[aprssig] Base antennas and a couple other questions

[Chris Rose]

A recive only or 99% receive antenna for APRS that
works great is a copper cactus.  Not heavy and easy to
use or stow for transport.  Cost less than $15
depending on component costs.  No need to spend mega
bucks for an antenna that isn't needed for TX.  

Now, putting rigs in boxes for transport and use is a
good idea.  I have two set up for use for ARES.  Holes
for an SO-239 bulkhead barrel connector for antenna
and a square hole for a power connection make the rigs
inside self contained and protected.  Just make sure
you have room inside for air circulation around the
heat sinks.  

Shielding them from commercial RF frequencies needs a
notch of some kind or other RF filter that can be
purchased commercially to place between the TXRX and
its antenna.  Anywhere from $40-$100 range depending
on who makes them.  DCI is one brand and their ads are
in CQ or and QST. 

An antenna for the portable repeater rigs needs to be
a good one for the voice comms links.  Diamond X-50 is
a 4.5' fiberglass stick that mounts with its own base
and two large aluminum u bolts for large diameter
pipes(you can make a smaller pipe by using mast
available at Radio Shack or an appliance store that
still sells TV antennas).  This antenna should be
available for about $95 depending on who you buy it
from.  Dual banded for 2M and 440.  Has its own SO-239
connector on the base.  This antenna may have a
commercial equivalent for your 155mhz use.  
Consult Diamond or Comet/Maldol for their prices.  I
hate to suggest MFJ but they may have something to use
also for 2M/440 as well.
Commercial antennas like stationmasters (Decibel) will
be better for gain but will bust your budget wide
open.  I won't suggest them for this application
unless you get a grant from someone.  

73,
Chris 
KB8UIH

--- Josh Keller <jeepin95 at comcast.net> wrote:

> Seeing as how I am the most familiar with radios in
> my SAR group I have 
> been assigned to come up with a few different things
> they want to 
> purchase. I'm fairly new to all this radio stuff so
> I don't know a whole 
> lot about it, which is why I'm asking here. 
< C U T >