[amsat-bb] Questions on practical aspects of coax and preamps.

[Curt Nixon]

Good Morning All:

So, after this last week of ISS fun, I have the bug to upgrade into some 
simple satellite work.  I will be confined to simple FM untill I can 
upgrade to all-mode rigs.  My question is on coax and preamps.

I will use a pair of vertically polarized yagis to begin with.  One for 
144MHz and one on 70cm.  I have some LMR 400 I got for the ISS project 
on 144 but it is so stiff, I didn't use it. 

1.  If you use LMR 400, do you add flexible sections at the antenna end 
and in the shack, using LMR400UF?
Or, should I just use all UF and forget the additional connections?  The 
cost of the additional connectors (N) both in loss and $$ is probably 
advantage $ for UF.  Not sure about the loss potential for adding two 
sets of interface connections.

2.  With a 5-7 element yagi on 144, is it really necessary to use low 
loss coax as a opposed to 8x or 8x mini.
Runs here are 35' if munted at 12' and 60' if mounted to roof tower at 
about 20'

3.  On 70cm, I plan to add a mast preamp, but will use the yagi 
"barefoot" to begin with.  With a preamp at the antenna, is low loss 
coax still required or can the cost increment be put to better use in 
the preamp to begin with?   The preamp of course also gives a convenient 
place for a connector interface from stiff to flexible if desired.

Anyway...I appreciate input from those that have been there and done that.

Thanks

Curt
KU8L