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[aprssig] Is there a place for APRS on 6 Meters?

Wes Johnston, AI4PX wes at ai4px.com
Tue Jul 28 21:56:39 UTC 2009


Lets also not forget that 9k6 is legal on 50mhz.  I had this same thought a
week or two ago... the closest low band tv station to us in SC is in Augusta
GA, but it's way up on 82mhz.  YAY!

Wes
---
Hitler gave great speeches too!


On Tue, Jul 28, 2009 at 17:14, Stephen H. Smith <wa8lmf2 at aol.com> wrote:

> --- A Six Meter Revival Is At Hand ----
>
> --- Is There A Place For APRS In It? ---
>
>
> With the shutdown of analog TV on June 12th, TV channel 2 RF has
> disappeared just about everywhere.   (ALL the TV stations indentifying
> themselves as "Channel 2" on digital in the major cities have "QSY"ed to UHF
> for their digital alter-ego.)  There are only 7 stations left physically on
> channel 2 in the entire country now!  All in smaller towns.  Here are the
> details copied from
>
>    <http://rabbitears.info>
>
>
> Actual
> Digital        RF        Display
> Channel    Channel    Callsign-City-State
>
>
> 2    3    KVBC-DT LAS VEGAS NV
>
> 2    2     KNAZ-TV FLAGSTAFF AZ
>
> 2    2     WLBZ BANGOR ME
>
> 2    5     KREX-TV GRAND JUNCTION CO
>
> 2    3     KOTA-TV RAPID CITY SD
>
> 2    2     KNOP-TV NORTH PLATTE NE
>
> 2    2     KJWY JACKSON WY
>
> What this means is that, for the first time since the early 1950s, 6 meters
> is fully usable in nearly all areas of the US.  All the mutual interference
> issues to-and-from channel 2 TV are gone.    Even in these seven remaining
> areas, the steep-skirted emission mask for the digital signal should mean
> far less trash below 54 MHz. Not to mention that any "slop" from the digital
> signal will appear more like random white noise rather than discrete
> birdies, squeals and buzzes in ham receivers.
>
> The S9+ noise level of sync hash and video buzz from the lower sideband of
> half-megawatt ERP signals on channel 2 that rendered 6M unusable here in
> southern California (and many other urban areas) has disappeared.
>
>
> When KCBS 2 here in L.A. finally turned off their chan 2 analog
> "nightlight" station  on July 12th, the noise floor on 6 meters immediately
> dropped from S-9 plus to S-0 on my TS-690.   [ A "nightlight" was an analog
> station remaining on the air AFTER the JUNE 12th digital transition,
> broadcasting exclusively an endless loop of information on the digital
> transition and how to install a digital converter box.]
>
>
> I am predicting a renaissance  of activity on 6M, now that we can actually
> HEAR something.
>
> Is there a place for APRS here?   Should we (can we) stake out a national
> APRS channel on 6M?
>
> Obviously, all-in-one compact trackers will be hopelessly impractical on
> this band, due to the size of antennas and effective groundplanes.
>
> On the other hand, I AM interested in the possibilities for APRS from
> mobiles on 6M.  Low VHF has far superior long-haul propagation
> characteristics in open county with far less of the rapid fluttering and
> chopping that mangles data on VHF and UHF at greater distances.  [There is a
> reason that Highway Patrols and State Police still use 39 MHz for rural
> operations...]  With the proliferation of all-mode "DC-to-light" 100W mobile
> rigs like Icom 706s and Yaesu FT-857s (both of which have rear-panel
> mini-DIN "data" jacks), the potential for long-haul open-road APRS on 6M is
> there.
>
> Not to mention the occasional DX excitement when the band opens. [If this
> solar ultra-minimum EVER ends....]
>
> Years ago, before APRS, I did some packet data transmission experiments on
> 6 meters from a mobile running a Kenwood TM-742 with 50 watts out, here in
> Los Angeles.  I was absolutely astounded at how the 6M signal would
> propagate over and around hills, and through canyons and passes that stopped
> 2M dead in a mass of multipath phase distortion.   The only down side is
> that there is far more man-made electrical noise on 6M in built-up areas
> than on VHF.   [Low-band Motorola Micors had noise blankers, VHF and UHF
> didn't...]
>
>
>
> ------------------------------------------------------------------------
>
> --
>
> Stephen H. Smith    wa8lmf (at) aol.com
> EchoLink Node:      WA8LMF  or 14400    [Think bottom of the 2M band]
> Skype:        WA8LMF
> Home Page:          http://wa8lmf.net
>
> JavAPRS Filter Port 14580 Guide
>  http://wa8lmf.net/aprs/JAVaprsFilters.htm
>
> "APRS 101"  Explanation of APRS Path Selection & Digipeating
>  http://wa8lmf.net/DigiPaths
>
> Updated "Rev H" APRS            http://wa8lmf.net/aprs
> Symbols Set for UI-View,
> UIpoint and APRSplus:
>
>
>
>
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>
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