Some interesting discussion on various Facebook groups recently about the more serious side of PMR446.
As we all know, PMR446 is intended as a low powered, short range, licence free service. However right from the very early days of PMR446 it became clear that users who were willing to put in a little effort would be able to make some remarkable contacts.
Simply walking up to the top of a local hill or other high point results in a massive increasing in range. The 500mw output power and fixed antenna which are part of the legal specification were implemented to keep range down to a matter of hundreds of yards when used in homes, offices and workspaces but from a good location the same radios are able to reach stations many miles away.
Thus, the idea of DX-ing on PMR446 was born with long distance contacts being made on a regular basis.
In the early days PMR446 radios weren't cheap, I paid £100 for a pair of Goodmans Trackers in the late 90's, so methods such as 'Inductive Coupling' were used to connect the radios to an external antenna - A coil was soldered to some coax and slipped over the existing antenna.
As time progressed the prices fell and people experimented by removing the fixed antennas and replacing them with longer, more efficient antennas or soldering BNC connectors in place of the standard antenna.
A great deal of fun was to be had experimenting with PMR446 radios in this way. Of course as soon as you modified your radio, it became illegal to use but that wasn't likely to bother those indulging in such pursuits!
Now, fast forward 20 years and standard PMR446 radios are cheap as chips but so are more 'professional' radios such as the wide variety of Baofeng radios on the market. Boasting higher power and removable antennas, Baofengs have become the radio of choice for many PMR446 users.
Some, not happy with walkie talkie type radios, started to use larger Amateur Radio equipment made by Yaesu, Kenwood, Icom, Alinco etc. Many of these radios are easily modified to operate on the PMR446 band and offer much higher power. This is great for the 'serious' user who wants their signal to get as far as possible... However, there is a major potential problem with such activities......
Let's say that Mrs Smith has bought some standard PMR446 radios so she can keep in touch with her children while they play in the garden at home. She knows nothing about DX-ing or high powered radios, she believes that the radios will transmit to the bottom of her garden or maybe to the end of her street but that's all. One day she is checking up on her children and suddenly another station comes onto the channel and completely wipes out the channel. She is unable to contact her children. She shouts at the other station, asking them to move to another channel. Unfortunately, she gets no reply despite numerous attempts. You see, Mrs Smith has no way of knowing that the station in question is in fact 50 miles away and is using 25 watts of power into a home base antenna on their roof. You can imagine that Mrs Smith would be annoyed and angry that the station is ignoring her requests to move channel. Again she has no way of knowing that the strong station cannot hear her transmissions (Her radio only has 500mw output after all).
This is something that higher powered stations, 'Pirates' I guess we could call them, should consider very carefully!
Now, lets be honest, this type of activity is illegal. If you are caught you could face prosecution or even imprisonment. However the reality is that, much like CB Radio, there are always going to be plenty of people willing to take what they feel is a a very small risk of getting caught.
So assuming that this situation is unlikely to change anytime soon maybe such users could consider a more responsible attitude to operating on the PMR446 band?
How about everyone keeping their power down to an absolute minimum? - ONLY USE WHAT YOU NEED - If you are talking to your mate in the next village, do you really need 50 watts when 1 watt will do?
If you hear other stations on the channel, how about changing to a different one?
Make sure your radio is set to NARROW FM, a wide FM setting will result in you splattering across several channels.
Talking about channels, since 2018 the PMR446 allocation has been increased from 8 to 16 channels. Most standard PMR446 radios are still only available with the original 8 channels so you could avoid causing interference by simply using channels 9 - 16 instead - As an experiment, have a listen on these channels for a few days and you'll probably find them to be very quiet or totally dead in most areas.
Calling channel - Channel 8 is widely known as the calling channel on PMR446. This channel was originally chosen as it was the highest channel and least likely to be occupied (Most radios are set to channel 1 when first powered up, it was soon found that many people tend to use channel 1 or one of the lower channels as a result - They simply never got any further up the band). This has worked well for many years but the increased use of higher powered radios and external antennas has seen a corresponding increase in interference to and from other users. Maybe it's time for a new 'DX Calling Channel' on the newer part of the band (Channels 9-16)....?
ONE-FOUR a copy????
So in conclusion, if you really must operate non-standard equipment on PMR446 can I suggest that you keep other users in mind, keep your power down to a minimum and seriously consider using channels 9-16...
One other thing, don't be fooled into thinking that using a frequency in between the normal channels such as 446.100 or 446.150 is a good idea.... These frequencies are often used by licensed operators such as local businesses which are unlikely to take kindly to their communications being disrupted. Indeed, the very reason that PMR446 has an unusual frequency offset is to avoid such problems occurring!
So, have fun but please be a responsible user!
