25Hz TV's
 

I mentioned in another thread about the humongous power transformers some early Canadian TV's had. Toronto was 25 Hz up until about 1952. Hence the power transformers they employed were pretty big.

I spotted on the Toronto Craigslist a Toronto made Motorola set. The rear view of the set is interesting: there appears to be an outboard power transformer located at the bottom rear. You can make out some heavy cabling going from the transformer to the chassis.

I recall some older Canadian sets assembled from a US chassis which had transformers too big for the chassis. But I do not recall seeing the transformer mounted elsewhere.

http://toronto.en.craigslist.ca/tor/atq/2691715215.html

It might be a bit surprizing that central Arizona still had pockets of 25 cycle up into the 1970s, when the last of the Salt River hydro dams went to all-60 cycle. I remember in the town of Roosevelt (on the Roosevelt Dam for which the town was named), you could actually see the 25 cycle flicker of some incandescent lights. Up through the '40s and '50s, a lot of 25 cycle consumer stuff got scrapped along the way, and that's how i got ahold of the TV power transformers mentioned earlier, used as back-to-back modulation transformers. And i just used them 'cause they were handy. Nobody had said it "wouldn't work", so being a dumb kid, i went ahead and did it, and it worked. Often wondered if 60 cycle trannys would have worked as well in that application (in terms of avoiding core saturation with DC running thru the HV windings).
The owner of a TV shop in our town (Globe) was so impressed with the rig that he offered me a job which became the gateway to a lifelong avocation.
Some kinda interesting notes on the Salt River hydro system..
https://www.srpnet.com/gallery/trd/1971.aspx
http://www.usbr.gov/projects/Project...+River+Project

A 25 Hz motor wouldn't work on 60 Hz, but I see no reason why a 25 Hz
TV would not.

Many 25 Hz Canadian TVs would have an extra series choke.

An exception would be a 'universal' or brushed motor such as used in vacuum cleaners, SkilSaws, hand drills etc. It would run on 25 or 60 cycle, or equally well on DC (that was before solid state speed controls on power tools).
Correct. A 25 cycle power xfmr will run very happily on 60 but not vice-versa.
That's not at all surprizing.

Interesting thread. I was under the impression that 25-Hz TVs were a Canadian
only affair, but I understand some US areas also had 25-Hz into the TV era
(which obviously began earlier in the US).

Someone mentioned Toronto in Canada had 25-Hz until about 1952, that just
happens to be the year TV began in Canada. Areas in Quebec (Gaspesia) had
25 Hz until about 1963. I have seen pictures of fridges being fitted with
replacement compressors in that region (that was when a fridge was considered
a durable appliance...).

I have a few Stromberg-Carlson radios with holes stamped in the chassis for 25 cycle xfmrs. I believe some areas around greater Buffalo NY used 25 cps into the 50s or later. The 25 cps rail road power plants in Cos Cob CT were dismantled maybe 15 or so years ago. I remember seeing flatbed trailers with HUGE transformers on them headed to the scrap yard.

Metro-North converted the New Haven Line to 60hz in the early-mid 80's. Amtrak, Septa, and parts of NJ Transit are *still* 25hz to this day.

The parking lot at Lansdale is next to a substation. Those transformers don't hum, they rumble...

In our little hick town (Globe, AZ) there was another shop (Cody James Electronics) that specialized in converting TVs to 25 cycle for folks in Roosevelt. He would custom build a subchassis carrying the transformer, the 5U4, and filters and mount it just as shown in your example. Except the transformer was a lot bigger.
Our shop was LT Radio & TV Service. Darndest thing, Google Street View goes through that town, and the building is still there and virtually unchanged after 50 years. It's a baby goods and infant wear store now.

I used to live in Arizona and I never thought of Globe as a hick town! I do remember the copper mine!

And I never knew that Arizona used to have 25Hz power! This is very interesting information: I wonder besides canada and Arizona where else was 25Hz?

I wrote the guy selling the TV in Toronto and he sent some more pictures. The transformer mounting seems odd mounted on what appers to be a wood slab. However it does look original.

Note that the note refers to "Her Majesty". That means Elizabeth II was on the throne. My TV is a bit older and says "His Majesty" (George VI, her father). George VI died in February 1952 hence the set must have been made after then.

I wonder when the licence notice was dropped from Canadian TV's?

Here are the pictures so you can see for yourselves.

The first paragraph I find interesting.

The last sentance I find freaking hilarious! :lmao:

Yes, the town wouldn't exist without the copper mines. What years were you there? If it was anytime from '47 to '69, we mighta crossed paths. :wave: I guess Globe's only a hick town compared to major metro areas.
I dunno. But another interesting factoid about Arizona was the town of Young, a ranching community 'waaaay back in the hills beyond Roosevelt. It didn't receive Rural Electrification until 1965. As soon as the Juice was on, the people came to the nearest TV stores (including us) to buy color TVs and have deep-fringe antennas put up. We sold a lot of sets and put up a lot of antennas (with boosters) and Phoenix or Tucson stations would come in. Reception was still snowy, but at least the people had COLOR. :nutz:

If you mean a 25 Hz induction motor would not run *at the correct original speed* on 60Hz, you are right.

However a 25 Hz induction motor will definitely run on 60Hz although it will be 2.4 times faster.

You definitely cannot run a 60Hz induction motor on 25 Hz power because it doesn't have enough iron and windings and will over heat immediately.

Cliff