Aerial

[Murphyv310]

Hi.
Well my house is high up. The shed is 9 meters to the nearest point of my house. I have one neighbour to one side that is joined onto my home. There is no houses behind the shed and no access to that area for 20 meters at the nearest point. Our part is built up to one side by 4 meters no antennas are overlapping my neighbours property and so far I'm only on 2 meters, I have a slim jim on a 5 metre pole (approximately) and a yagi on a separate 4 meter pole that points totally away from houses to access the NI repeater. Both calculators tell me that the radiation is under 2 meters for the slim jim and under 3 meters for the yagi on the direction of maximum signal. I calculated cable loss and a maximum of 10 Watts PEP output which is my maximum as a foundation license holder. If I calculate for the intermediate with 50 Watts PEP I just scrape by, 55 Watts I fail on the yagi, but the issue is the calculators really do not properly take into account antenna height due to the contours of my area.
So I'm fine as a foundation license holder and will be when I increase power under the intermediate. Full licence holders are the ones that could be badly hit. I'm more into QRP operating and when I eventually do get an antenna up for HF that will be my preferred mode of operation.

[Murphyv310]

Hi.
Here is a print out from the Ofcom calculator for 145.500 Mhz and a 5 element yagi.

[Pye Man]

I would say in my situation, after 45 years holding a licence, my days of using full legal on HF (albeit the only way I am able do this is on CW) and 180w PEP or thereabouts on SSB are over. I live in an urban area and have a small garden that will accommodate a reasonable piece of wire that is not too obtrusive but neighbours either side.

On 2m SSB, on which I was once very active, other than 10w PEP in my very early days I never ran more than 3w. However, part of the fun, and my interest, was building aerials, the largest of which was a 20 element, to get the ERP up and make the most of a little. I worked some remarkable Dx under tropo. (I also did the same on 70cm but was less active on there.) I would probably need a very high mast to do that now and I don’t think I’d want that much metal way up in the air. Just above roof line and turning it into the wind when there was a gale on allowed me to sleep easy in my bed.

Now it depends on my enthusiasm which, rekindled a little with time available under lockdown, has now taken a dent. I was active as an SWL and then licenced through what are for me glory days of ham radio in the 60s/70s/80s when the HF bands were alive with stations – even 10m with the sunspot cycle in the late 70s/early 80s. 2m was busy, there was activity on 70cm and lots of interesting stuff to find on short wave. These days, the bands are a shadow of their selves and the noise level is often S9. Trying a receiver recently I had to use the signal from a GDO to check if the thing was working on 20 and 15m.

With this latest edict is it worth the effort? Amateur radio is dying. It has been in slow and steady decline for years. Talking to someone the other side of the world is no longer the exotic experience it once was - you can do that on Zoom. The frequent navel gazing regarding membership and the future that the RSGB indulges in, the steady disappearance of the once many radio/electronics hobby magazines and the local clubs that are either moribund or closed tells you plenty.

Perhaps its only going through the same process as other pastimes, familiar in youth to those of us of a certain age, that have also their day. Perhaps I should concentrate on and enjoy my classic car before that is legislated off the road. Perhaps it’s another case of thanks for the memory.

[Murphyv310]

Hi.
Sorry to hear you feel so downhearted about amateur radio these days.
In fact lockdown has massively boosted numbers taking the foundation and intermediate exams. For me I wanted to do this for many years, bringing up three children, working many days from 8am to sometimes 10pm repairing cars and doing virtually constant DIY around the home put paid to amateur radio. Now I'm retired, the kids are gone and lock down I did it.
Don't give up, with 10 Watts you'll get plenty of QSO's put up a magnetic loop for RX and have it switched for RX and your dipole for TX with a relay to short out the loop on TX too.
Don't worry about EMF you'll be fine.

[roadster]

There has been a lot of discussion about this on the GQRP club and VMARS reflectors.
In the Ofcom document:  https://www.ofcom.org.uk/__data/assets/p...ersion.pdf
It clearly states, on page 3: Equipment transmitting below 10 W EIRP automatically complies.
I am not going to do any worrying until the final version is published. I am in the fortunate position of being in a rural location with no immediate neighbours but did a basic check  using this calculator:  https://www.vk5dj.com/VK3UM%20EMRCalc%20...nstall.zip. I am unable to use the Ofcom calculator as it uses Excel, which  now requires a subscription. Without putting in any aerial gain or feeder losses my max 300W on HF on my long wire which has a minimum height above ground of about 6m it is acceptable to stand directly below on any HF band, unless you are more than 3m tall.
I think that the problems with compliance will be with high power mobile setups and demonstration stations at fetes and other public events, again if aerials are mounted on tall towers, there should not be a problem.
Rod

[AdrianPH]

I do satellite work through QO-100 DATV, the rms output is on 33 watts but by the time you add the dish gain the EIRP is something like 16,600 Watts, trying to work it all out I got a save distance to be something like 6.3 metres from the dish when it points at an elevation of 23.5 degrees for the SAT, so not as bad as i thought it could be, the dish sat on the ground at a centre height of 1.5 metres. There are clubs and societies working things out for all the different activities.

I have two other antennas, a 20m wire dipole at 4.6 metres high and a 2m/80cm antenna in the loft, but as I only run 1 watt to that I will ignore it for now.

Do not give up the hobby, when things get finalised then start to work things out. You may be surprised at how little distance is needed.

Adrian

[peter scott]

It's a nice day here today so I decided to walk up to the trig point on our local volcanic tributary. You get a good view up there and it's always nice and warm even when the sun is not shining. I assume the warmth is volcanic.

Here's the view looking north east towards the local volcano.

   

And from the same spot the view looking south east.

   

or the same view in wide angle.

   

Peter

[ppppenguin]

Volcanic? I know Edinburgh is built on radioactive granite but with that dish pointing at you it's more likely microwaves.

[peter scott]

Yes, the volcano is long since extinct but the dish isn't. Perhaps it's just a receiver?

Peter

[ppppenguin]

I do satellite work through QO-100 DATV, the rms output is on 33 watts......

I presume you mean average output. RMS power (unlike RMS voltage or currrent) isn't a very useful concept. RMS voltage * RMS current = Average (or mean) power. This assumes that current and voltage are in phase.