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Re: [Discuss-gnuradio] Part 15 and Gnuradio...

From: Dave Emery
Subject: Re: [Discuss-gnuradio] Part 15 and Gnuradio...
Date: Thu, 19 Dec 2002 16:52:35 -0500
User-agent: Mutt/1.4i

On Wed, Dec 18, 2002 at 04:00:54PM -0500, ed wrote:

> ** screed mode on ***   at the risk of sounding alarmist, don't 
> underestimate what the FCC can enforce.  after successfully banning the 
> u.s. sale of radio receivers that covered 800MHz analog cellular 
> frequencies to non-government users, they proceeded to ban the sale of 
> downconverters that allowed UHF receivers to receive 800MHz analog cellular 
> frequencies.  at least one company (GRE) was forced to stop selling their 
> downconverter.  then the FCC successfully forced another company 
> (Optoelectronics) to take their 800MHz bandpass filter off the 
> market.  these were hobby electronics products, not mainstream consumer 
> electronics products.

        I feel most relieved on gnu-radio not to be the lone voice in
wilderness saying this to an audience that thinks I am an alarmist
nut or worse a fed agent provocateur.

        Nice to have someone else put out the same unpleasant message.

        I would, however, differ with you in a very subtle point - I don't
think it was the FCC that pushed for any of this.   I suspect that people
inside that organization realize the futile idiocy of attempting legal
rather than technical controls on radio listening.

        But they have been under the gun in Congress (Billy Tauzin at one
point was on the warpath) for not doing anything about the radio
privacy issue and almost inevitably this means that senior management
has had to see to it that the rules were tightened.   

        And this was especially true back a few years when Heather Wilson
sponsored a bill (HR514) that would make the FCC responsible for enforcing
radio privacy rules (and change section 605 to make merely listening
a crime rather than listening and disclosing).  The bill passed the house
but was blocked in the senate - several times in fact.

        The FCC's response to this was to produce the tightened scanner
NPRM (with help from Uniden) and make very clear that they regarded any
cell enabling scanner mods as actionably illegal if done as a business.

        I think a lot of this was that the FCC did not want to spend
its very very limited enforcement resources on busting scanner listeners
with modified scanners or cordless phone frequencies in their radios.

        It is my not very educated guess that the driving force behind a
lot of the DOJ actions is the prosecutor in the BNN case who has a bug
up his ass about evil "electronic voyeurs" and is now in the DOJ and
pushed for the anti radio hobbyist CSEA language that wound up in the 
Homeland Fascism and pretend security bill.

        And there are some very ominous and very recent signs.

        I follow and occasionally buy radio gear and test equipment on
eBay.  And I noticed that this very week (starting with the 15th)
the search term "selective level" turns up the null set.

        This is surprising as for at least the past two years there have
been a steady stream of antique HP SLMS gear (3586s, 3746s and the odd
312), Rycom SLMSs, and some Wangle and Gotterman gear on eBay.   Can't
think of any interval when there wasn't between 3-10 of the things up
for bid.   This is no surprise as use of FDM-SSB mux for telco purposes
has almost completely ended (mostly by 1991 in fact) and use of
FM-FDM-SSB analog microwave links for government and commercial purposes
is rapidly declining due to the fact that replacement parts and support
is drying up or has altogether dried up and so people with analog
microwave plant in the past have junked it and replaced it with either
fiber or digital radio, thus obsoleting their need for precision level
and frequency measurements and making their SLMS gear obsolete and

        So lots of the instruments have shown up on eBay from many
sources in ones and twosies.

        And frankly it is hard to see how such equipment is very 
dangerous as all the instruments are are precision fully synthesized 
tunable HF SSB receivers with extremely accurate and precise signal
level measuring capability and the ability to measure the frequency and
level of a a carrier buried in noise or other signals.   And some of us
have in fact used them as HF SSB receivers for various projects
including ham digital voice stuff.  Hard to buy a fully synthesized HF
radio with .1 hz tuning steps for say $150 anywhere else.

        But 25 years ago a Mitre scientist wrote a paper about the 
vulnerability of the then analog based US telecommunications network and
described how one could tap the transcontinental coax cables or point to
point microwave links using a suitable receiver and/or amplifier and tap
and a selective level meter.   I suspect the guy in typical academic
fashion never thought about all the ham and ex-military HF SSB receivers
that were widely available even back then - one hardly needed to buy a
$25K SLMS when a $300 hamfest special would do just as well or better.

        And so when I see at least possible evidence that someone has
decided to start controlling the market for test equipment that could be
used for darker purposes, I cannot help but think that some  technically
ignorant muddle headed DOJ type has suddenly decided that the humble SSB
receiver SLMS is a dangerous hacker tool that should be made illegal in
the hands of the public because he read that 25 year old classic paper
and doesn't know better.
        And done so this week.   And the fact that they seem to be
controlling SLMSes on eBay suggests a blunderbuss brute force approach
as anyone seeking to demodulate one of the remaining FM-SSB-FDM
microwave signals would likely not even want or need a piece of
precision test equipment when his full coverage ham transceiver with its
digital IF filters is already available and convenient for the job.

        Certainly someone seeking to intercept traffic on a antique
analog microwave link would likely not need the precision level  and
frequency measurement capabilities of a SLMS, these are very useful for
maintaining the link and multiplex gear but of little use to a listener
who merely wants to hear what is being sent.   And  there are many
legitimate lab uses for a device with the capabilities of a SLMS - like
calibrating test equipment and measuring the performance of mixers and
filters and amplifiers.   So one hates to see them criminalized -
especially as up to this point only honest to God bugging gear (bugs and
taps and so forth) and POCSAG decoders have been  made illegal under 18
USC 2512 and not anything as general as a general purpose wave analyzer
like a SLMS.

        And if SLMSes fall will spectrum analyzers, service monitors,
and many other kinds of gear such as PROM burners be far behind...

        And I might also not that the much more abusable wide coverage
microwave receivers that turned up on eBay pretty regularly have been
damned scarce there since early November as have a number of other
related items.

        Dave Emery N1PRE,  address@hidden  DIE Consulting, Weston, Mass. 
PGP fingerprint = 2047/4D7B08D1 DE 6E E1 CC 1F 1D 96 E2  5D 27 BD B0 24 88 C3 18

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