--- On Fri, 9 May 1997 08:34:50 +0200 "Heck, Stefan" <[email protected]>
wrote:
>System requirements for RE102
>
>When performing the emission test RE102 according to MIL-STD-461/462D we
>observe that the test system noise floor is at some frequencies just
>below the most stringent limit (navy mobile and army). This is when we
>use the bandwidths prescribed by the standard. We can lower the noise
>level when we reduce the bandwidth.
>
>Has anybody similar experience? How can we lower the noise floor and at
>the same time fulfill the standard requirements regarding the setup? We
>are using brandnew and high standard test receivers and antennas.
>
>Any hints are really appreciated!
>
>
> Stefan Heck
-----------------End of Original Message-----------------
Stefan:
It would help us to comment more accurately if you gave us a list of
the equipment (analyzers, antennas, cables) which you are using.
You may need a good low-noise pre-amp. Look for something with less
than a 1 dB noise figure. My favorite vendor is Miteq, in New York, USA. (They
have a web site.)
But first, check to see if you have antennas which are efficient enough
to have decently low antenna factors. Then, make sure you have very good, low
loss coax; no longer than necessary. Finally, don't rely on too much
automation. Verify that any computer system is actually correcting the data as
you assume.
If it does come down to your receiver (analyzer) not having enough
sensitivity, I would be surprised. Any combination of HP, EMCO, AHS, Singer,
R&S, Tek or Carnel gear (that I have ever used), made in the last 10 years,
will let you read to below 461's limits. I just finished an RE102 test where I
had a limit of 3dBuV/m in a short band around 2100 MHz. My HP-8571A's input
sensitivity at this frequency is almost as good as my Miteq pre-amp's 0.6dB NF,
so I didn't bother with the pre-amp. Well, I did have to use a non-standard
narrower bandwidth, and I used a higher gain than usual horn antenna, and it
did take me about an hour to scan 100 MHz of spectrum, but the stock test
equipment did get the job done! (You WILL have problems using an NF-105 with a
VA-105 passive antenna and RG-58 coax.)
--------------------------
Ed Price
[email protected]
Electromagnetic Compatibility Lab
Cubic Defense Systems
San Diego, CA. USA
List-Post: [email protected]
Date: 5/9/97
Time: 3:22:16 PM
--------------------------
