Canada’s CHU time station to close

[IM42A]

The handset used 49 MHz channels. Later mobile phones used 46 and 49 MHz channels. Peter Cavanaugh had a chapter online or in his book "Local DJ" about listening into executives discussing risqué topics.

I had a GE radio (and still do, it's here somewhere, I just don't know where it is) that could pick up these frequencies, and I could pick up mobile phone conversations seemingly from all over our neighborhood. One night a woman was using particularly florid language and dropped an f-bomb or two. That was a hoot! I don't know who she was, but she was cussing like a sailor.

 

[Mediafrog+]

Very early mobile phones used the 1600-1700 kHz band

Those would have been cordless phones connected to landline outlets, not what we would think of as mobile phones of the time which had a wide service range.

Base station frequencies for the early cordless phones were between 1665 and 1770 kHz, while the handsets were around 49 MHz. The base stations were later moved to the 46 MHz range.

More info: https://www.hfunderground.com/wiki/index.php/Cordless_telephone

Not sure if it was cell phones using TV Channels 70-83, or some earlier mobile phones on other bands.

The first generation of AMPS cellular service was on frequencies between 806 and 890 MHz, what had previously been allocated to TV channels 70-83.

 

[Josh Owens]

As some of us in the Eastern part of the US remember, WWV used to broadcast from Beltsville, Maryland. The 5 MHz signal was usually very strong in Michigan, and I'm sure parts East. When they moved to Fort Collins, CO, the signals were much weaker. I wonder if WWV should take over the 3330 kHz and 7850 kHz frequencies. 3330 in particular blasts in at shorter distances, and transmit from some place in Upstate New York perhaps, and would serve the East Coast and Great Lakes Region better. Strange thing about WWV though, is that 25000 kHz often blasts into the Great Lakes Region much better than any other frequency, and often signals VHF imminent band openings including Sporadic E.

I may have mentioned this before, can't remember. I got my first short wave radio for Christmas of '87, at the age of ten. I discovered WWV the following New Years Eve and listened to them for the looooongest time, just captivated! )

 

[gr8oldies]

That’s what those transmissions were for…long distance phone calls via shortwave radio. Commonplace 50+ years ago. The ”circuit adjustment purposes” announcements were just audio placeholders.

Ship to shore phone calls on shortwave were also quite abundant in that era. No privacy for your call, but anyone with half a brain knew that and avoided talking about anything private or sensitive. Made for interesting listening on the maritime bands back in the day.

Make sure to not give details on where you stashed the drugs

 

[gar hi]

Back in the early 70's, my brother had a portable multi band radio that could pick car phone conversations too that were within a few miles.

It was usually someone in a car talking to someone with a land line.

I think it may have been on the VHF band.

I was surprised they were there for anyone to hear with a receiver because some of those conversations were better than any soap opera. 😁

 

[KeithE4]

Back in the early 70's, my brother had a portable multi band radio that could pick car phone conversations too that were within a few miles.

It was usually someone in a car talking to someone with a land line.

I think it may have been on the VHF band.

I was surprised they were there for anyone to hear with a receiver because some of those conversations were better than any soap opera. 😁

Mobile phone services were on parts of the 30-50, 150-174, and 450-470 MHz bands in the 1950s-1970s. They used the same equipment that were used by other services in that era.

They were later bought by hams on the used market, and were the first FM transceivers on their bands prior to 1970.

 

[cc333]

Are these radio phones still usable (and legal with the proper licensing) without the old analog landline phone system to talk to?

c

 

[KeithE4]

Are these radio phones still usable (and legal with the proper licensing) without the old analog landline phone system to talk to?

c

Given that the technology is decades-obsolete, I seriously doubt it. Maybe some hams will still attempt to convert them to 6 or 2 meters or 440 MHz, but that era is long gone.

 

[KyleSmith1988]

Similar to CHU, NRC Canada still has the time signal updates accessible on the phone (in English & French). I guess its ok to post the numbers here:

(613) 745-1576 - NRC Canada Time (English) 🇨🇦
(613) 745-9426 - NRC Canada Time (French) 🇨🇦

Also, the US Version of time signal broadcast (WWV & WWVH) is accessible on these phone numbers as well:

(303) 499-7111 - WWV (Colorado) 🇺🇸
(808) 335-4363 - WWVH (Hawaii) 🇺🇸

 

[yeoldeschool]

They were later bought by hams on the used market, and were the first FM transceivers on their bands prior to 1970.

I never knew that. I thought most early 6, 2, and 440 gear was converted commercial two-way surplus, the sort with handheld microphones with the big ominous Ms on them.

Well, landlines weren't especially private either, but they were more resistant to casual listening by outside parties because one had to physically tap into them, which the casual eavesdropper would not even want to try.

When CALEA forced government backdoors into all our PSTN switches in 1994, experts said they would become targets for hackers. A couple of years ago, those people were vindicated when, to the government's humiliation, the Salt Typhoon scandal broke, revealing that foreign actors were crawling in and out of those backdoors like baskets of snakes, listening in on all the calls they wanted of pretty much anyone they desired. The public-facing messaging was that the backdoors had only been breached recently. To many, that was government speak for their regular abuse having only been recently discovered.

Phreakers knew about and were getting into phone company REMOBS and even operator trunks decades before CALEA.

Are these radio phones still usable (and legal with the proper licensing) without the old analog landline phone system

Technically yes. Even though MTS utilized analog radio transmissions, it didn't depend on the PSTN itself remaining analog. The PSTN began switching over to digital (save for our last mile copper loops) in the 1970s, and MTS happily continued chugging along in spite of that -- at least until AMPS dislodged it in the 1980s.

As for whether MTS could still be offered as a service now, Wikipedia's MTS article surprisingly suggests it still exists in some very rural areas. But in most locales resembling human civilization, the frequencies formerly allocated to it (see KeithE4's post or the Wikipedia article) were evidently gobbled up long ago by the old school one-way pager companies. Which would put the kibosh on ever resurrecting legacy MTS gear in most areas without doing hardware modifications.

And even if someone wanted to go that far (or make new hardware), there would be no customers. MTS was only capable of supporting up to 33 simultaneous calls in each service area, and since it relied on elevated transmitter towers, each of its service areas was widescale. (Intended customers were mostly corporate and executives.) Here's a campy late-1940s AT&T film detailing its introduction and showing some of the original automobile units involved:

Interestingly, one-way pager service still exists. Doctors and certain other professionals still love having it because pager transmitters run high wattage and penetrate deep into buildings, including underground concrete basements. Other people who want to be reachable without modern cellular carriers data mining their exact travels also like pairing them with dumb phones. (The dumb phone stays in a faraday pouch so it can't amass GPS coordinates over time, and it gets pulled out only when the one-way pager goes off, indicating someone wants to talk.)

 

[IM42A]

Just out of curiosity, what bands did the mobile phones in the 1970s use? My cousin was in real estate and had a phone in his car (Lexington KY).

 

[kevtronics]

Just out of curiosity, what bands did the mobile phones in the 1970s use? My cousin was in real estate and had a phone in his car (Lexington KY).

Improved Mobile Telephone Service - Wikipedia

en.wikipedia.org

The original Bell System US and Canadian mobile telephone system includes three frequency bands, VHF Low (35-44 MHz, 9 channels), VHF High (152-158 MHz, 11 channels in the U.S., 13 channels in Canada), and UHF (454-460 MHz, 12 channels).

 

[KeithE4]

I never knew that. I thought most early 6, 2, and 440 gear was converted commercial two-way surplus, the sort with handheld microphones with the big ominous Ms on them.

Same radios, different handsets/control heads. The radios were mostly made by Motorola and GE. The control head was mounted in the car, with the radio itself in the trunk.