Date   

Re: Ofcom RF Exposure limits proposal

Mark GM4ISM
 

This will present a bit of a challenge to Ofcom  in policing and a challenge to our community in providing the evidence that we are compliant.

Amateur antenna systems are often rotatable and  a simple distance calculation will not suffice if in some directions there are  obstacles (eg trees between the antenna system and  people)  That is hard to calculate with any accuracy.

Not to mention that for many amateur lower frequency systems we are talking about near-field calculations in reality.

 

I can see that the only way to  prove compliance would be with prohibitively  expensive calibrated field strength measuring equipment with a degree of training in its operation (Most are E Field and notoriously inaccurate when measurements are taken too close to any object, reading significantly high  near metalwork)  A Nardalert going off for example, does not necessarily mean you have exceeded  the RF exposure level.

I would hope that  we wont need this level of proof, and that calculation by an approved method will suffice.

 

The one thing in our favour is the time averaging. The footnotes in ICNIRP Guidance  state that the basic restriction level is an average over 6 minutes. Given a 50% Tx Rx duty cycle we should  normally not be forced to adopt the  basic restriction tabulated values as LIMITS.  For some modes, like SSB and CW the actual mean power is lower that the peak power during the transmission period.

 

That said, let us not forget that RF exposure is a safety issue and is also highly emotive in the public domain, and there is a lot of mis-information out there.   Never use the word Radiation... 

We should already be operating  such that we do not exceed ICNIRP basic restrictions for our neighbours or ourselves.

In most circumstances it is likely that this is already the case  but it seems like we will need to be able to demonstrate this.

 

So, Murray and others in the RSGB.. I think you have a real challenge to prove the RSGSs worth by working with OFCOM to  provide  practical guidance, approved calculation methods and perhaps even rentable hazard meters  that could be used by UK amateurs to satisfy Ofcom’s requirements.

Reading the consultation paper, I don’t think that  they are going to water this down for Amateur radio.

 

I work in this field (pun intended)  and have a good deal of experience in RF field strength measurements,  issues with ICNIRP compliance and demonstration of this.  Its not easy to do this in the professional world but at least I have access to professional hazard meters etc.

 

I am not presently a member of the RSGB (I wont go into why here)  but I am willing to  offer my knowledge and experience in this area if that will assist.

 

Mark GM4ISM

 

 

 

 

 

Sent from Mail for Windows 10

 

From: Murray Niman
Sent: 22 February 2020 00:26
To: UKMicrowaves@groups.io
Subject: [UKMicrowaves] Ofcom RF Exposure limits proposal

 

GB2RS refers to the new Ofcom consultation on RF Exposure/Safety at

 

 

The small print of the proposed new licence condition/guidance as broadly drafted at the rear is all encompassing (and potentially quite impractical) for any thing and any licensee with >10W eirp. 

Watch out....

   Murray G6JYB


 


Re: Ofcom RF Exposure limits proposal

Neil Smith G4DBN
 

It’s an OWA redirect link. Just use cut and paste on the text. Pandering to pseudo-science and the gutter press and the uneducated. Ofcom are in a cleft stick, but at least they are pinning it on PHE to make up some numbers. This should be a candidate for a post-Brexit bonfire of regulations, but Public Opinion as imagined by politicians will probably give it wings. The buggers want to stop me growing trees to burn to heat my house, stop me driving, stop me putting up aerials and now make it harder to play on the radio. Going to turn me into a mad Prepper at this rate.
Neil G4DBN

On 22 Feb 2020, at 09:57, Peter Torry via Groups.Io <peter.torry@...> wrote:

Morning all,

The link referred to takes me directly to Ofcom wheter I click on it or cut and paste - very strange.

73

Peter  G3SMT



On 22/02/2020 09:45, Chris Bartram G4DGU wrote:

Hello Murray

I went to that URL, and was greeted by a window asking me to provide a third-party Company with information which I have no wish to share with that organisation. So, I have been unable to read the Ofcom consultation. I'll try approaching the problem by another route, but I shouldn't have to ...

73

Chris G4DGU


On 22/02/2020 00:26, Murray Niman wrote:
GB2RS refers to the new Ofcom consultation on RF Exposure/Safety at
 
 
The small print of the proposed new licence condition/guidance as broadly drafted at the rear is all encompassing (and potentially quite impractical) for any thing and any licensee with >10W eirp. 

Watch out....

   Murray G6JYB




Re: Ofcom RF Exposure limits proposal

Josh Murray
 



On Sat, 22 Feb 2020 at 10:04, Andy G4JNT <andy.g4jnt@...> wrote:

On Sat, 22 Feb 2020 at 09:57, Peter Torry via Groups.Io <peter.torry=talktalk.net@groups.io> wrote:

Morning all,

The link referred to takes me directly to Ofcom wheter I click on it or cut and paste - very strange.

73

Peter  G3SMT



On 22/02/2020 09:45, Chris Bartram G4DGU wrote:

Hello Murray

I went to that URL, and was greeted by a window asking me to provide a third-party Company with information which I have no wish to share with that organisation. So, I have been unable to read the Ofcom consultation. I'll try approaching the problem by another route, but I shouldn't have to ...

73

Chris G4DGU


On 22/02/2020 00:26, Murray Niman wrote:
GB2RS refers to the new Ofcom consultation on RF Exposure/Safety at
 
 
The small print of the proposed new licence condition/guidance as broadly drafted at the rear is all encompassing (and potentially quite impractical) for any thing and any licensee with >10W eirp. 

Watch out....

   Murray G6JYB



--
Peter G3SMT

--
Many Thanks

Best Regards

Josh Murray


Re: Ofcom RF Exposure limits proposal

Andy G4JNT
 


On Sat, 22 Feb 2020 at 09:57, Peter Torry via Groups.Io <peter.torry=talktalk.net@groups.io> wrote:

Morning all,

The link referred to takes me directly to Ofcom wheter I click on it or cut and paste - very strange.

73

Peter  G3SMT



On 22/02/2020 09:45, Chris Bartram G4DGU wrote:

Hello Murray

I went to that URL, and was greeted by a window asking me to provide a third-party Company with information which I have no wish to share with that organisation. So, I have been unable to read the Ofcom consultation. I'll try approaching the problem by another route, but I shouldn't have to ...

73

Chris G4DGU


On 22/02/2020 00:26, Murray Niman wrote:
GB2RS refers to the new Ofcom consultation on RF Exposure/Safety at
 
 
The small print of the proposed new licence condition/guidance as broadly drafted at the rear is all encompassing (and potentially quite impractical) for any thing and any licensee with >10W eirp. 

Watch out....

   Murray G6JYB



--
Peter G3SMT


Re: Ofcom RF Exposure limits proposal

Peter G3SMT
 

Morning all,

The link referred to takes me directly to Ofcom wheter I click on it or cut and paste - very strange.

73

Peter  G3SMT



On 22/02/2020 09:45, Chris Bartram G4DGU wrote:

Hello Murray

I went to that URL, and was greeted by a window asking me to provide a third-party Company with information which I have no wish to share with that organisation. So, I have been unable to read the Ofcom consultation. I'll try approaching the problem by another route, but I shouldn't have to ...

73

Chris G4DGU


On 22/02/2020 00:26, Murray Niman wrote:
GB2RS refers to the new Ofcom consultation on RF Exposure/Safety at
 
 
The small print of the proposed new licence condition/guidance as broadly drafted at the rear is all encompassing (and potentially quite impractical) for any thing and any licensee with >10W eirp. 

Watch out....

   Murray G6JYB



--
Peter G3SMT


Re: Ofcom RF Exposure limits proposal

Andy G4JNT
 

Yes, the link posted is not what it says.

Either copy and paste as text, that works, or use the tinyURL one given in the GB2RS article


On Sat, 22 Feb 2020 at 09:46, John Worsnop <johnworsnop@...> wrote:
What's the strange link Murray? Takes me to something about Outlook?


On Sat, 22 Feb 2020, 00:26 Murray Niman, <g6jyb@...> wrote:
GB2RS refers to the new Ofcom consultation on RF Exposure/Safety at
 
 
The small print of the proposed new licence condition/guidance as broadly drafted at the rear is all encompassing (and potentially quite impractical) for any thing and any licensee with >10W eirp. 

Watch out....

   Murray G6JYB




Re: Ofcom RF Exposure limits proposal

John Worsnop
 

What's the strange link Murray? Takes me to something about Outlook?


On Sat, 22 Feb 2020, 00:26 Murray Niman, <g6jyb@...> wrote:
GB2RS refers to the new Ofcom consultation on RF Exposure/Safety at
 
 
The small print of the proposed new licence condition/guidance as broadly drafted at the rear is all encompassing (and potentially quite impractical) for any thing and any licensee with >10W eirp. 

Watch out....

   Murray G6JYB




Re: Ofcom RF Exposure limits proposal

Chris Bartram G4DGU
 

Hello Murray

I went to that URL, and was greeted by a window asking me to provide a third-party Company with information which I have no wish to share with that organisation. So, I have been unable to read the Ofcom consultation. I'll try approaching the problem by another route, but I shouldn't have to ...

73

Chris G4DGU


On 22/02/2020 00:26, Murray Niman wrote:
GB2RS refers to the new Ofcom consultation on RF Exposure/Safety at
 
 
The small print of the proposed new licence condition/guidance as broadly drafted at the rear is all encompassing (and potentially quite impractical) for any thing and any licensee with >10W eirp. 

Watch out....

   Murray G6JYB



Ofcom RF Exposure limits proposal

Murray Niman
 
Edited


A better attempt with links etc - 

GB2RS
refers to the new Ofcom consultation on RF Exposure/Safety at
https://rsgb.org/main/blog/news/gb2rs/headlines/2020/02/21/ofcom-consults-on-emf-exposure/ 
and
 
The small print of the proposed new licence condition/guidance as broadly drafted at the rear is all encompassing (and potentially quite impractical) for any thing and any licensee with >10W eirp. 

Watch out....

AND
This stuff even cropped up in WRC process last year via some other countries, so its not just tin hats and nimbys 

   Murray G6JYB




Re: small(ish) 23cm amp wanted

Martin Phillips G4CIO
 

I've got an unbuilt BAO amp which could be available as I've recently bought a SGLabs unit. Contact me offline...

Martin/


On 21 February 2020 12:26:32 GMT, "G0FVI via Groups.Io" <Andrew.gilfillan@...> wrote:
Hi all,
anyone got a 23cm amp in the range of 30-50 watt they would like to sell, or alternatively anyone willing to fabricate a PCB for me for Jon G4BAO's design
(published 'microwave know how'), will pay of course!

Andy G0FVI

--
Martin Phillips


Mystery MMIC

Chris Bartram G4DGU
 

Mike and Mike,

Thank you both for you comments. The device turned-out to be a now obsolete Sirenza SNA586 which I'd bought for a work job about 15years ago! It is still very usable, and I have enough to be comfortable using the parts for projects of my own.

73

Chris G4DGU


Re: Réf. : [UKMicrowaves] Mystery MMIC

Chris Bartram G4DGU
 

Francois

Thank you for your reply. You have managed to trigger the correct part of my brain, and I am now able to remember the job which they were used on! They are the Sirenza device and will be useful for future projects of my own.

Best 73

Chris G4DGU

On 21/02/2020 09:34, F1CHF wrote:


Re: small(ish) 23cm amp wanted

ian hope (2E0IJH)
 

SG Labs do a Matching 25w unit for there transverters with 2w in 25w out, with a inbuilt pre-amp and relays.
 
 
Last one I bought was around 140 euros, but you would need to ask current price.
 
Worth a consideration
 
Ian
2E0IJH
 

 
 
Sent: Friday, February 21, 2020 at 12:26 PM
From: "G0FVI via Groups.Io" <Andrew.gilfillan@...>
To: UKMicrowaves@groups.io
Subject: [UKMicrowaves] small(ish) 23cm amp wanted
Hi all,
anyone got a 23cm amp in the range of 30-50 watt they would like to sell, or alternatively anyone willing to fabricate a PCB for me for Jon G4BAO's design
(published 'microwave know how'), will pay of course!

Andy G0FVI


small(ish) 23cm amp wanted

G0FVI
 

Hi all,
anyone got a 23cm amp in the range of 30-50 watt they would like to sell, or alternatively anyone willing to fabricate a PCB for me for Jon G4BAO's design
(published 'microwave know how'), will pay of course!

Andy G0FVI


Re: Italian text - can anyone translate

G3UVR Denis IO83KH
 

John.
Thanks for the pictures and thanks to others for ideas to follow up on.

73 de Denis G3UVR


Réf. : [UKMicrowaves] Mystery MMIC

F1CHF
 

I found SNA286
but not sure for the micro-X box
see here
 
francois
 
 
 
 
 
-------Message original-------
 
Date : 21/02/2020 09:43:21
Sujet : [UKMicrowaves] Mystery MMIC
 
I have a mystery strip of (presumably) MMICs in a plastic micro-X SMD
package. Does anyone recognise the package code S5? This looks like a
Minicircuits part. I've checked their web site, and looked at the usual
Codebooks (Tnx, Roger!) but I can't find any clue as to what the part
is. I suspect it's a now obsolete device, but it would be good to be
proven wrong.
 
Does anyone here have any info?
 
73
 
Chris G4DGU
 
 
 


Re: Mystery MMIC

Michael Scott
 

Hi Chris

The chipbank has some MSA0504s and they are marked 5 with a dot marking the input lead. The ones I have are in Avantek packs.

73, Mike, G3LYP

-----Original Message-----
From: Chris Bartram G4DGU
Sent: Friday, February 21, 2020 8:43 AM
To: UKMicrowaves@groups.io
Subject: [UKMicrowaves] Mystery MMIC

I have a mystery strip of (presumably) MMICs in a plastic micro-X SMD
package. Does anyone recognise the package code S5? This looks like a
Minicircuits part. I've checked their web site, and looked at the usual
Codebooks (Tnx, Roger!) but I can't find any clue as to what the part
is. I suspect it's a now obsolete device, but it would be good to be
proven wrong.

Does anyone here have any info?

73

Chris G4DGU


Re: scope knobs?

dave cossar
 

Hi ,

It's OK  glad to help they are from my Techtronics 465 which I stored in the shed

EHT  failed ! wise after the event now

will post today

Dave GM3WIL

On 20 February 2020 at 22:30 "militaryoperator via Groups.Io" <Military1944@...> wrote:

Yes, just 2 needed Dave. Let me know total with postage. 

B Nock
47 Oakfield Rd
Kidderminster
Worcs DY11 6PL


cheers


-----Original Message-----
From: dave cossar via Groups.Io <davecossar@...>
To: UKMicrowaves <UKMicrowaves@groups.io>
Sent: Thu, 20 Feb 2020 21:27
Subject: Re: [UKMicrowaves] scope knobs?

looks good then  is two enough?

On 20 February 2020 at 20:05 "militaryoperator via Groups.Io" <Military1944@...> wrote:

Hi Ben ,
I have found my Tec 465 got two red knobs  red marked VAR   for the Y input
is that what you wanted?

Dave GM3WIL


Colour and lettering immaterial Dave so long as they are tiny shaft, 3mm !! hi.


Ben
 
 


Re: Mystery MMIC

Mike Willis
 

5 dB attenuator?
--
Mike G0MJW


Mystery MMIC

Chris Bartram G4DGU
 

I have a mystery strip of (presumably) MMICs in a plastic micro-X SMD package. Does anyone recognise the package code S5? This looks like a Minicircuits part. I've checked their web site, and looked at the usual Codebooks (Tnx, Roger!) but I can't find any clue as to what the part is. I suspect it's a now obsolete device, but it would be good to be proven wrong.

Does anyone here have any info?

73

Chris G4DGU