Saturday, June 20, 2009

GB3IM Links to the Internet and gets new equipment.

Today’s report is as follows:

GB3IM’s radio on Snaefell has now been replaced with a Simoco PRF1060 base station. This has improved receiver sensitivity and has also increased our transmitter output power. Initial contacts via the new radio have been very encouraging.

This activity brings two of the three Isle of Man UHF repeaters “on-line” with internet linking facilities
From now on, access to GB3IM will be by means of CTCSS at 110.9Hz only. Tonebursts will have no effect.

The Snaefell repeater is connected to the other Isle of Man nodes (and, from time to time, other AllStar or Echolink nodes) by means of an uplink radio located in Bride. For stations working through Snaefell by radio, the following points need to be noted:

· The repeater itself (i.e. the box on Snaefell) has no “Hang” time.

· When your transmission ends, the uplink radio is keyed in order to send a “Pip”. Consequently, if you transmit before, or during the “Pip”, you will be doubling with the uplink radio and may not be heard.

· When the repeater is linked to other internet nodes, it is important to allow time for the remote link radios to become ready. Please wait until after the pip before responding. Also, it would help “breakers” if you would pause a moment after the pip to provide a gap.

These points only apply to Snaefell and then, only for so long as it is “Uplinked”. We hope to install a control system on-site in the near future, which will remove these requirements.
GB3IM’s Echolink node number is 464453.

Node Status can be viewed at: for Snaefell and for Bride.

Stations wishing to set up outgoing Echolink or AllStar Link connections are encouraged to contact GD4HOZ for instructions. At this early stage we need to take care that we don’t end-up being linked to other repeaters without realising it, and that those who set-up links take care to tear them down again after use. As time passes and experience is gained, things will become clearer for everyone.

Noted Issues

1. I apologise in advance for the “wordy” node linking announcements. These are already proving to be a pain and I hope to be able to remove them in the near future.

2. When Snaefell receives a broken transmission, the software on the uplink sends a “pip” immediately after the repeater drops – which only takes a couple of hundred milliseconds. The sending of the pip takes approximately two seconds, during which time the incoming mobile will probably be “flattened” by the uplink. This leads to unnatural sounding breaks in a transmission which, under other circumstances, would just be a little fluttery. The system is oversensitive in this area and I am looking at ways to reduce the problem. When a PC is installed on Snaefell, and control then becomes local, this issue will go away, so it is hopefully only a short term problem whilst we are using an uplink.


No comments: