Can someone explain why on a 1955 Zenith - Videokarma.org TV - Video

radioguy13 · #1 08-17-2016, 12:12 AM

Can someone explain why on a 1955 Zenith the channel selector goes
2-4-5-7-9-11-13-3-6-8-10-12 ?? its not like you can change them to an order you would like since the channel selector knob is made like this ???
Kenny

***Eric H*** · #2 08-17-2016, 01:00 AM

Someone explained this once but I can't remember exactly why.
I think it has something to do with adjacent channels, in other words your area would more likely have a channel lineup in this order rather than 2-3-4-5 and so on.

zeno · #3 08-17-2016, 07:37 AM

Only thing I could guess is the knob has removable
numbers that got jumbled up. IIRC there is a kit on
e-bay now for UHF strips with a numbers set. Much
like for the 70's 12 & 18 channel selectors.
As far as the tuner goes if its a turret tuner you can
put the strips in any order you want.

73 Zeno

jr_tech · #4 08-17-2016, 09:57 AM

I have read that the strange numbering on the tuner was to make for quick tuning in most areas by skipping over adjacent channels that would not be assigned in a given area. Of course, cable changed that by using adjacent channels. For example the 2,4,5,7,9,11,13 group would be perfect for the Seattle area in the 50s, while 3,6,8,10,12 would be well suited further south in Portland. Remember, 4 and 5 are not considered adjacent channels because of the 4 mHz wide aircraft locater band situated between the two channels.

jr

BigDavesTV · #5 08-17-2016, 11:47 AM

I had always wondered why as well! In my teens, I had a '55 Zenith console that a teacher gave to me, and it's channel selector was odd-numbered like that as well. My set was VHF only, and the channels in my area then were 2,4,7,9.

radioguy13 · #6 08-17-2016, 10:15 PM

thanks for the reply as to changing the numbers on the knob well this one you cant do that the numbers are printed on the knob I posted a picture

radioguy13 · #7 08-17-2016, 10:17 PM

sorry here it is

Dave A · #8 08-17-2016, 11:47 PM

Philco did something cheaper with an 8 detent tuner using pairs that were locally tuned behind the selector by the installer for that market. PHL had 3, 6, 10 in the day (1950 or so). NY had 2, 4, 5, 7, 9, 11. I think the Philco possibles were 2, 3-4, 5, 6, 7-8, 9-10, 11-12, 13. Corrections gladly accepted. Zenith just did it with full tuning in sections.

Electronic M · #9 08-18-2016, 06:25 AM

Quote:

Originally Posted by Dave A

Philco did something cheaper with an 8 detent tuner using pairs that were locally tuned behind the selector by the installer for that market. PHL had 3, 6, 10 in the day (1950 or so). NY had 2, 4, 5, 7, 9, 11. I think the Philco possibles were 2, 3-4, 5, 6, 7-8, 9-10, 11-12, 13. Corrections gladly accepted. Zenith just did it with full tuning in sections.

Never seen a Philco like that, but the Motorola VT-71 did basically that...Though the numbers varied with the NUMEROUS production changes.

dieseljeep · #10 08-18-2016, 09:44 AM

Quote:

Originally Posted by radioguy13

Can someone explain why on a 1955 Zenith the channel selector goes
2-4-5-7-9-11-13-3-6-8-10-12 ?? its not like you can change them to an order you would like since the channel selector knob is made like this ???
Kenny

IIRC, Zenith did that from the very begining, with the Mayflower model. In order to adjust the fine tuning, the back had to be removed. The fine tuning was located in front of the tuner, as a spring return knob and shaft. You had to use a mirror to set the fine tuning. The Port-hole models were that way.

wa2ise · #11 08-18-2016, 11:36 AM

Back when I was about ten years old I was wondering why TV sets had empty channels: 3, 6, 8, 10 12. NYC had 2, 4, 5, 7, 9, 11, 13. Only reason I could think of was that the government (FCC) mandated it, for no other reason beyond that they could. I thought that the TV stations in NYC covered the entire country. My family never traveled. At the time my teachers in my grammar school were making us do pointless and stupid things, like memorizing poems. I figured that this would also be true in adult life...
I don't know how I would have made it thru life without knowing that Henry Hudson's ship was named the "Half Moon"...

jr_tech · #12 08-18-2016, 12:08 PM

Quote:

Originally Posted by Dave A

Philco did something cheaper with an 8 detent tuner using pairs that were locally tuned behind the selector by the installer for that market. PHL had 3, 6, 10 in the day (1950 or so). NY had 2, 4, 5, 7, 9, 11. I think the Philco possibles were 2, 3-4, 5, 6, 7-8, 9-10, 11-12, 13. Corrections gladly accepted. Zenith just did it with full tuning in sections.

My 12 inch (late 40s-early 50s) Philco has an 8 detent tuner that is marked 2, 3, 4, 5, 6 - 7, 8 - 9, 10, 12 - 13 . The 6 - 7 position makes no sense to me at all as it seems as if the gap between 6 and 7 (approx 86 mHz) would be too large to span with a simple slug adjustment.

Sorry 'bout the poor picture, but the dial is in poor condition.

dieseljeep · #13 08-18-2016, 01:12 PM

Quote:

Originally Posted by radioguy13

Can someone explain why on a 1955 Zenith the channel selector goes
2-4-5-7-9-11-13-3-6-8-10-12 ?? its not like you can change them to an order you would like since the channel selector knob is made like this ???
Kenny

Maybe Zenith did it for their Chicago buyers. Chicago had channels 2,5,7 and 9 and later 11. Some other locales had odd numbered channels, as stated previously.
Milwaukee had to change their first TV channel from channel 3 to 4, to avoid co-channel interference from channel 2, Green Bay and Chicago, depending on the weather.

Robert Grant · #14 08-18-2016, 11:14 PM

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Quote:

Originally Posted by radioguy13

Can someone explain why on a 1955 Zenith the channel selector goes
2-4-5-7-9-11-13-3-6-8-10-12 ?? its not like you can change them to an order you would like since the channel selector knob is made like this ???
Kenny

This sounds to me like someone at Zenith saw a picture of a British telly and thought it would be a good idea here.

As other posters here mentioned, first choice for more populated areas was not to assign channel 3, since doing so would condemn that area to having only two stations on the lowband. Likewise, assigning channel 8, 10 or 12 would limit a market to three or fewer channels on the highband.

Note that channel 2 got assigned to cities like NYC, LA, Chicago (later), San Francisco, Detroit, Houston, Boston and Pittsburgh, while channel 3 went to places like Eufaula, OK, Escanaba, MI, and Portales, NM. (Notable exceptions are for a reason - Philadelphia was too close to NYC and Cleveland was too close to Detroit, at least after the FCC realized that tropospheric refraction over Lake Erie would case too much interference).

The Detroit area was assigned 2-4-7, with Windsor across the river eventually getting 9. Toledo got 11 and 13 because and channel adjacent to Detroit's would be too close since the Toledo stations wanted their transmitters northeast of the city because TV antennas were aimed at Detroit.

Many British sets had channel 1 next to channel 9 on the dial. A single click to go from BBC to Rediffusion was not only convenient, it took a lot of mechanical wear off of the tuner.

dieseljeep · #15 08-19-2016, 10:44 AM

Quote:

Originally Posted by jr_tech

My 12 inch (late 40s-early 50s) Philco has an 8 detent tuner that is marked 2, 3, 4, 5, 6 - 7, 8 - 9, 10, 12 - 13 . The 6 - 7 position makes no sense to me at all as it seems as if the gap between 6 and 7 (approx 86 mHz) would be too large to span with a simple slug adjustment.

Sorry 'bout the poor picture, but the dial is in poor condition.

I've seen and worked on the sets, but never realized that channels 6 & 7 were one the same position, fully knowing that the entire FM band was located between those channels.
I can't see how the channel six strip could be tuned for channel seven. It's a possibility, that if channel seven is used, it was tuned on the channel eight strip and Philco furnished a corrected indicator disc.