[time-nuts] GPS Antenna Cable Splicing

[Matthew Smith]

Hi Folks

I'm not so hot on RF stuff (actually not so hot on anything above
50/60Hz - only studied power stuff) so thought I should ask:

I have a few GPS antennae here, all with 5m (15ft-ish) cables on them.
For me, that won't get the antenna anywhere near the highest ridgeline
of the house.  (Australian "Federation Style" house - lots of weird bits
of roof all over the place.)  So, I need to extend the cable.

1) Can I actually extend the cables, or is 5m as far as I can go - all
these are active antennae.

2) My normal way of extending a bit of coax would be to splice in an
appropriate length of similar cable.  To do this, I would strip the
outer insulation for a couple of inches on both pieces, pulling back the
braid.  I would then strip enough of the central insulation so that I
can solder the two cores together.  I insulate this with tape or
heatshrink, then solder the two braids together, wrap the whole thing
with aluminium foil and use a glued heatshrink to case the whole lot.

I know that this method works for 10-Base2 Ethernet and UHF Television,
 but have no idea if is suitable for SHF stuff like 1.5GHz...

3) How far apart do I need to space my GPS antennae, or can they be
nearly touching?  I suppose it would be easier if I used a distribution
amp (assuming such things exist at this frequency), but that sounds
expensive.

Cheers

M

-- 
Matthew Smith
Smiffytech - Technology Consulting & Web Application Development
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