On 12/20/2013 10:54 PM, Tony Hwang wrote:
Danny D. wrote:
On Fri, 20 Dec 2013 19:24:55 -0800, makolber wrote:

Also decrease the feed line loss... Is the radio mounted up at
the antenna?

Hi Mark,

Here is a picture of the mount when I had installed it:
http://farm4.staticflickr.com/3688/1...955239ba_o.jpg

The radio itself is the classic Ubiquiti Rocket M2:
http://store.netgate.com/Assets/Prod...KETM2%20US.jpg

That radio is clipped directly onto the back of the dish:
http://www.ubntstore.eu/images/detai...tmp_FEWrpH.jpg

One mistake I made was to use non-shielded cable, so, there's about
75 feet of the plenum stuff outside going from the roof to the
first floor office where the router and POE lie.

From a practical (noise) standpoint, how much do you think that
matters?

Hi, B4 you ask that question think about shield? Why do you think we
use shielded cable in AF or RF cabling(wiring) CAT 7 spec. ethernet
cable is best one. I believe your noise is radio related unlikely
Ethernet cable related. Looks like your radio is repeater? All in all
if you have reliable connection, what's the worry? One way of
increasing signal strength will be using a bigger dish or did you
picked best height of the antenna. The higher the better is a myth.
Is it LOS install.?

Way back when I was working on microwave, troposcatter links biggest
one was troposcatter link shooting from Nha Trang, S, Vietnam over to
Thailand. Triple diversity, antenna was 120 ft. square parabolic
pair. Nitrogen gas filled wave guides were used. No coax. SWR was
around 1.2. One night VC rocket sharpnels made some holes in wave
guides plumbing, SWR went upto about 1.4

Tri diversity is based on antenna spacing, frequency, polarization.
RX was parametric cavity tuned preamp, and all tube based RX, TX was
10W TWT exciter to 10KW water cooled Klystron driving 100KW bigger
Klystron also with water cooled. HV on them were around 27KV DC.

This all became obsolete soon when RCA launched first Commsat. That
was end of my career in RF telecomm. going into Digital Data comm,
main frames, etc. Worked on autovon/autodin, Arpanet(origin of
Internet). Now I am no good any more, things changing too fast to
grasp all.


Nonsense, when you quit learning you're dead. You know how to learn
which is a quality many people lack. ^_^

TDD