss narrow band 144MHz filter, then calibrate the instrument with the filter in circuit and then test the preamp via the filter (bear in mind that the filter won't look like a flat 50 ohm source so there will be errors due to changes in the impedance seen by the preamp input unless you include an isolator after the filter).

73

John G3XDY

On 18/07/2013 13:44, Conrad Farlow wrote:
I have access to an Agilent 346A head with an N9069A noise figure
measurement application running on an EXA series spectrum analyser. It
seems to have number of issues.

1. After calibration the noise figure and gain are never truly zero, the
noise figure normally reads -0.1 or similar and the gain will be -0.15
or thereabouts, these are just typical figures.

2.When I measure noise figure I see good results on the gain but the
noise figure seems high. For instance my HA8ET Extra 2 LNA reads about
1.4dB whereas I am pretty sure that it is much better than this.

I have Tcold set to the temperature on the surface of the device as
measured by a thermocouple. I have used some loss compensation before
the device, I have generously allowed 0.1 dB for a high quality
female-female N type.

Does anyone have any advice as to what is going wrong? I do have an 8970
that I could use for a reference check but it hasn't been switched on
for a while, shocking I know.......

Bit puzzled..


CCX 3cms - on or off - not CW

usuallyqrt <usuallyqrt@...>
 

CCX 3cms had a fault some time back where it would go off if the 70cm repeater was on. Easy to check if the 70cms is on and the beacon is off thats it. Or fire up the repeater and see if CCX goes off. Not seen anything reported that its been fixed. I dont hear CCX at ohm so unable to check this out myself. 73s John.


Re: Two part adhesive (OT)

Chris G8BKE
 

And not nearly as good as true Araldite which can still be bought on eBay!

C

--- In ukmicrowaves@yahoogroups.com, Andy Talbot <andy.g4jnt@...> wrote:

When did Araldite become Evo-Stik ?
Same packaging at first sight, same colour packs. Just a name change and
the two tubes placed in the blister pack in opposing directions (and that's
weird)

Confusing us of advancing years ;-)

Andy
'jnt


Re: GB3CCX

Graham G3VKV
 

Hi Keith, CCX is on this morning but I think the power is much reduced
from normal (the site is just above me 4k distant) not reaching full scale on the meter here as usual 73 Graham G3VKV

Thanks Ken, I'll check when I go out /P on Sunday.

73 Keith
GW3TKH





Re: [Moon] [Moon-Net] Agilent 346A and N9069A reading high?

Conrad Farlow <conrad@...>
 

I don't think so. That was merely one example of several preamps that I have that have been measured elsewhere by trustworthy individuals to have much better noise figures. I have a 346B noise head I am going to try that as well.

I was hoping that I was being stupid (I certainly have the capacity for it) and missing something basic.

Conrad

2.When I measure noise figure I see good results on the gain but the
noise figure seems high. For instance my HA8ET Extra 2 LNA reads about
1.4dB whereas I am pretty sure that it is much better than this.
it's all a lot simpler than long convoluted theories....

the pre amp is oscillating

Graham 'MBI 'VHX



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Re: [Moon] [Moon-Net] Agilent 346A and N9069A reading high?

Graham D <graham.d@...>
 

2.When I measure noise figure I see good results on the gain but the
noise figure seems high. For instance my HA8ET Extra 2 LNA reads about
1.4dB whereas I am pretty sure that it is much better than this.
it's all a lot simpler than long convoluted theories....

the pre amp is oscillating

Graham 'MBI 'VHX


Re: GB3CCX

Keith GW3TKH
 

Thanks Ken, I'll check when I go out /P on Sunday.

73 Keith
GW3TKH


From: Ken
To: ukmicrowaves@...
Sent: Wednesday, 17 July 2013, 20:38
Subject: [ukmicrowaves] Re: GB3CCX

 
Present as normal this evening. Of course I can't be sure it was there when you looked as it did disappear for a while recently, and it was warm today.

Ken,
G3YKI

--- In ukmicrowaves@..., Keith Winnard wrote:
>
> I checked the beacons from the top of my local hill this morning. 'CCX
> was absent, usually many strong reflective paths present.
> Has the oscillator stopped again?
>
> 73 Keith
> GW3TKH
>




3cm sked?

gm0icf <gm0icf@...>
 

With the area of high pressure sitting over the UK is anyone interested in a 3cm sked either tomorrow, Friday 19th or Saturday 20th afternoon/evening.
Locator is IO75OP.
cheers,
Bill.


Agilent 346A and N9069A reading high?

Conrad Farlow <conrad@...>
 

I have access to an Agilent 346A head with an N9069A noise figure measurement application running on an EXA series spectrum analyser. It seems to have number of issues.

1. After calibration the noise figure and gain are never truly zero, the noise figure normally reads -0.1 or similar and the gain will be -0.15 or thereabouts, these are just typical figures.

2.When I measure noise figure I see good results on the gain but the noise figure seems high. For instance my HA8ET Extra 2 LNA reads about 1.4dB whereas I am pretty sure that it is much better than this.

I have Tcold set to the temperature on the surface of the device as measured by a thermocouple. I have used some loss compensation before the device, I have generously allowed 0.1 dB for a high quality female-female N type.

Does anyone have any advice as to what is going wrong? I do have an 8970 that I could use for a reference check but it hasn't been switched on for a while, shocking I know.......

Bit puzzled..
--

__________________________________________________

73

Conrad G0RUZ IO93FR


North Wakefield Radio Club

__________________________________________________


Re: UK Microwave Group RSGB Affiliated?

G0DJA <dave@...>
 

--- In ukmicrowaves@yahoogroups.com, "Jules" <jules@...> wrote:

You could always join the RSGB.
They are (were) doing a £1 introductory membership at the mo.
Let's not go into the reasons as my blood pressure might not stand it, but I used to be a member many years ago, but am not now.

I did find a link to an email address to request an affiliated club be added, so I've sent a request.

Not sure how long these things take, but I'll keep going back to look for a few days before using the G-QRP Club option.


Re: Ofcom deadline approaching (next Monday July 22nd)

g6jyb <mjniman@...>
 

For those who dont like the online form, a MS-Word Template is on the UKuG home page if you look at the latest update there

Murray

--- In ukmicrowaves@yahoogroups.com, "g8gtz" <noel@...> wrote:

All,

Just a reminder that the closing date for the Ofcom 2.3 Ghz consultation process is approaching.

I believe that everyone, whether active on 2.3 Ghz or not should respond, as we need to show Ofcom that we value the spectrum we have access to.

If they do not see a large response, they will be more inclined when considering the future of other bands, such as 10 GHz, to take the approach of the authorities in Sweden and Australia and just remove our access to bands without consultation.

In order to encourage responses from the ATV community, who are particularly affected by the proposed changes, I have posted my own proposed responses on the BATC forum at http://www.batc.org.uk/forum/viewtopic.php?f=2&t=3176&start=10

Chris GW4DGU has also published his responses in the latest issue of Scatterpoint.

Thanks to the good work by Murray and others we do have a good relationship with our regulator in the UK and this is the opportunity for us all to show them how much we value the spectrum we have access to.

73

Noel - G8GTZ


Contest next weekend, 21st July

usuallyqrt <usuallyqrt@...>
 

G8ACE will be at Povington SY887811 south coast west of Swanage on Sunday all being well with sun hat 24G 500mW 47G 150mW 76G ?mW 175 T/B I do not intend to linger at this south coast location as the sun will likely be on full heat. If your going to be within reach for a radio contact and have not already emailed me them please email me with your whereabouts to arrange compatible timings. usuallyqrt@yahoo.co.uk 73s John


UK Microwave Group RSGB Affiliated?

Jules G0NZO
 

You could always join the RSGB.
They are (were) doing a 1 introductory membership at the mo.

--- In ukmicrowaves@yahoogroups.com, "G0DJA" <dave@...> wrote:

Hi,

Does anyone know if UKuG is still affiliated to RSGB please?

I'm trying to input my score for UKAC yesterday and UK Microwaves does not seem to be in the list.

The only other option, for me, is G-QRP Club, which is on the list.

Thanks - Dave (G0DJA)


G100RSGB tomorrow

g4bao
 

The camb-hams will be qrv as G100RSGB tomorrow and Thursday. Operation on HF, 6 and 2m plus the rare chance to work the callsign on 1.3 and 10GHz. On 10GHz we just have a dish on a tripod so only have unobstructed takeoff from West through to North. I have already worked g4cbw with the system, so fine for working the UK. 360 degree takeoff on 1.3. Liase via KST.

73
John


Re: 24GHz, 47GHz, and 76-248GHz Contests next weekend, 21st July

John Quarmby
 

Hi Daniel

You would need some exceptional tropo to work the UK on 24GHz from there. The IARU region 1 record on tropo is about 580km. Rainscatter might work, but it you don't often find intense thunderstorms over the sea.

I look forward to a 10GHz QSO soon.

73

John G3XDY

On 16/07/2013 11:34, Daniel Blah wrote:

Hello John et al,

I will be in the north of Germany from next Saturday for a week or so.
The QTH locator will be JO44IJ or thereabout with only water between me and the UK. The closest distance is just under 500kms (Norwich area). Given the lifted conditions predicted by the Hepburn Index Website for Sunday, I was wondering if it would make sense to take 24 GHz with me. My setup is just 300mW to a 30 cms diameter dish. I finished the station 2 weeks ago and have never made a QSO. It looks OK on the bench though.
I was planning to bring my 10 GHz setup, so I have the tripod and the other necessary gimmicks already there. But then again it's holidays in the first place and the car is pretty well packed.
I have no experience with sea ducting and I don't know if it will help on 24 GHz anyway where rising humidity would be rather disturbing, I guess.
The QTH would be either close to the beach or maybe on top of the dyke at 10m asl or so, depending on the tourist density and parking possibility. I need the car battery to power up the station.
I would appreciate to receive some comments before I go into negotiation with my fellow holiday makers.

73s

Daniel
DL3IAE

P.S. I should be around on 10 GHz frequently. Look for me on KST. I have 14W and a 65cm dish.



--- In ukmicrowaves@yahoogroups.com, G3XDY <g3xdy@...> wrote:
I won't be putting together a formal activity list for this event, as I
expect those with the capability to take part are already in touch with
each other to coordinate sites etc, so this is just a reminder that the
UK Microwave group mm wave contest is next Sunday 21st July, from 0900 -
1700z (1000 - 1800 BST).

73

John G3XDY


------------------------------------

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