[Tech-Assist] STL problem now critical

[Mike McCarthy]

Couple things...

Hamtronics...generally 2nd tier product.  Might work in a pinch, but 
generally not professional grade.  If on hand, use it as a test device 
in an experiment. But don't leave in permanently.

Tower top location of a 950 STL pre-amp is generally a poor choice for 
broadcast with a few  exceptions. A good pre-amp on a signal with 
already reasonable S/N will not degrade the signal any farther on the 
ground than if it were on the tower.  Tower top locations are more 
critical where the signals are already very weak (LMR and cell) and the 
pre-amp's themal noise would not aid in increasing SINAD if it were on 
the ground.  There is also the risk of lightning damage. That's not to 
suggest it can't be done.  But there are already an number of weak links 
up there, why add another if it's not needed.

I can think of a few exceptions.  A 1000ft. high dish and run on 7/8" 
line on a 30 mile link.

FWIW, My 33 mile hop with the RX using 950ft. of 7/8 line employs a ARR 
GasFET located in the TX building. My 9002 system derives nice happy 
-59dBm of signal with low BER.  Tower top...not needed...on either 
antenna.  Solid like a rock...except during thermal inversions.

Cheers...

MM

On 3/28/2012 10:32 PM, Chip wrote:
> Just stay away from Hamtronics.  It is junk.
>
> One other thing -- the pre-amp needs to be at the antenna or the noise
> figure won't be improved at all, and will most likely get worse.
>
> --chip
>