[ANSS-netops] radio frequencies

[Croker, David]

Hi Greg,

Thanks for the info.  I'm glad you are still working to meet the needs of
the RSN's!

I do want to clarify that USGS cannot ask for RFA's in nor are allowed to
use the 200MHz band.  NTIA's band plan does not allow federal users in
217-220 anymore.  The RSN's that do not use USGS for their RFA's should
still be able to request those frequencies through the FCC.  Furthermore,
USGS is restricted to 12.5kHz in the VHF and 400MHz bands.

As for the chatter, we are trying to get clarification from Reston and NTIA
on what is really happening.  On first blush it appears that rather than
losing frequencies in the 162-174MHz band, NTIA has defined a new band plan
that would require many of us to move to different center frequencies.  The
NTIA band plan supplement says that users are supposed to conform to the
new band plan by Jan. 1, 2019.  Unfortunately we have not gotten any
feedback yet on what's real.  Thanks go to Tom Yelin for first discovering
this.  I know you've been working locally with Phil Raymond on the VLF VHF
radio.  We may be knocking on your door soon!

Dave
------------------------------------------------------------------------------------------------------
USGS - Earthquake Science Center - NCSN Field Operations Manager
David S. Croker                                                    office
(650) 329-4697
345 Middlefield Rd, MS 977                                      fax (650)
329-4732
Menlo Park, CA 94025                                             cell (650)
465-4334
email: croker at usgs.gov           Quake info: http://earthquake.usgs.gov/


On Mon, Jan 11, 2016 at 8:15 AM, VLF <vlf at cablerocket.com> wrote:

> I have seen some chatter recently regarding loss of VHF channels due to
> NTIA reallocation operations. I would propose that any who wish to continue
> analog operations consider the 217-220 MHz spectrum. CERI at the University
> of Memphis has used these frequencies for the past 35 years in the analog
> New Madrid network (65 stations). The band is pretty free of competition,
> however channel 13 TV is right below the band with typically maximum power
> of 316KW. It is clearly the thousand pound gorilla in the room. Vertical
> polarization of antennas and cavity filters are required on telemetry paths
> that are anywhere near one of these transmitters. In rural areas it is
> usually clear sailing though. Our company has teamed up with Hamtronics (a
> long term ham equipment supplier) to produce a radio specifically for
> telemetry use by modifying the modulation circuitry of their equipment for
> low distortion transmission( <1%) of analog signals. The current radio is a
> synthesized unit with the three programmable frequencies and a  variable
> power design that operates over a 100 to 1500 mW output power range.  The
> receiver noise is around .3uV and the modulation bandwidth i2 300 to 3500
> Hz. Frequency stability is typically better than 200Hz over a temp range of
> 0 to 120 degree F. The radio does not require custom crystal (or crystal
> compensation)
>
> If there is sufficient interest, we will produce a new custom, frequency
> agile, 217-220 MHz  analog radio system that will meet FCC emission masks
> while allowing full 25 KHz bandwith NBFM operation, thus allowing for
> unhindered use of all standard IRIG analog telemetry frequencies, This
> radio can also be made available for 12.5 KHz bandwidth use if necessary.
> We will try to market these radios in as cost effective way as possible
> which will depend on the quantity required. Small samples of the current
> radio in production are available for evaluation for $1200 per pair.
>
>
>
> VLF Designs
>
> 1621 Bella Vista Dr.
>
> Jackson, Mo. 63755
>
> 573-204-1286
>
> vlf at cablerocket.com
>
> vlfdesigns.com
>
>
>
> _______________________________________________
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>
>
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