I have used both star and daisychain networks with TR.
For the daisychain network we use ordinary 2 core mains flexible cable as
this is robust enough to be trodden on and driven over on field days. At the
DB9/25 end there is a short lead to a female phono socket with a male at the
far end of the cable. I have paralleled DB9's and 25's so that it does not
matter what socket is on the machine you can always plug in without having to
find an adapter. The maximum length I have use for a single hop in the chain
is 50 metres. On the UK Field day we did not experience RF problems but the
power limit on HF for this event in the UK is only 100 Watts.
I have also built star networks using telephone extension cables. A short (5
metre) cable is cut in two and DB9 connectors attached to the fresh free ends
to make a cross over cable. If you are making up more than one cable ensure
the connections are identical in case you get the halves mixed up. The cross
over cables can then easily be extended by adding in ordinary extension
cables that are available in 5, 10 and 20 metre lengths. The telephone
connectors are latching so do not come apart too easily. The maximum length I
have
tried with these extension cables is 35 metres. Again I have not tested these
in a high RF environment.
If you want more machines in a star network then you need one dongle for
each machine over the first two. The dongle comprises one female and two male
connectors connected with a loop through to simulate the daisy chain. You can
also mix start and daisychain using this technique.
The protocols in the software make the network reasonably robust. I have
simulated QSO rates of over 4000 per hour by replaying past logs (TR READ)
The
other receiving machines were able to record all the QSO's except when one
was using 'save to floppy' as tertiary backup. NOTE:- when one machine looses
QSO's all machines further round the loop (other than the originating one)
also loose the QSO's I don't think my group are ever likely to get up to this
sort of QSO rate!
At simulated QSO rates of just over 400 per hour all QSO's are recorded even
with floppy save turned on. I have not tried at intermediate rates to work
out when QSO's start being lost but this will be dependant on the machines in
use anyway.
I hope this helps
Regards
Malcolm
G0MIC
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