Anyone interested in running a coordinated radio communications range testing trial some time?
This would be of use to see what, if any distance coverage can be achieved from our various locations using our existing equipment.
Until we have sufficient numbers of Licensed Amateur stations, this will have to be conducted entirely on license free PMR446 and UK CBFM bands.
Lighspeed,
Good plan. Although I don't have any equipment yet. I have an old AM/FM/SSB Multimode CB radio with a few mods. I should really get one sooner rather than later.
Suggest you don't use that equipment to transmit anytime soon as its illegal!!!
The PMR446 equipment is relatively inexpensive now. For example I just hit on e-bay and for just over GBP 10.00 with 8 minutes to go:
http://www.ebay.co.uk/itm/2-x-Cobra-Micr...4ab2b2a12e
:-)
I'll have a look out for one.
Testing at the moment won't tell you much due to the unpredictability of background interference, but... I always say "stay simple, and don't rely on up to date equipment" if it goes wrong it's very difficult to find replacements compared with the ease of repairing or replacing a UK27 or an old Cobra, or superstar SSB set.
When the time comes, the radio "noise" caused by industry, 10 year olds on their CBs and general rf transmissions that restrict clear communication between low powered transceivers will have dropped to a level that will reliably allow simple 4 watt UK27 sets to be used locally (within 25 miles or so) while SSB will easily and clearly cover the UK mainland using no more than 20 watts (I've connected with Orkney from central London on mobile equipment quite recently). The only mode I wouldn't recommend if you want to remain relatively private is straight AM frequencies as two guys with wire coathangers can find your location very quickly if they want to.
I have a 27ft omnidirectional antenna mounted out back, just in case....
just got my self some magicbox long range pebble twin two way radios are they any good i no its off topic but would like to have your expertise thanks
They should do what theyre supposed to... But Remember... Using short range comms will alert any prospective aggressor to your general proximity should they scan a signal (even if it's digital and can't be deciphered) secondly; they will also know that your base is fairly close, because youre using short range gear... And thirdly; if you are away from base and foraging, or exploring with others, you should remain in clear view of each other at all times and use hand signals where possible so as not to alert strangers, or prospective prey animals.
All agreed. Although we hope most people won't have the equipment nor the skill to do so.
Hi Barneyboy,
I do not know the exact radios you have purchased, but if they are PMR446 they will work as advertised.
Rechargable AA or AAA battery powered units are preferrable over units using bespoke battery packs as thos packs are both expensive and also less readily available.
Hi Preacher,
Absolutely true that any agressor hearing a low power PMR signal will know that you are nearby. That's exactly the reason for considering how to remote operate a PMR transmiter.
On the other hand, low power = short range and is not hearable from long range. Even at long range and with SSB, signals from high power stations can be triangulated. High power lets more people know of your presence which can be a good and a bad thing.
Its good that you can make contact with Orkney, sounds like your station is well set up. Are you able to get contacts all the way between you and Orkney? Received wisdom says that it would not be possible at CB frequencies, but there is always somthing new cropping up in radio.
If you've been able to do this at CB frequencies it would be an excellent development. I wonder how many stations need to establish a country-wide survivor comms network?
The unknown quantity that is the industrially generated "radio noise" we have to endure currently is probably the only thing preventing a real, worthwhile radio comms. Plan.... The day after I spoke very clearly with an Orkney operator on 20 watts, I had difficulty reaching Oxford using double that power.... That's how much inconsistency we have at present... Not including atmospheric conditions, skip, ground wave variations and sun cycles Etc..
As for triangulating SSB locations, your right when you say they "can" be triangulated.... But You need long transmissions, mobile detection units many miles apart, multiple operators and more equipment than the electrical usage could justify in a SHTF scenario. So for most people's purposes, with short messages to preserve power, and Pre-arranged contact windows, We'll be quite safe.
Sorry Lightspeed... Missed a couple of answers.
The setup was a 1970s "superstar" mobile transceiver and a 3/8 wave mobile antenna, on a 110 Land Rover and the frequency was somewhere close to 27.555 MHz on the upper sideband, because that fitted the antenna's optimal tuning at he time.