InterceptRadio.com Forums

http://www.theolympian.com/2011/09/06/1 ... akens.html

so they say, anyone have any thoughts on this? Wondering as far as simplex is concerned and one of the rail speeder groups I belong to will have to upgrade soon.

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"I was installing un-programmed radios"

Narrowbanding: The epitome of government creating a windfall for radio manufacturers at the expense of taxpayers and businesses.

That being said, if the powers that be had half a brain they could have made T-Band nationwide during the DTV transition. This would have brought instant frequency relief to most of the nation. As for the few urban areas with existing T-Band, the migration of some public safety agencies to 700mhz would free up plenty of bandwidth.

Getting back to the real world, use MURS or GMRS. Narrowbanding applies to Part 90 radios, not part 95. Unfortunately it appears the FCC may attempt to narrowband GMRS in the future (see NPRM WT-10-119).

Channel 1 151.625 MHz

Channel 2 151.505 MHz

Channel 3 158.400 MHz

I guess we can find a WB freq if the signal is degraded.

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"I was installing un-programmed radios"

Narrowbanding does not reduce RF in a given area. The SNR is reduced however. Thing is that most radio systems were overbuilt. Those that were not.... Well lets just say they were not forward thinkers... :twisted:

Our narrowbanded systems have not seen that big of a hit. A recent document (posted on this forum) from a railroad entity seems to agree with our findings...

What is going to hurt is the fact that these new "channels" will occupy areas of the spectrum closer to our frequencies causing higher potentials for interference.

Digital is another problem all together. A company decides to put digital systems on frequencies already occupied by another's analog system and they expect it wont interfere???

Digital always occupies the entire allowed modulation on a channel. Analog does not.. We learned the problems this can cause with Nextel... Remember them?

The lower grade portables and mobiles do not do selectivity very well at all. Clicking the 12.5kHz button does not fix this. Im not sure the higher grade (more expensive) units have solved this either...

I should have become a master brewer! Politics of radio suck!


/soapbox

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"A well regulated breakfast, being necessary to the healthy start of the day, the right of the people to keep and eat food shall not be infringed."

And it's not like the FCC didn't warn users. How long ago did the FCC make the ruling?

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I generate Board Warnings

Does anyone know if these newly licensed freqs have anything to do with the upgrade?

THURSTON 9-1-1 COMMUNICATIONS WPTK797 458.33750
THURSTON 9-1-1 COMMUNICATIONS WPTK797 453.63750
THURSTON 9-1-1 COMMUNICATIONS WPTK797 453.33750
THURSTON 9-1-1 COMMUNICATIONS WPTK797 453.21250
THURSTON 9-1-1 COMMUNICATIONS WPTK797 453.33750
THURSTON 9-1-1 COMMUNICATIONS WPTK797 458.33750
ADCOMM Engineering Company WPTK797 458.33750
ADCOMM Engineering Company WPTK797 453.63750
THURSTON 9-1-1 COMMUNICATIONS WPTK797 453.33750
ADCOMM Engineering Company WPTK797 453.33750
ADCOMM Engineering Company WPTK797 453.21250
THURSTON 9-1-1 COMMUNICATIONS WPTK797 458.63750
ADCOMM Engineering Company WPTK797 453.33750
THURSTON 9-1-1 COMMUNICATIONS WPTK797 458.21250
ADCOMM Engineering Company WPTK797 458.33750
THURSTON 9-1-1 COMMUNICATIONS WPTK797 453.63750
ADCOMM Engineering Company WPTK797 453.33750
THURSTON 9-1-1 COMMUNICATIONS WPTK797 453.21250
THURSTON 9-1-1 COMMUNICATIONS WPTK797 458.63750
ADCOMM Engineering Company WPTK797 458.63750
THURSTON 9-1-1 COMMUNICATIONS WPTK797 453.33750
THURSTON 9-1-1 COMMUNICATIONS WPTK797 458.21250

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Pro-97|Pro-106|Pro-107|Pro-508|BCT15X|BC346XT|Satellit 750|S450DLX
Thurston County, WA

Such is life when using "narrower" band FM... Trick is to build a receiver IF strip with correspondingly narrower bandwidth, then the noise floor in said receiver would be lower and one should in theory get back some of what is lost... as you are amplifying less "atmospheric" noise... although much of the noise in VHF/UHF systems is actually generated by the first active device in the receive chain... Which is why Single Sideband at around 3khz of occupied bandwidth outperforms 16khz bandwidth FM any day of the week, by around 12dB!!! Hams don't use NBFM for EME, obviously.

The big problem with simply "switching to SSB" is oscillator phase noise and stability... and the higher parts counts required in the transmitter and receiver circuitry, along with the necessity of using DSP, in part to permit automatic netting of the receiver to the transmitter to prevent translation errors.

That being said, I agree with Rich that "T" band expansion nationwide as part of the DTV transition along with most of the "conventional" users of VHF/UHF spectrum vacating it in favor of SMR/cellular/PCS based systems means that the "refarm" is essentially unnecessary...
The FCC has been "threatening" this for over a decade now anyway...
If they wish to continue to operate "in the public interest" the FCC is going to have to do a much better job of looking into their "crystal ball"-- and send all their "lawyers" to RF engineering school!!! Had this been done a quarter century ago many of the politically motivated engineering mistakes wouldn't have been made.

Eric
KB7DQH

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That is how the people at DARPA think. they take things and use them in unconventional ways, to see what happens.