VERY well done, thanks - now in return, would Ofcom like to require all businesses and households to trace, test and log the interference and electrical pollution from their plasma tellies, dodgy solar panel inverters, wall-warts and other RFI emitting devices?
@g8cykuk3183 жыл бұрын
@John Cliff Long overdue. Maybe we can hold an XR style protest at Ofcim HQ and glue ourselves to the railings until they promise to take (mostly avoidable) domestic RFI seriously . If there was sufficient demand, a cheap RFI track and trace device working with a smartfone could be devised to enable the muggles to self-certify their RFI status ... :-)
@richardbracegirdle61043 жыл бұрын
I think if you read up on the concerns over domestic Smart Meter installations - especially within the USA - you would find it an eye opener.
@patrickmolloy69942 жыл бұрын
Tp be fair, its the manufacturers of the electrical goods.....whether TV or kettle, that have to comply with regulations.
@gcljohn3 жыл бұрын
Useful tool and thanks for this John. I will be performing these calculations, however I consider they will be both bureaucratic and "under duress", all the time that Joe Public is allowed to use 5G iPhones on full duty cycle next to their ears.
@johnrogers99503 жыл бұрын
All licensees who are allowed to transmit above 10WEIRP have to do the assessment. 300,000 in total
@gcljohn3 жыл бұрын
@@johnrogers9950 Thats what the rules say John, but that doesn't make it right.
@collieclone3 жыл бұрын
If this were to make sense, we'd need to fill this out for every band and mode we use, with/without linear, for log-winded, chat QSOs vs. DX hunting short bursts, contests over 48 hours, for every rig we own. Or, somebody somewhere could come to the decision that the whole exercise doesn't make sense whichever way you look at it. This is further proof to me that we live in a literally insane world, but of course I'll comply with it because I'm a law-abiding citizen. This is as idiotic as the signs on the back of vans saying they are limited to 70 mph: Every vehicle in the UK is limited to 70 mph!
@davex7223 жыл бұрын
Every band, yes. Just pick your highest power and heaviest duty mode, if you can meet the requirements, job done.
@andyswain94072 жыл бұрын
Having read the information and done my assessment, I've now virtually shut down any activity, until I can get more thorough guidance. Living in a semi-detached townhouse in a dense estate, with a compact garden, I had discretely and carefully sited a 2m Yagi and small G5RV antenna high in the loft-space to avoid antagonising the neighbours. From what I see in the portrayal of the RSGB calculations, (which seem to assume a garden mast is used), I can only now transmit a feeble signal (at best), even though the antenna is inaccessible and seemingly appropriately distant from the general public, (inc my family). To ensure that this compliance is taken on board by Hams, and that the hobby continues to be viable, greater clarity, advice and examples need to be available. If they already are, it needs to be publicised better. Or, what have I missed that would help solve the issue?
@m0pnn3 жыл бұрын
If the nearest part of the antenna is closest to a person inside the building the antenna is mounted what then? Does this count? That`s the sort of obvious question I need answering. A lot of ops have colinears VHF beams etc mounted below the ridgeline. I must admit this whole process has made me question if can I be arsed anymore. Due to this, I have not operated or bought any new equipment done any construction for months its sucked out all the joy I had for the hobby.
@johnrogers99503 жыл бұрын
for white stick collinear the directivity factor will be more than 6dB for people below the antenna which gives a compliance distance of less than 4m at 400W
@caerffili_callin2 жыл бұрын
Thanks John, very helpful and easy to follow. Just completed my assessmenst using this as a guide and did not take very long at all. Saved all as pdf in a folder on my desktop just in case.
@TheRSGB2 жыл бұрын
Glad the demonstration was helpful.
@alanslaughter163 жыл бұрын
Download this and ran it using Apache Open office. Easy to input your parameters It works just fine. Many thanks to all at the RSGB for their fine efforts! 73 Alan G0KMC
@johnrogers99503 жыл бұрын
Thanks
@M0RMY3 жыл бұрын
Hi John. Thanks for this but I have some genuine concerns. Please define the point of measurement on the antenna. Is it (a) any part of it. (b) the feed point. (c) the centre of mass. Also, if it is a ground-plane antenna does the compliance distance start at the tips of the radials or the feed point? So 3.4m (for example) from the pole or from the periphery of the radial field? Also, people are not always on the ground. Neighbours live/work in upper floors. You are advocating an exercise in creative accounting. None of us (if conscientious) wish to potentially harm ourselves (although it seems that this is deemed OK), our family or the public. However, the multifactorial and non-scientific approach being advocated is disingenuous . I am simply going to write "I rarely transmit, and if I do, it is for very few seconds". That (albeit totally unscientific) seems to tick the "compliance" box. Job done. Why have a regulation that is, by definition, unenforceable due to the transient nature of our hobby radio usage? I have a system "capable" of 1500W continuous RTTY - I won't ever do that because I like to comply with my licence conditions. I still will achieve this aspiration if I write my statement as I suggest. This is the equivalent of an exercise forcing you to state "I have a Ferrari, but I will never drive over 70 mph". Continuous commercial non-ionising radiation at high power is a totally different proposal and this is the aim of the legislation from a H&S angle.
@BoB4jjjjs3 жыл бұрын
Exactly, it is not as simple as it appears. What happens if the window cleaners are round or the builders are working next door or the roofers are there. Do you have to work it out for that as well or do you have to stop transmitting. I am not a Radio Amateur, but I can see lots of problems with this. A big beam aerial/antenna can swing round and get a lot closer to people, what happens with that, where do you take the measurement from? If you have a tall block of flats next door, how on earth do you work that out. It might work as a rough guide, but it is full of holes!
@johnrogers99503 жыл бұрын
It says nearest point of antenna to where the person is is used for compliance distance. Buried Radials are work in progress
@BoB4jjjjs3 жыл бұрын
What about working portable, not many work 100 watts portable, but some do, do you have to work that out as well? As a guide it might work, but how is it going to be enforced with aerials/antennas being changed ever other day with some people? I can see the point if RF is causing a problem, but otherwise, most people have the sense to keep high powered aerials up and away from where it will affect people anyway. I would be the one that would be playing with aerials, does it mean I would have to work this out every time I changed the aerial? All this is putting me off even bothering!
@johnrogers99503 жыл бұрын
@@BoB4jjjjs just do the antenna with highest gain (in each band used) if that is compliant all the others will be. If you are operating say an SES with general public present the safe distance from mast falling over is likely to be much more than that for EMF compliance. If it is just amateurs present in exclusion zones then you are compliant according to Ofcom guidance.
@g4obb3 жыл бұрын
@@johnrogers9950 So are buried people....LOL......my head is fried with BULLSHIT....Jog on....
@davem0udb2 жыл бұрын
I have a 3 storey new build in a village setting with an EFHW running from a 3rd floor bedroom window, I've recalculated all my figures using SSB and my maximum power ranges from 17w on 10m up to a huge 33w on 20m. If the house is empty I can run 100w except on 20m where I can't guarantee anyone will not be outside the house. Its about time the RSGB showed some real world situations, I can't really run more than 10w on FM into a 1.3m collinear. Time to sell up and hand my licence back
@NToombes3 жыл бұрын
So, if I don't comply, do I just sell up now and hand my licence back??
@johnrogers99503 жыл бұрын
No but most people are surprised that already comply particularly with detailed models used for pre-assessed compliance.
@NToombes3 жыл бұрын
@@johnrogers9950 I am sure some people do comply but yet to see an example of a ground fed antenna system in a small back garden with adjoining properties pass this requirement.
@johnharrison57033 жыл бұрын
@@johnrogers9950 over the last 8 months I have been experiment with antenna to minimise noise and VDSL i have tried 14 different antennas and all give me issues and only 1 would comply 20m dipole . But that picks up 59 noise. Urbon amateurs will find it hard to comply and be able to operate. I can't I've been having problems getting out here at any time and now I have to compromise my antenna further and drop power to a useless level. Been testing today with RBN and WSPR and if I drop power to comply I vanish from RBN and WSPR almost gone.
@bill-20183 жыл бұрын
I nearly went out portable today but according to this I would have to assess the location and aerial positions first before operating and fill in the e.m.f. calculator to see if I am compliant and then return another day. Would I have to print it out and carry it to produce it to prove to anyone who asks if I am compliant? All I can say is that my FT817 because it's only 5 Watts I guess it's compliant. G4GHB.
@brian.79663 жыл бұрын
so I take it that when this calculator comes into force ground-mounted verticals, loop antennas, and alike will be useless as they fall outside the safety margin. especially in a small garden. I also think that Ofcom will make an example of someone out there to show a point that they can and will do something, ie a fine.
@johnrogers99503 жыл бұрын
for 20m normally a 4m separation is sufficient look at Ofcom guidance. Remember we have 6 months before the assessments have to be done
@johnharrison57033 жыл бұрын
@@johnrogers9950 I think that is most peoples point. We don't have 4m separation and are unable to move antennas to comply!!! Having 6 months to comply won't make my plot bigger or move it from neighbours.
@philyates40713 жыл бұрын
Could do with the addition of more antenna types, a fair number of amateurs use ground fed wires, as in the inverted L antennas.
@NToombes3 жыл бұрын
Yes please, ground fed inverted L please
@johnrogers99503 жыл бұрын
I could do with more help to prepare them
@iainmeteorscan15553 жыл бұрын
What I can’t understand is why the Calculator is a mish-mash of ERP, EIRP, dBW, dB, dBi and dBd, when all that is required is for all calculations to be made using straight-forward ERP Watts, dB and dBd. If it is necessary for EIRP Watts to be known, then all that is required is for the final ERP Watts calculation to be multiplied by 1.64 to give the required EIRP Watts. Wham bam thank you ma'am (the K.I.S.S. principle).
@johnrogers99503 жыл бұрын
We chose to have 2 columns one for linear quantities and one for logarithmic (dB) Then chose which to use for entry of each individual item, few would be comfortable with entering distance in dBmetres. The units were all added on request following first prototype as was expressing antenna gain in dBi. Peak and average power answers are provided as some quantities have peak limits when Ofcom change over to ICNIRP2020
@iainmeteorscan15553 жыл бұрын
@@johnrogers9950 Thanks for the reply, John. I (and I would think we all) appreciate the amount of work you and colleagues have carried out in formulating the spreadsheet. It’s just that all the differing dBs were doing my head in! I also realise and appreciate that OFCOM wants everything in dBi, maybe to confuse us Hams in the process! Whatever. Well done for the spreadsheet.
@simonrobinson81253 жыл бұрын
Very useful run through thanks
@philyates40713 жыл бұрын
Must agree, was useful to have it explained. Local RSGB rep does not seem at all interested, more a case of I am alright jack.
@2e0evm3 жыл бұрын
Seems straight forward for antennas up a mast ! What about say an inverted L wire which starts 12” off the ground and goes up and then across ?? What are the rules where this is in your own private back yard ??
@chris_hayes3 жыл бұрын
I’d also like to know to use the calculator for antennas fed at ground level.
@johnrogers99503 жыл бұрын
@@chris_hayes you already can if you enter 0.01m for minimum height of antenna. Separation is then all horizontal but is still to be taken from nearest part of antenna in current calculator. Looking at relaxing that following detailed modelling.
@johnharrison57033 жыл бұрын
@@johnrogers9950 i think there is a need for more work in this area. I also feed at ground level due to lack of space. At this time it is impossible to comply and continue with radio.. my antenna and feed point are at the furthest point from my house 43 Feet max. Because garden is triangular that means it is on the fence next to 2 other properties. At 3.4 m and 4.7 m at 10Mhz both my neighbours garden fall inside the exclusion zone. Lots of hams in my area will be in the same or similar situation.
@g4obb3 жыл бұрын
@@johnharrison5703 Tell em you only ever run 1 watt....check my logbook Guv.....oh, sorry we don't have one anymore...too bad!
@evdyo3 жыл бұрын
Very useful video and I just made my first assessment. Apart from compliance, it's a great education tool. 73s DE M0IUR
@TheRSGB3 жыл бұрын
Many thanks. Glad you have found it helpful
@ptonpc3 жыл бұрын
Handy video. Thanks
@johnharrison57033 жыл бұрын
Yes it is simple to use but ground fed antennas and small plots in built up areas are a problem.
@NToombes3 жыл бұрын
Exactly, Inverted L antenna here that's fed from 5ft above the ground in the corner of the garden.
@philyates40713 жыл бұрын
Inverted L fed just above ground point. The RSGB seem to be ignoring ground fed antennas. Especially as there are lot of them about.
@NToombes3 жыл бұрын
@@philyates4071 Yes, they seem to be VERY reluctant in accommodating common antenna systems as maybe they know they will not comply. Thy base their calculator on a beam several meters in the air. Wonder the percentage of installations this actually covers...
@philyates40713 жыл бұрын
@@NToombes Especially as the Inverted L is based on one of the oldest antennas going, its half a Marconi T. There must be loads of amateurs using Inverted L type antennas. How about sloping end fed wires, we are not all lucky enough to have real estate that allows for masts and nice beam antennas. Come on RSGB pull you finger out.
@NToombes3 жыл бұрын
@@philyates4071 Exactly. plus ground mounted verticals. All of the antennas we mentioned here are very common and people are either just going to ignore the new rules or just lie if asked. Its going to become a rich mans hobby or they will sell off the frequencies. There is NO help abut for those that cannot comply.
@richardbracegirdle61043 жыл бұрын
I'm afraid (in my humble opinion) this spells the death of the hobby for many urban operators especially at 400 watts full UK legal power with a directional beam antenna.
@johnharrison57033 жыл бұрын
50w and I can't comply
@richardbracegirdle61043 жыл бұрын
Hi John - I think this is a knee-jerk reaction by OFFCOM - whilst it does and should apply to microwave commercial installations for public safety - it should not be applied to HF and our hobby. There is no scientific proof whatsoever that non-ionising radiation at the HF end of the spectrum - does any harm to human tissue. OFFCOM have over-reacted and should have never applied this to Amateur Radio. Like I say - there will be many urban amateurs who simply cannot comply unless they go QRP. I am surprised that the RSGB simply rolled over with this and did not fight it tooth and nail.
@johnrogers99503 жыл бұрын
@@richardbracegirdle6104 We fought very hard and got lots of changes from Ofcom. This is happening all over the world not just in the UK. FCC in the USA bring in similar rules (with different limits) from May 3rd and we are working together with Experts from ARRL and RSGB to help amateurs demonstrate compliance in both countries
@richardbracegirdle61043 жыл бұрын
Hello John, I hear you but - having worked with HF/VHF radio equipment mostly all my life - the case that should have been raised was that there is no known scientific (or otherwise) proof that non-ionising radiation at HF damages human tissue. Plus - whether you admit it or not - urban amateurs will really suffer with this and lots will be unable to comply. Especially as I have already mentioned - those with directional antennae. I'm sorry but I do not believe the RSGB has done enough to persuade OFFCOM that whilst this legislation is fully applicable to commercial microwave installations for human safety factors - the reasons used for it simply do not (and should not) apply to our hobby. It is a blanket approach by OFFCOM to the whole RF spectrum and wholly unnecessary in the case of Amateur Radio at HF.
@southyorkshireghosthunters3 жыл бұрын
@@johnrogers9950 Hi John i have spoke to many Americans on the radio and they have never heard of this happening in the United States or any other country
@brian.79662 жыл бұрын
It looks like I have to pack up using any radio at my QTH, ah well I had a good run,
@SteveG4YTK3 жыл бұрын
Thanks John for the explanation. I am pleased that I only use 50w on CW and FT8/FT4 to my DX COMMANDER CLASSIC Ground mounted vertical. I am taking this has a 1/4 wave verticals. This means I am compliant without taking any more action. If I increased my power 75w which I don't I would be in the boundary of our neighbours garden. Would be interested if you agree. Steve G4YTK. Ps I do have worries for the continuation of our great hobby.
@SavinoLeo3 жыл бұрын
Thanks John , very useful tool , is the antenna choices going to be updated pls , for example add Ultrabeam , End fed , slope , etc ? Thanks again. I have read all the comments and I do have worries for the continuation of our great hobby.
@johnrogers99503 жыл бұрын
Yes WIP
@johnharrison57033 жыл бұрын
Is this calculator anywhere near finalised yet. What about people with small plots and ground level fed antennas. The 3.4m then becomes a distance from the base as I see it. That includes my 2 neighbours property, so I am no longer able to operate legally.
@icsp23 жыл бұрын
Don't put anything in the form that should affect your operating, make it up, Ofcom won't do anything as they can't even take the idiots of the air.
@NToombes3 жыл бұрын
Sounds like your setup is identical to mine. Becoming convinced they are trying to make it harder for us to operate then they can start selling the bands off.
@johnrogers99503 жыл бұрын
As long as no-one is in their gardens when you transmit you cannot be exposing them to NIR
@johnharrison57033 жыл бұрын
@@johnrogers9950 thats not much help at weekend when there's a contest on and the kids both sides of me are out playing.
@TheTemporalAnomaly3 жыл бұрын
In these cases I suppose you could implement a system to electronically monitor the area around the antenna for the presence of people - Think PIR detector or something similar, then you could be alerted to stop transmitting when the neighbors are hanging out their washing or sunbathing etc. This way you would still comply as the RF field won`t be present when personnel are withing the exclusion zone. (It could even be automated) The RSGB site says you can do this when operating static mobile (by simple observation) but I would be interested in hearing comments from John Rogers on this idea. Chris. G7dom
@patrickmolloy69942 жыл бұрын
for some antenna, I have a GAP Titan DX or example, it's really difficult to use this form.
@stormrider82362 жыл бұрын
One of my biggest concerns with the 'calculator' is that is uses pre-prepared data about Rigs, Feeders & most dangerously antennas. In the wrong hands i.e. a planning dept at the local council offices, or some zealous wannabe in a government dept, it 'could' be used against us, as evidence, forcing licence holders to only use 'prescribed equipment and/or antennas'! Don't say it could never happen, because its already been tried here in the UK, when Citizens Band Radio was first legalised. All operators were only supposed to use a stipulated antenna (according to the licence back then), the guidance that came with it, on where it was supposed to be mounted was farcical and the resulting TVI etc caused howls of dissent. The legislation and advice was quietly dropped- but my point is, if they've done it before then some Muppet will try it again and WE don't need to be handing them the ammunition to do it. Once this 'genie' is out of the box, you will NEVER get it back in - RSGB you have a duty to all operators when it comes to this, not just current members. Lin M0TCF.
@billsomerville28323 жыл бұрын
I am confused by a fundamental issue. If EIRP power is being used, i.e. a point radiation source, why are these separation distances referenced to the nearest part of the aerial. At least for aerials with a primary radiating element less than or equal to a 1/2 wave extent, the feed point is the notional isotropic source of radiation, and distances should be referenced from that point? Clearly near field conditions mean that interactions with the whole aerial need to be considered, but outside of the reactive near field the assumptions of an isotropic source should be used consistently. Does the Ofcom calculator underlying this calculator specify that any part of the aerial, i.e. the nearest part, must be used for *all* separation distance measurements between aerial and the public?.
@johnrogers99503 жыл бұрын
The calculator is a conservative model and may give distances larger than necessary but are still compliant. If you cannot accommodate the calculated compliance distance using the algorithm built in from Ofcom you can use pre-assessed configurations we are preparing. First one for 40,80,160m dipoles is now on the RSGB EMF site
@johnharrison57033 жыл бұрын
@@johnrogers9950 just had a look at these. Great work. Sorry but why start with antenna situations that stand a chance of complying because they are in the air where height is helping separation. We are weeks away from this becoming part of the licence, would it not have been better the help understand cases that are marginal / non compliant. Many have no chance of dipole on 40,80, or top band. To get on these bands fir me and many in my area are long wires fed a ground level and run up to roof or wound around garden fence etc. Ther are several hams in my area who will all be in the same situation. So far RSGB communications seem to be looking at situations that work and suggesting there is no issue. Well done to all that are putting in the work needed to produce these calculators and papers, Its hard enough trying to work in my small space on HF without this added hurdle to get over.
@johnrogers99503 жыл бұрын
@@johnharrison5703 We are trying to get a clear agreement on how to demonstrate that fields are below reference levels for electro-stimulation (table 8) "unperturbed rms for peak spatial E (
@mervcox17263 жыл бұрын
Hi John, Just wondered are they going to update the antenna choices? as There is no Ultrabeam 8 Band Beam, 2 El. 6-40m
@johnrogers99503 жыл бұрын
Yes it is WIP
@paulkazjack3 жыл бұрын
As a newly licensed operator 2e0 i want a full refund from ofcom for all the money ive spent on my radio equipment. None of this shi t was mentioned while taking my money for the the 2 exams ive sat. Now they've dreamt up some rules which makes me 'non compliant' in there view. I now give up! Wheres my money ofcom/Rsgb??
@davex7223 жыл бұрын
John must despair at some of the comments posted here. OFCOM haven’t dreamed up rules, they are requiring compliance with international requirements that have been in existence for more than 20 years. At the intermediate level, meeting the requirements is much easier than a full licence looking to operating at 400 Watts. If you think it isn’t fair to have to meet the requirements, consider some of our fellow hams overseas who have to specify equipment make, model number, serial numbers, wait for approval and then employ professional antenna riggers... all we have to do is fill a few cells in a spreadsheet.
@graeme91843 жыл бұрын
Can someone tell me if ladder line comes under the regulations. In theory it does not radiate, The doublet it feeds complies but the open wire exits a wall that public could touch it . How does this fall within the EMC regulations ?
@johnrogers99503 жыл бұрын
Ladder line is a feeder type it is assumed not to radiate and the losses are included in the cable type table
@steveplatt13772 жыл бұрын
Your question doesn't relate to so-called EMFs, if they touch it and they die it doesn't matter because it wasn't the fields that killed them ;-)
@Director4483 жыл бұрын
Thanks John, an excellent informative video which will help a great many people. A couple of things "other losses", if like me you have cable joins with 259's ,connections to SWR bridge, ATU, Baluns, Antenna switches etc. Also units with associated insertion losses say at -0.2dB each would surely have to be collectively added into this box? Some antennas are not yet included into the selection so you obviously use the custom setting. Again if like me you use an inverted L antenna with four traps. Investigation reveals that each trap would have a loss of around -0.8dB. So am I right in saying the the collective losses of the antenna is -3.2dBi so that would need to be input into the box? I suppose that the directivity factor would not really be known but as a rule of thumb maybe -3dBi because of the horizontal section. The vertical section comes down to around 3ft and the horizontal about 30 ft, Reading Ofcom's documentation they indicate that if a public area is enclosed by undergrowth (therefore not making it publicly accessible) or if the area is fenced off or has a locked gate with warning signs, it is not defined as a public area. They suggest this also to stop anyone "getting burned" by touching the antenna. I am going to do this anyway to one side of the antenna 2.5m away but the other side has a 7ft high brick wall 1.5m away. obviously no public access from a H&S point of view and with some overhanging branches should keep them well away. If you have a colinear for 2m on your roof, what about neighbours next door who MIGHT be in their loft so their head height would be closer to the antenna then someone on the ground. The antenna has gain but there would be substantial losses through their roof tiles say between -10 to -20dBi would you put that into the directivity factor box. Thanks again for an excellent video. Reading some of the posts, you said that you hadn't seen a compliant ground fed antenna in a small garden, is there an email I can send one of my assessment sheets to you so you can see how mine looks , they are all compliant . 73 de Mike G3ZCC
@johnrogers99503 жыл бұрын
Other losses should cover all joins in the feeder but do not overestimate as it may invalidate your assessment. You can check losses by moving meter and measuring power levels. My recommendation is always no touch and for many configurations observing that rule of thumb will also give a compliant separation. Traps are part of the antenna so should not be included in feeder loss. They will have reduced antenna gain and are included there. Be careful of low inverted L's we are modelling them to derive guidance. Ensuring no-one is present when you transmit ensures compliance. I use blackberries to protect my boundary near my inverted V and a camera to monitor people who may be close by in the adjacent park.We need to get a good estimate for directional factor of white sticks but suspect it will show occupants in upper floors are safe at reasonable powers. The losses through building materials are not as high as think particularly close to antennas at HF. I don't think I said I had not seen a compliant vertical certainly two that I have are compliant but I don't feed them at full power. I think it was Noel who said that not me.
@Director4483 жыл бұрын
@@johnrogers9950 Thanks for that, what I have done is create a block diagram of the station using a small autocad program showing all the plugs, antenna switches, swr bridge, external atu, cable joins etc with everything colour coded so they should be able to see where I am going. My other losses are 5.2db 26 plugs and switches etc and I have researched that these can be 0.2dB per connection or insertion loss. I am going to put an exclusion zone together as well. Kind Regards Mike G3ZCC
@Image_722 жыл бұрын
What’s the difference between SSB and SSB Processed?
@rodneyunderwood42063 жыл бұрын
Excellent thank you.
@johnrogers99503 жыл бұрын
Thanks
@deano32583 жыл бұрын
Thank you for this walk through very helpful. I have a vertical SX80 HF antenna (silver rod type) would I select the vertical di pole for this antenna in the drop down menu ?
@johnrogers99503 жыл бұрын
Quarter wave vertical
@srs263 жыл бұрын
Very well explained and very informative, thanks John!! Simon M0SYS
@johnrogers99503 жыл бұрын
Thanks Simon
@blasterb36483 жыл бұрын
I measure the average of my processed SSB signal as 20% of peak (when I whistle). Any more sounds horrible. I will use 20% in my calculations. An 'inverted L' aerial which a lot use for HF isn't on the list. 'Long wire' is but how long is a long wire? Amateurs will have to talk for less than 3 minutes at a time to keep their 'transmit %' at 50%. We don't usually know what the 'directivity factor' is, it would make a lot of difference as we don't usually aim our signals at people's heads (unlike the mobile phone transmitters). My hf aerial is compliant at 6 watts average EIRP but still shows an exclusion zone as 3.4 metres - this is ridiculous. The Ofcom calculator won't work below 10 MHz, does this mean that they never intended to require calculations below 10 MHz?
@johnrogers99503 жыл бұрын
Verticals, loops inverted L and other antennas are planned. Two stages model to find the strongest field positions and then fill in the antenna gain table. I am looking for volunteers to help our team with this work.
@davex7223 жыл бұрын
Will the final version of the spreadsheet use ICNIRP 1998 limits, or the later 2020 limits? I appreciate OFCOM refer to 1998, but surely the more up to date data is the better reference.
@iainmeteorscan15553 жыл бұрын
@Dave x Hi Dave. I assume this is the ICNIRP 2020 spreadsheet, as in the video @ 0:25 ICNIRP 2020 is quoted.
@davex7223 жыл бұрын
Iain, if you check the right hand top corner of the current RSGB spreadsheet, it refers to 1998 limits.
@johnrogers99503 жыл бұрын
currently we believe it will be 2020 but there are some contradictions in the ICNIRP2020 document around peak limits and ankle currents which we are trying to clarify with HSE and PHE and Ofcom
@zaperfan3 жыл бұрын
They are killing the hobby off they fail to regulate and want you to measure your POWER LEVELS I'm Blind I run 9w no more!!!!
@neilfellingham28043 жыл бұрын
When the calculator say "COMPLIANT as less than 10w EIRP" does the Ofcom Compliance Distance of 3.4m still apply or is this 3.4m for non compliant setups.
@iainmeteorscan15553 жыл бұрын
@neil fellingham. Hi Neil. Under the ICNIRP Guidelines, any system emitting less than 10W EIRP (that’s 6.1W ERP) does not require self-certification and is therefore deemed “Compliant”. My guess is that this is merely a convenience so as not to affect handheld radios! By and large, this will also usually encompass QRP (5W ERP) stations (unless using a gain antenna resulting in more than 6.1W ERP) and in some cases even UK Foundation Class Hams, particularly where their ERP does not exceed 6.1W (10W EIRP).
@johnrogers99503 жыл бұрын
You can use whichever method you wish to assess compliance, below 10WEIRP or compliance distance or any combination for MultiBand antennas
@rodwilkinson33043 жыл бұрын
Has the RSGB requested from Ofcom a written statement or been provided with one on a) how they intend to police this licensing requirement and b) how many additional field officers will they be engaging to the cope with the extra workload ?
@johnrogers99503 жыл бұрын
Guidance on EMF Compliance and Enforcement (PDF, 598.6 KB) P31 says
@rodwilkinson33043 жыл бұрын
@@johnrogers9950 Sorry John, but just what does P31say?
Thanks John, useful information from the Regulator but doesn’t answer my question to the RSGB.
@johnrogers99503 жыл бұрын
@@rodwilkinson3304 see page 5 of our response to Ofcom consultation EMF-Consultation: RSGB Response
@g0fvt3 жыл бұрын
Not good news for the hobby, field strength in my neighbour’s loft could be high on the rare occasion I used high power VHF SSB. I did use the previous calculator, I guess I need to do it all over again for every band.....
@johnrogers99503 жыл бұрын
I would wait to do them all again as further changes to calculator are likely. The current front sheet will stay much the same but hopefully more guidance can be added to other sheets on pre-assessed configuration limits to make the distances less conservative(ie smaller)
@g0fvt3 жыл бұрын
@@johnrogers9950 it does not take terribly long to run the calculator for each band, but I do have some concerns, one of them is the time over which the figures are integrated. Also field strengths for example in a neighbour’s loft.
@g0fvt3 жыл бұрын
@@johnrogers9950 Ok, having revisited the calculations and particularly the polar diagrams that can be legitimately factored in it is not as grim as my knee-jerk reaction would indicate.... obviously every case is different but in my small garden a wire dipole at 10m elevation does not appear to be a problem at 400w SSB. Thank you all for your considerable efforts with this.
@icsp23 жыл бұрын
I cannot load this silly MS spreadsheet on my computer, i don't have MS office. ! I won't / cant comply.
@icsp23 жыл бұрын
MS want £79 to use this spreadsheet, that won't be happening.
@davex7223 жыл бұрын
It works in Libre Office, on an iPad with iOS and in Google. No need to buy MS anything
@icsp23 жыл бұрын
@@davex722 how do I get it to load in Google everytime I click on the file I get ms trying to sell me office.
@MopH3ad3 жыл бұрын
www.freeoffice.com/en/
@timg5tm9413 жыл бұрын
Buy an old ft817 and put a towel over your 7300 if you need to. Simples.
@philyates40713 жыл бұрын
The linear is just to heat the shack...
@g4obb3 жыл бұрын
Too right....read my earlier comments....I shall see if i can see Uranus tonight...
@michaelrichardson48843 жыл бұрын
Can anyone simply tell me what SSB processed is does it refer to processed audio as if there was audio gain there would likely be higher average output sorry if it's an bit dumb but 23 years out of the subject I'm not sure what the processing means
@iainmeteorscan15553 жыл бұрын
@Michael Richardson Hi Michael - same here! I am assuming "SSB Processed" to mean the type of signal we Hams typically transmit on 20m (14MHz), 40m (7MHz) etc. I am, as you, at a bit of a loss as to what "SSB" refers to! Anyone out there help, please?!
@michaelrichardson48843 жыл бұрын
@@iainmeteorscan1555 I hope someone comes back and simply tells us the difference between the two. I'm sure the answer will be simple of course. I put it into google and from that no revelation as to my stupidity so I gave in but clearly people do know the answer out there.
@johnrogers99503 жыл бұрын
Single Side Band processed refers to using compressor in your radio which amplifies the low level signals which raises the average power and intelligability
@MopH3ad3 жыл бұрын
cant find this calculator anywhere
@johnrogers99503 жыл бұрын
link from www.rsgb.org/emf
@simonpritchard4723 жыл бұрын
Argh! What about handhelds, do these regulations cover them? (I expect all such operation would fail if so, so probably not -- and as has been said what about mobile phones?) How much SSB compression are we talking about and how do we measure it? What about reductions in field strength due to building materials (eg in the house below from an antenna mounted on a chimney)? This kind of tool being applied to a hobby like amateur radio is utterly inappropriate as it can never compensate for all the variety of circumtances we operate in and so cannot generally yield even vaguely accurate results. The only way we can comply in reality, rather than just meaningless box-ticking, is to actually measure and document field strengths -- and that might be kinda difficult to arrange in a neighbour's garden ot loft space! To say nothing of having to re-do every time changes are made in the course of our 'experimentation'.
@johnrogers99503 жыл бұрын
If you can ensure the power is such that average EIRP is less than 10W EIRP you are compliant. Remember most handle antennas have almost no gain and small ones have negative gain. We hope to build a database of manufacturers guidance to cover these by tabling safe distances for different power levels
@simonpritchard4723 жыл бұрын
@@johnrogers9950 Thanks John, noted. Though, if the whole point is to avoid excessive RF exposure, I would still imagine that the field strength from a TX held next to the head, even with a lowish power and inefficient antenna, is likely to be much greater than that from a much greater EIRP many metres away.
@grandpaandlucas70543 жыл бұрын
i had no email from ofcom about this new rule. what program opens the calculator. Another rsgb / ofcom balls up. what about the interference armatures get.
@johnrogers99503 жыл бұрын
I recommend you update your details before your licence times out
@grandpaandlucas70543 жыл бұрын
@@johnrogers9950 i have still no info
@johnrogers99503 жыл бұрын
@@grandpaandlucas7054 Any spreadsheet that will open an xls file excel or libreoffice
@johnrogers99503 жыл бұрын
@@grandpaandlucas7054 To validate your licence, you will need to log in to the Online Licensing System. An on screen prompt will appear asking you to check and update or confirm your details, to do this use the Verify my details button.
@grandpaandlucas70543 жыл бұрын
@@johnrogers9950 I logged on to ofcom my licences are listed. and it tells me this You last updated or verified your personal details on: 21/04/2021 18:47.
@icsp23 жыл бұрын
They don't police the bands so how are they going to enforce this nonsense. most big commercial radio stations won't pass this with pumping out Kw's but then they are making big money so ofcom will turn a blind eye.
@davex7223 жыл бұрын
Medium and long wave broadcast stations meet the requirements, check the graphs and you will see the allowable V/M levels rise significantly as you go lower in frequency. Equally, VHF and TV broadcast antennas are mounted on tall towers well above any members of the public. This web page calculator will give field strength for the “tens of KW” MW broadcast stations, see how close you can be and still be compliant. www.daycounter.com/Calculators/Maximum-Field-Strength-Calculator.phtml
@icsp23 жыл бұрын
@@davex722 What about the interference they generate on the hf bands while running 200kW will Ofcom come and tell the one near me to reduce power to give me the HF bands back. No they won't. Money talks.
@g4obb3 жыл бұрын
Ofcomm couldn't organize a shag in a brothel....nor could the RSGB
@zaperfan3 жыл бұрын
what a load of bollox
@wrote83 жыл бұрын
WRONG WRONG WRONG! You can't play around with modes, figures etc to get yourself compliant - you must take the maximum power of the most powerful transmitter on the site and use 100% duty cycle e.g FT8 and work out your compliance distance from that for all antennas that are in use on the site ( and re-calculate if any antennas are changed or added) . OFCOM are not going to accept all this rubbish about judging how long you are going to be talking on SSB or FM or whatever - they are not going to trust unsupervised operators to adjust their output power and mode so that they are always compliant (even if you make up a huge chart showing all the various levels to achieve compliance) I'm really disappointed that the RSGB have come up with this - you cannot try to wriggle under the fence it's an international initiative and we, as 'mere amateurs' will get hammered if we don't approach this problem in a highly professional manner - which this is not - I suggest you take this video down until you can re-script it. Additionally, for those contemplating using test equipment currently on sale, the equipment will have to have been recently calibrated and a calibration cert will have to be appended to the compliance - calibration of anything comes expensive.
@johnharrison57033 жыл бұрын
Read the Ofcom paper. They do allow average powers etc and the mode factors. Lot to read on the RSGB web site.
@davex7223 жыл бұрын
Above 10 MHz average power over several minutes is used internationally, so SSB for rag chewing on a 3 mins TX, 3 mins RX (or less in a net), will result in quite low average power. Below 10 MHz the allowable levels increase as the frequency is reduced, check the graphs. In my opinion, the likely worst case is someone running high power FM to a low elevation beam on VHF/UHF, with a close by neighbour where the beam can fire directly at their upper floor rooms... a situation that few of us need worry about. Regarding test equipment, unless you want to pay for a calibrated instrument in the Narda class, around €20,000 plus, or £1000 for a few days hire, forget it. The toys from Amazon and eBay are a joke.
@wrote83 жыл бұрын
@@davex722 If your neighbour decides that your radio gear is the cause of his brain tumour then if your station is compliant at the worst case (max power on worst freq) then there is no case to answer. However if you have an RSGB 'bitsa' compliance assessment then your neighbour's lawyer is going to take you to court and mercilessly cast aspersions on your honesty in applying that assessment at all times and you will not be able to prove otherwise. It's scary stuff in my view! I'm becoming very p'd off with government interference in my hobbies - my other hobby, model flying, has been blighted by government regulation mainly because someone at Gatwick thought a black bag blowing in the wind was a drone and shut down the airport, costing millions! Grrrr
@4X4-RADIO3 жыл бұрын
Duty cycle is measured over "Periods" of time, 1 min, 5min etc... FT8 is not 100% duty cycle... It transmits for 12.6 secs in a 15 sec period, repeated twice in a 1 minute cycle. So in a 1 min period TX is 25.2 secs & RX is 34.8 secs
@iainmeteorscan15553 жыл бұрын
@@4X4-RADIO Hi Dave. Based on your figures, a single FT8 contact is 84% duty cycle, and continuous FT8 is 72%?