[R-390] Synthesizer Phase Noise
rbethman
rbethman at comcast.net
Sun Aug 16 16:54:43 EDT 2009
Tisha and others have pointed out the noise levels inherent with the
external synthesizer.
However, we have to remember that these were used with antenna systems
that we could only dream and drool over.
One particular receiver site of infamy, isn't very far from me. I do
remember when it was still up and running. When you drove up the road
to get to the Guarded entrance, you drove for at least a quarter mile
along a massive curtain array. That was only ONE of the VERY large
number of antennas that were visible from the road. The entrance road
to the actual road, even had a firing range situated between the curtain
systems and the Guarded entrance.
Considering that this was a Rifle range, you "may" begin to get a feel.
Just as you came to the guard, you could observe three or four RLPs,
(Rotating Log Periodics), that were about 70 foot up in the air, and
from the rear elements, 3MHZ was certainly within reason.
When you use an antenna system(s) like this, noise becomes a non-issue.
The gain of these systems had to be unreal. But, that is what they were
there for. Simply to listen, record, store, and pass on to those places
with initials.
BTW, those curtain arrays were strung on poles the tops of which were
WELL above the top of ANY power pole in the vicinity. They were
obviously Class 1 poles!
Bob - N0DGN
Tisha Hayes wrote:
> I had my doubts about the capabilities of the synthesizer just by looking at
> the block diagram and "imagineering" how they would do it. It is not
> surprising to hear that phase noise was a problem.
>
> Someone could create a similarly functioning external synthesizer for the
> R-390A using a variety of techniques with digital IC's by why bother?
>
> Tisha
>
More information about the R-390
mailing list