At 1:15 PM +0200 4/30/01, Novarex Enterprises Ltd. wrote:
Dear Treggers,
FCC Part 68 specifies quite a large number of bands between 20 Hertz
and 10 MHz for which characteristics are defined and need to be
tested.
Can any of you give me a lead to a suitable tunable bandpass filter
that is capable of supporting all of the Part 68 requirements, or to
an acceptable method of performing the tests using a filter with a
wider and less accurately bounded frequency band? In particular, for
example, the need to make measurements in the extremely narrow band
of 3,995 to 4,005 Hertz, as specified in Part 68.308(c), appears to
be unanswered using equipment generally available on the market.
I have been looking at the Krohn-Hite 3945 tunable filter, which
covers the spectrum of interest. However, even this quite
comprehensive filter is not capable of meeting the 3,995-to-4,005
Hertz requirement, and I believe that it does not quite have the
capability to exactly set some of the other frequency ranges
specified in Part 68.
Thank you in advance for all responses received.
Regards,
David Drori
Novarex Enterprises Ltd.,
PO Box 45178,
Room 204, 2nd Floor, Park Center,
Hamarpe 1,
Har Hotsvim Industrial Area,
Jerusalem 91450,
Israel.
Tel: +972 2 540 0168
Fax: +972 2 540 0169
GSM Cellular: +972 54 828011
E-mail: [email protected]
David,
I have successfully used HP 3582A and HP 3585A Spectrum Analyzers to
make the tests. The 3582A is very good below 25Khz and the 3585A
below 40Mhz. Both are used in the standard spectrum analysis mode
and also set up as bandpass filters. Word of caution, both only have
a dynamic range of 80 dB.
Duane J. Marcroft
Telecom and Data Communications Consulting
[email protected]
