Why radio receivers won’t tune 800-900 MHz

I had (and probably still have) a Radio Shack Pro-2006 scanner from the late 80&#x27;s. Even pre-Internet, instructions on how to bypass the cellular band block were easily found on Fidonet and local BBSes, and all it involved was removing a single diode.<p><a href="https:&#x2F;&#x2F;www.wentztech.com&#x2F;radio&#x2F;Equipment&#x2F;Pro2006&#x2F;pro2006mods.html" rel="nofollow">https:&#x2F;&#x2F;www.wentztech.com&#x2F;radio&#x2F;Equipment&#x2F;Pro2006&#x2F;pro2006mod...</a><p>It was really a golden time for snoop...er..listening to cellular phones because they were so enormously expensive, including per-minute usage fees, that only drug dealers, doctors, and the 1%-ers could actually afford to use them. So there was always interesting things to hear.<p>Ordinary cordless phones were much more affordable and fairly common at this time. They broadcast in the clear at 49 MHz (at least in the USA) and had no legal protections like the 800 MHz cellular phones.

Hi all, I am the author. I 1) have no idea how this made it to the top position, 2) now feel much guiltier about posting so infrequently, 3) apologize for the design of my blog being almost actively hostile to users, but then maybe that was the point?

I think the OP&#x27;s write up misses one very important piece of the puzzle: Politics.<p>Newt Gingrich who was Speaker of the House at the time got embroiled in an incident that was recorded from a cell phone conversation. <a href="https:&#x2F;&#x2F;www.cnn.com&#x2F;ALLPOLITICS&#x2F;1997&#x2F;01&#x2F;13&#x2F;tape&#x2F;index.shtml" rel="nofollow">https:&#x2F;&#x2F;www.cnn.com&#x2F;ALLPOLITICS&#x2F;1997&#x2F;01&#x2F;13&#x2F;tape&#x2F;index.shtml</a><p>Now fast forward to a few years later with the Patriot Act and metadata controvery that Edward Snowden exposed... same shit, different day...

*in the USA.<p>Radio receivers and scanners sold outside the USA, even if they are made inside the USA, have no restrictions. US manufacturers usually label these radios as &quot;export&quot; versions.<p>It reminds me of the early days of web browsers when &quot;export&quot; versions of Netscape and IE only supported a maximum of 56-bit encryption for SSL.

Cordless phones were more &quot;fun&quot; to scan since it was generally your neighbours you heard just because of the range of those things. Also baby monitors were (and probably still are) wide open. Literally a 24&#x2F;7 mic broadcasting for anyone to listen to.<p>Pagers were also easy to listen to. You&#x27;d get short messages without context. A lot were office to doctor or dispatch to tradesperson.

As a child in the 80s I was given an intellivision and a old (even in those years) ~13&quot; black &amp; white tv to play it on.<p>It had the ability to tune to the higher UHF channels 70-83 [0] which while planned for use in tv broadcast, never ended up being used, but they didn&#x27;t know that at the time of the construction of the tv set. The frequency covered by those channels were reallocated in 1982 by the CCIR worldwide convention, and covered approximately 806 to 890mhz.<p>What was most interesting to me as a young teenager in the early 90s about this particular tv set, was that I found out I could hear an occasional phone call when tuned to those UHF channels, even more so when I used the fine tuning nob.<p>On a side note, the tv set also allowed me to view scrambled channels on the cable system which I could unscramble to various degrees by turning the tuning nob at certain rates back and forth. I suppose modern 90s systems were not designed with my old tv set in mind.<p><a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Television_channel_frequencies#Americas_(most_countries),_South_Korea,_Taiwan_,_Burma_(Myanmar)_and_the_Philippines_2" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Television_channel_frequencies...</a>

Anyone have any recommendations on a &quot;modern&quot; digital trunking scanner? (handheld)<p>I have an old GRE PSR-500 which isn&#x27;t terrible, but I&#x27;m looking to replace it as it has next to zero software support for programming it and doing it by hand is a real pain.<p>You&#x27;d think in this day and age someone would make a scanner with a companion app connected to Radio Reference for programming. Would be nice to have bluetooth audio too.<p>FWIW, GRE stopped making scanners in 2012, and later closed down and sold off their scanner business to Whistler. Supposedly Whister were going to release a new scanner, the TRX-100, but cancelled it. Seems like handheld scanner technology is still stuck in the &#x27;80s.

I&#x27;ll never forget using grandpa&#x27;s police scanner trying to find interesting sounds and tuned to one of the ~1800 frequencies and shockingly discovering that the cordless phone we bought in ~2003 was completely unencrypted broadcasting in the clear at half of the frequency I was listening to. My mom was in disbelief and we bought a new phone with DECT shortly after. I was a bit shocked myself.

The article mentions the Oki 900. Here&#x27;s a Wired article mentioning how hackable it really was: <a href="https:&#x2F;&#x2F;archive.is&#x2F;AEq0B" rel="nofollow">https:&#x2F;&#x2F;archive.is&#x2F;AEq0B</a>

Back when analog cell phones were still a thing on the few scanners you couldn&#x27;t make a trivial modification to enable receiving the cellular frequencies (e.g. switch them into export mode) you could often just tune into some harmonic.<p>I wonder if truckers still call a lot of phone sex?

This blogpost is unfortunately barely readable on a small screen, because of the fixed line widths.

The requirement that scanners not be a silly modifiable to restore the AMPS bands was loosely interpreted. On certain older RadioShack scanners, you could unsolder some diodes on the main logic board and full coverage would be restored.

...And you could use a code on Motorola startac models to listen to these channels very easily. One of my hobbies was to do that when I was waiting for my girlfriend in the car.

Here is a nice image of the Canadian Frequency Allocations<p><a href="http:&#x2F;&#x2F;canadianspectrumpolicyresearch.org&#x2F;wp-content&#x2F;uploads&#x2F;2016&#x2F;08&#x2F;2014_Canadian_Radio_Spectrum_Chart.jpg" rel="nofollow">http:&#x2F;&#x2F;canadianspectrumpolicyresearch.org&#x2F;wp-content&#x2F;uploads...</a>

I had a weird situation 12 years ago. I got a tv for christmas. When I set it up it scanned for channels. It picked up channels with decimals in the high range and there were pay movies on but when they finished the channel would go dead. The next day I rescanned the channels because of fuzzyness and it picked up new channels with decimals. This time some of the movies were x-rated.<p>I would rescan daily usually in the evenings and watch what other people paided for. Thursdays and Fridays were good. During the day mostly kids movies.<p>In the mornings someone would watch a porn fast forward 10 minutes to one specific part.. slow down the video to play 2 minutes then turn it off. Very funny.<p>If you are in a building let your tv scan for channels in the evenings. If you see a decimal high channels you may have it too.

MAN THIS IS THE FASTEST LOADING SITE

&gt;not particularly difficult to intercept the call setup process from an AMPS phone and swipe its identification numbers, allowing you to basically steal someone else&#x27;s cellular service. You can imagine that this was popular with certain criminals with a need for untraceable but convenient communications.<p>and Kevin Mitnick <a href="https:&#x2F;&#x2F;www.cnet.com&#x2F;news&#x2F;q-a-kevin-mitnick-from-ham-operator-to-fugitive-to-consultant&#x2F;" rel="nofollow">https:&#x2F;&#x2F;www.cnet.com&#x2F;news&#x2F;q-a-kevin-mitnick-from-ham-operato...</a><p>&quot;I was cloning my cell phone to random subscribers and dialing into computers from the cell phone.&quot;

I had a Bearcat scanner that let you listen to the analog cellular bands. I think you had to use a harmonic frequency. This was probably 1992 or 93. I never heard anything interesting really.

In 1988 I bought a Uniden Bearcat 800XLT, specifically because it didn&#x27;t lock out cellular frequencies. Listened to lots of (one side of) phone calls.

Could somebody summarize the answer please? I&#x27;m trying to decide if it&#x27;s interesting enough to read, and the first 20 paragraphs suggest not.

That&#x27;s a fascinating story.<p>I&#x27;m curious though -- since the rule no longer has any practical relevance, is it still enforced?<p>Since it&#x27;s not particularly likely that Congress would ever get around to updating the law anytime soon... does the FCC still even care? If a hardware manufacturer openly tried to sell a receiver that could tune to those frequencies, would they still be stopped?

Seems we hugged the site to death :(<p>Here&#x27;s an archived version: <a href="https:&#x2F;&#x2F;web.archive.org&#x2F;web&#x2F;20201213003741&#x2F;https:&#x2F;&#x2F;computer.rip&#x2F;2020-11-28%20the%20verboten%20band.html" rel="nofollow">https:&#x2F;&#x2F;web.archive.org&#x2F;web&#x2F;20201213003741&#x2F;https:&#x2F;&#x2F;computer....</a><p>EDIT: Seems to be back up.

For ever new regulation that someone wants to enact, they should be forced to take at least 10 out.<p>100 years from now we might get down to a meaningful mix of regs. Right now the Code of Federal Regulations (CFR) is like the roach motel - regs check in but never check out :p

And yet you could dial TESTMODE on a StatTAC and listen to any analog channel.<p><a href="http:&#x2F;&#x2F;www.jax184.com&#x2F;projects&#x2F;StarTAC&#x2F;wireless&#x2F;testmode.html" rel="nofollow">http:&#x2F;&#x2F;www.jax184.com&#x2F;projects&#x2F;StarTAC&#x2F;wireless&#x2F;testmode.htm...</a>

Why are scanners so damn expensive? You’d think there would be Chinese copycats out there for $50

TL;DR: The Cellular Radiotelephone Service was allocated 824-849MHz and later 869-894MHz. That&#x27;s it.

I assume that frequency band is still reserved, even though it&#x27;s not used for anything anymore?

Great example of why every regulation should have an implicit sunset.

Is it just me or does the website raise a cipher mismatch error when trying to access it?