Welcome to the home of the UK152 PMR 446 Internet Gateway in Hornchurch.
This page is just for some information on the gateway, and some pictures
of the setup. This repeater was first setup on September 24th 2003,
and is not currently 24/7. It will be up most weekends, and weekday
evenings, which is when most activity is heard on the repeater network.
To learn more about the PMR446 gateway network, visit www.446user.co.uk.
2nd December
2005 -
Hello all. Gateway hasn't been on for quite a while, as I use my pc
for music etc, so cant really have it running too often. I might set
up a dedicated pc just for it soon. It is on today though!
| Must
say big thanks to Simon CZ001 in Prague for writing an article
about the gateway in the December 2003 issue of Radio Active magazine! |
|
|
The setup in the
attic. |
|
Above is the router
used to connect UK152 to the main eQSO
server provided by 446user.co.uk. All the repeater stations
are connected to the main server, and are therefore all linked
together. The connection at this end is 288Kb/s up, 576Kb/s
down ADSL connected to the Pipex network.
|
This pic shows how
high up the radio is in the loftspace. Its as high as it can
get without getting too close to the tiles and rafters, and
it performs well.
|
|
Because
the gateway is using a BT Freeway PMR with no vox, I had to
make a com port keyer (more on this here)
My local Maplin did not have the 4N25 optocoupler in stock,
so I went on the hunt in my cupboard full of old printed circuit
boards. Quite easy to spot the 6pin optocoupler ic, and it
wasn't long before I found one. It was in an old Amstrad switch
mode power supply, and has the part number PS2653. A quick
search of the part number in google, confirmed that it was
indeed an optocoupler, with the same pinout as the 4N25 that
was required. Not knowing if it would work, i built the circuit
anyway as seen below, coupled it up to my DB9 communication
port 1 on the pc, and attached a multimeter to the output.
And wehee, it works! Although I did eventually get the 4N25,
and put that in, just so it was all 'proper'.
Ooh, I found a
DB9 plug at last!
|
The finished Optocoupler.
(com port keyer)
Optocoupler underside
Some scans
of this are also available: Top
| Top with
pointers | Bottom
| Bottom
with pointers
Above is how the
rig keying has to be setup. This is for my own reference so
I know how it was set when working! |
This is where all
the wires meet before going up into the loft. You can just see
the 10uf capacitor blocking the DC from the radio. |
This diagram shows how
I wired the PC to the PMR446 radio.
All cable is shielded,
apart from the keyer cable, and the power cable which is not shown.
The PMR radio
is powered by the psu seen here on the left. Its a regulated
power supply, which can give the voltages: 3v, 4.5v, 6v, 7.5v,
9v and 12v, at a small 300mA. It is set at 6v, which is perfect
for the freeway, as it usually takes four 1.5v AAA batteries.
300ma doesn't seem much, but it is just enough to power the
radio on transmit. Putting my multimeter inline, set to amps,
it read around 50mA on receive/standby, and around 290mA on
transmit.
Also pictured below is a dipole antenna tuned to 446MHz which
is for RECIEVE ONLY! It's amazing how many stations you can
pick up when coupled with a PMR radio.
This is just a VHF dipole and small scanner
antenna on my house.
|
|
Click here
to see a coverage map. I shall get more detailed readings once I have
done some tests. To hear the stations idle announcement, which is
broadcast every ten minutes whilst idle, click here.
Sounds very official! So if youre in the area and cant get a response,
you only have to listen 10 minites so you know if youre in range.
You can
download the eQSO software from the 446user.co.uk
website. Download "eQSO for PMR446" to listen and talk through
your computer, or "eQSO RF GATEWAY for PMR446" if you wish
to set up a repeater. You must contact 446user.co.uk before setting
up a repeater, so they can issue you a callsign, and add you to the
database.
|
