Hi

I would like to improve my airband reception for my local airfield
(Sywell). Currently I can hardly make out what the tower is saying and
struggle with 75% of aircraft as the voice signal levels dissappear
into the noise levels. Most signals do activate the squelch ok, but
the audio noise levels are just to high.

My current setup consist of a dual band (2m & 70cm) vertical fiber
glass antenna (I can't find the exact details at the mo) on a 2.5m
meter pole which takes the top of the aerial just above level with the
neighbouring houses roofs. It then feeds into the loft with about 3 M
of Y[1] cable, through a small lightening discharge unit (which I still
need to put the ground connection in for) and then through 3m meters
more of Y[1] cable. Then inside the loft room it goes into a panel
mount BNC connector and through 1M of RG-59/U cable before going into
the AOR AR900 scanner.

[1] It has no numbers written on it, but it is a 1cm diameter coax
cable
original bought for amateur radio use.

I suspect the loft room is fairly RF noisy as it is my study including
two computers, monitors, ADSL, wireless 802.11b etc. Connecting the
scanner to mains (via it's transformer, or battery makes no difference.

I'm looking for a rough idea of how much the following options would
improve my reception experience against the cost / difficulty of
completing those changes:

1) Change aerial (must also be able to Rx & Tx on 2m and 70cm)
2) Raise aerial by 1m or so, so that it is above neighbours roofs.
3) Change aerial feed cable
4) Ground the lightening arrestor (something I know I need to do
anyway)
5) Change Rx end BNC to BNC cable (is that the right kind of cable?
Impedance mismatch?)
6) Change panel mount BNC connector (does this let noise in due to
short unshielded bit of inner cable or impedance mismatch?)
7) Add a band pass filter for airband at the Rx end
8) Add a pre-amp for airband as close to the aerial as possible

Any other suggestions?

Thanks in advance
Kev