finestgreen
Well-Known Member
The risk is harmonics and spurious emissions transmitting on a channel you didn't intend.
How to get a Private VHF Frequency
- Thread starter picardy
- Start date
Neeves
Well-Known Member
The thread has been quite interesting as it has defined what is legal or not and where expertise and licensing is needed.
Everyone else manages 'similar' businesses, some quite large, using public channels or mobile phones.
What is so special that demands a private channel where a mobile phone would not suffice?
Jonathan
Neeves
Well-Known Member
The OP implies they use fixed VHF - what is wrong with using them on Ch16 in an emergency - that's what its for. The OP seems to want exclusive use of a channel, on fixed VHF on vessels, in order to manage the family business.
Jonathan
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ylop
Well-Known Member
How do you know they don’t have private channels? By their nature they would not be traffic you hear!
I think you might be reading too much into “private”. The OP is clearly not a VHF expert (or he would not be asking here for advice that ofcom provide for free). So I suspect he is either using the phrase “private channel” colloquially to mean “channel that isn’t interfering with the neighbouring traffic” or he’s been told by a customer/competitor/pub-know-it-all that he can’t use his ship radio license on shore and needs a private channel.
In terms of mobile phones use - whilst I think they can do a job, they are not always ideal. Reception black spots; ability to simply transmit to a group; robustness. He might also have a “legal headache” if any of the staff are using the “radio” whilst driving - rightly or wrongly vhfs are outside the handheld mobile phon whilst driving rules, whereas clearly phones are not. Now there will be arguments about whether the boatyard none of us have seen is a road or other public place but that doesn’t mean his insurers will care. Bluetooth isn’t a great solution if people are jumping in different vehicles regularly.
I don’t think he said exclusive.
Refueler
Well-Known Member
mmmm sorry to dissapoint you - but it falls under the category of "Driving without Due Care and Attention" or other .... as some who have been prosecuted for various have found out ..... even eating a choc bar !!
Alicatt
Well-Known Member
Here you can't eat, use a mobile phone or microphone, but you are allowed to drink while you drive ... some seem to think that also includes alcohol
oldgit
Well-Known Member
Ofcom maintain a team who deal with complaints about interference from unauthorised use of the radio spectrum.
We frequently used to have complaints from companies suffering from other folks transmitting on the" their" frequency.
In some cases it would be a Taxi company having problems with another Taxi company on the same frquency and tonelock
For a human with local knowledge it would be obvious that the line of sight distance between Sheerness and Southend is only around 10 miles the computor considered them to be in two different counties so must be miles away from each other.
When anybody finally got fed up and contacted Ofcom, they would request you kept a log with times and dates and note the conversations ie general social natter or work related.
If you were really really persistant, Ofcom would monitor the frequency and if they could identify the offenders do something about it, including making an example of somebody.
"We may carry out an investigation in response to a complaint or report of non-compliance. We also use an intelligence-led approach to proactively carry out inspections to ensure use of radio equipment is complying with the law.
For example, we may inspect:
recently licensed radio equipment;
suspected unlicensed use of radio equipment where a licence has been revoked or surrendered; or
general compliance with all the terms and conditions of a licence.
Our teams of field officers have rights to enter premises, and test and inspect installations and equipment. These inspections can be unannounced.
If the evidence gathered during our investigation indicates that a person’s use of radio equipment does not comply with the law then we may consider it necessary to take enforcement action."
A gentle warning and confiscation of the equipment was the normal action.
From memory the do have the right to enter premises and confiscate ?
You then did have the right to go to court and claim the confiscated items back if you could prove they were type approved. and being legally used.
We frequently used to have complaints from companies suffering from other folks transmitting on the" their" frequency.
In some cases it would be a Taxi company having problems with another Taxi company on the same frquency and tonelock
For a human with local knowledge it would be obvious that the line of sight distance between Sheerness and Southend is only around 10 miles the computor considered them to be in two different counties so must be miles away from each other.
When anybody finally got fed up and contacted Ofcom, they would request you kept a log with times and dates and note the conversations ie general social natter or work related.
If you were really really persistant, Ofcom would monitor the frequency and if they could identify the offenders do something about it, including making an example of somebody.
"We may carry out an investigation in response to a complaint or report of non-compliance. We also use an intelligence-led approach to proactively carry out inspections to ensure use of radio equipment is complying with the law.
For example, we may inspect:
recently licensed radio equipment;
suspected unlicensed use of radio equipment where a licence has been revoked or surrendered; or
general compliance with all the terms and conditions of a licence.
Our teams of field officers have rights to enter premises, and test and inspect installations and equipment. These inspections can be unannounced.
If the evidence gathered during our investigation indicates that a person’s use of radio equipment does not comply with the law then we may consider it necessary to take enforcement action."
A gentle warning and confiscation of the equipment was the normal action.
From memory the do have the right to enter premises and confiscate ?
You then did have the right to go to court and claim the confiscated items back if you could prove they were type approved. and being legally used.
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Mark-1
Well-Known Member
Ahhh, I hadn't considered that, thanks. Rules it out for the OP who sounds like a heavy user who needs to keep his nose clean. However for the rest of us:
I know nothing about RF but my gut feel is that should be pretty easy to test for in my back garden and most likely affects adjacent channels. I also get the feeling the guys who buy these radios typically have some reasonable knowledge and would say in the reviews if they were that bad.
Hopefully, modern DSP/Filtering/Frequency Synthesis mean that a current cheap Chinese radio has more precise control over the transmitted signal than a 'quality' radio a few years back.
Having said that quality branded kit that should have passed EMC testing is sometimes very definitely non compliant, so who knows.
Most of all, it's really cheap.
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ylop
Well-Known Member
That requires the prosecutor to show that your driving was affected by the action. The exemption for radio use exists because taxi's, cops etc use radios whilst driving all the time. It is not possible to draw an inference that use of a radio whilst driving is automatically Careless Driving (s3 of the RTA - which is commonly described a "Driving without due care and attention"), this is why the construction and use rules on mobile phones were created, because the evidential burden that using a phone was inherently careless driving was too high.
There are all sorts of claims like eating a chocolate bar are DwDCA - I don't believe anyone has ever taken that to the appeal court to actually test it.
oldgit
Well-Known Member
Many years ago a chum had some radios knocked up in China, these were sold under a very well known brand and in a once very well known outlet which has since gone bust.Ahhh, I hadn't considered that, thanks.
I know nothing about RF but my gut feel is that should be pretty easy to test for in my back garden and most likely affects adjacent channels. I also get the feeling the guys who buy these radios typically have some reasonable knowledge and would say in the reviews if they were that bad.
Hopefully, modern DSP/Filtering/Frequency Synthesis mean that a current cheap Chinese radio has more precise control over the transmitted signal than a 'quality' radio a few years back.
Having said that quality branded kit that should have passed EMC testing is sometimes very definitely non compliant, so who knows.
Most of all, it's really cheap.
They were cheap and designed to under cut the decent stuff from the competition.
A radio was sent off for UK type approval....and failed.
Problem.
Large quantities were already on their way in a shipping container with a few even flown in for demo and sales .
The importer had a bottom clenching few months while they went on sale , but got away with it and was handsomely rewarded for his efforts.
The design was modified and resubmitted for type approval...and passed.
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Dellquay13
Well-Known Member
I’m not an expert in rf propagation, but as I understand it, (from knowledge of musical instruments and valve amplification where harmonics are positively encouraged) harmonics are typically at multiples of the original frequency, eg 2.2khz, 4.4khz, 8.8khz, not at any adjacent frequencies like 2.3 or 2.4khz.Ahhh, I hadn't considered that, thanks. Rules it out for the OP who sounds like a heavy user who needs to keep his nose clean. However for the rest of us:
I know nothing about RF but my gut feel is that should be pretty easy to test for in my back garden and most likely affects adjacent channels. I also get the feeling the guys who buy these radios typically have some reasonable knowledge and would say in the reviews if they were that bad.
Hopefully, modern DSP/Filtering/Frequency Synthesis mean that a current cheap Chinese radio has more precise control over the transmitted signal than a 'quality' radio a few years back.
Having said that quality branded kit that should have passed EMC testing is sometimes very definitely non compliant, so who knows.
Most of all, it's really cheap.
Checking a cheap set for interference at neighbouring channels might show how accurate and tight it’s initial tuning is, but any harmonics are likely to be way out of the marine band interfering in who knows what transmissions.
(I just chose those frequencies for an easy maths example, and know they are not real marine vhf frequencies, before everybody piles on calling me an idiot!)
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st599
Well-Known Member
Nope, a harmonic is an integer multiple frequency. You can't test it in the garden.
First Harmonic is in the middle of Defence Radiolocation.
Refueler
Well-Known Member
All apparatus that is hands free and can be used without physical action are allowed ... so your selective post is actually not quite correct. Taxi's etc that I have been in over the last years since mobile phones etc. came in ... and sad to say - the odd police car I've had 'interaction' with all use hands free comms ... whether its RF or Mobile.
Reason Mobiles were targetted was because of the number of people who did not use hands free ... If CB radios had been more seen - it would have been CB's ...
There are various news reports of people fined for various actions in a car ... incl choc bar eating .... even bizarre such as woman touching up make-up ... rare - I agree - but there.
Refueler
Well-Known Member
But there are also 'bleeds' of a trsnamission that can be not at multiple of the freq. This is common with boosted or overpowered RF units.
It used to be a problem with boosted CB radios .... 27 and 35MHz Model radios when people boosted to do long distance stuff ... thev channel selected would be OK - but channels either side were often interefered ..
st599
Well-Known Member
Looking at some tests undertaken by amateur radio operators, the Baofeng fails compliance tests in the 2m (144-146) and 70cm (440) bands. These are close to the marine band and PMR band, so probably not compliant in those either.
Yes, you get bleed caused by pushing the power amplifier in to the non-linear domain and you get harmonics of the intermediate frequency and the mixer frequencies. Most of which can be stopped by good (but more expensive) design.
noelex
Well-Known Member
My post was referring to Baofeng (and similar) radios. These have not been type approved to transmit on marine VHF frequencies, even though they will do this.
I sometimes use these radios on ham frequencies to communicate with my wife if one of us is ashore. We both have ham licences and are sometimes cruising areas outside mobile phone coverage.
When collecting one of us ashore we therefore sometimes carry these radios in the tender. In an emergency situation with no other means of communication I would use the radios to raise an alarm on marine VHF frequencies (although I have never done this). While not type approved, I believe use in this situation would not be illegal.
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Daverw
Well-Known Member
My understanding is that simplex communication affects the concentration less than duplex as per phone use, you are correct that the offence can be driving with lack of due care and attention
ylop
Well-Known Member
That is not quite right. A TV could be handsfree but its on offence to play video where it can be seen by the driver whilst driving. Similarly just because you use a hands free phone doesn't mean that you can't be prosecuted for careless driving if your interaction with the device affects your driving. To be more pedantic (or accurate as I like to call it!) the distinction is not handsfree - its handheld. You can tap the screen of a device with a finger and not commit the s41D offence, and you could
There are still taxis around using radios although far fewer than previously. Ambulances, police etc all still regularly use radios with fist mike. Traffic cars may be more sensible? Not unusual to see "ordinary" cops using handhelds - usually on their lapel round here.
I think its more to do with the number of people hitting things when on their phone!
Oh I've seen reports in the media, that doesn't make it the law:
- Cops make mistakes interpreting the law
- Drivers say they were driving normally when they were distracted
- Drivers pay fixed penalties to avoid going to court even when convinced they were right
- Some prosecutors will realise its a ropey case and drop it, some will not have that delegated authority
- Some magistrates may agree with cops interpretation of the law in the absence of specific case law
So to actually establish that "eating a chocolate bar" is driving without due care, needs:
- Cop to think it was an offence, and issue a penalty not just a warning
- Driver to believe it was not an offence
- and have deep enough pockets to fight it
- the prosecutor needs to think its worth fighting
- the magistrates to agree with the cop and then the driver appeal the case OR
- the magistrates need to disagree with the cop and the prosecutor appeal the case
- AND the appeal court needs to hear the case and decide that eating a chocolate bar is driving below the standard of a careful and competent driver; which even then may be specific to the fact of the case - at 70 mph whilst overtaking on the motorway would not be the same as whilst sitting waiting at traffic lights!
Then it will be an offence, until then its just rumour!
Refueler
Well-Known Member
[/QUOTE]
Who mentioned TV's ???
I assumed that people would understand that the phone is in a holder and linked to Hands Free ... ie like my Range Rover ... soon as I get in car - phone auto connects and any call in / out is done via the cars system.
[/QUOTE]
Taxis with radios are few and far between now - given the mobiles ... and that many taxis are now using WAZE or Googlemaps ... along with Hands Free.
Ambulances etc. - usually the second person up front is on the radio IF its a fist mike ... not the driver...
[/QUOTE]
My comment was general and would include that ...
I am not going to waste time trying to go back over years of BBC / other online news to prove it ... but it is a fact that drivers have been prosecuted - OK - lets widen that to also given Penalty's - for choc bar eating ... tidying up make-up ... reading newspaper .... all sorts of distracting actions ... not just rumour.
colind3782
Well-Known Member
Without wishing to quote the last two posts in full, current ambulances have a fist mike but also have a "hands free" type system for the driver.
