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-   -   Muntz TV Restore (http://www.videokarma.org/showthread.php?t=273846)

Dj3928 03-19-2021 08:27 PM

Muntz TV Restore
 
My latest YouTube video, restoring a Muntz tv
1959 MUNTZ TV Restoration Part 1 https://youtu.be/xUxp5Gt4VbU

Dj3928 04-02-2021 06:55 PM

Part 2 and final part of the Muntz TV Restore is now on YouTube
1959 MUNTZ TV Restoration Part 2 https://youtu.be/Qk6U80CNFBQ

decojoe67 04-03-2021 05:15 PM

I always liked those low-budget metal Muntz sets. The sedate, plain design has an appeal. It's a nice example too.

Jeffhs 04-04-2021 02:39 PM

Quote:

Originally Posted by decojoe67 (Post 3232688)
I always liked those low-budget metal Muntz sets. The sedate, plain design has an appeal. It's a nice example too.

Muntz TVs were good, but not great. I had neighbors in my home town who owned a Muntz console. Their set worked well enough, but it needed a good outdoor VHF antenna to make a decent picture (they had one, a so-called "lazy X" VHF conical antenna, on the chimney). My hometown was and still is a semi-fringe area for Cleveland TV, the transmitters being some 35 miles away (the area I live in today is worse, as it is almost 45 miles from the stations); this explains why my neighbors' Muntz set required an outdoor antenna to work anywhere near well. I don't know what type of RF amplifier tube Muntz used in its TVs of the '50s, but I wouldn't be surprised if it was a very low-gain tube; I'm sure they didn't use any kind of cascode RF tube such as 6BQ7, et al., as cheaply made as these sets were.

Muntz TVs were not designed for use in fringe or semi-fringe TV areas, but I'm not surprised. These TVs had bare-bones signal circuits and needed as much signal as they could get to make a decent picture. They might, and I stress the word might, work with an analog cable box today, but I doubt it very much. I wouldn't even try to use a Muntz TV with a modern digital cable box. That is, it might work, but since digital TV signals are so much weaker than their analog counterparts; as an example, the CBS television affiliate serving northeastern Ohio had a 3.7+ megawatt ERP analog transmitter from the time it signed on in 1985, but when they switched to digital, the signal dropped to--now catch this--9.7 kW (yes, kilowatts) ERP.

old_tv_nut 04-04-2021 04:09 PM

Not just the RF stage, but having only two IF stages made the Muntz sets unsuitable for fringe areas.

Regarding digital converter boxes, their analog RF output level is completely independent of input level. All set top boxes: cable, satellite, VCRs, D/A converters, game consoles, media players, have RF output levels within a range established by the FCC in the early 1970s, chosen to provide a noise-free picture without excessive interference to other equipment.

Per FCC part 15.115, with 75 ohm interface, this is 6 mV at peak sync for a master antenna system or cable system terminal device, and 3 mV for set top boxes. The audio carrier is limited to 1.34 mV or 0.67 mV, respectively.

https://www.govinfo.gov/content/pkg/...-sec15-115.pdf

dieseljeep 04-05-2021 10:04 AM

Quote:

Originally Posted by Jeffhs (Post 3232705)
Muntz TVs were good, but not great. I had neighbors in my home town who owned a Muntz console. Their set worked well enough, but it needed a good outdoor VHF antenna to make a decent picture (they had one, a so-called "lazy X" VHF conical antenna, on the chimney). My hometown was and still is a semi-fringe area for Cleveland TV, the transmitters being some 35 miles away (the area I live in today is worse, as it is almost 45 miles from the stations); this explains why my neighbors' Muntz set required an outdoor antenna to work anywhere near well. I don't know what type of RF amplifier tube Muntz used in its TVs of the '50s, but I wouldn't be surprised if it was a very low-gain tube; I'm sure they didn't use any kind of cascode RF tube such as 6BQ7, et al., as cheaply made as these sets were.

Muntz TVs were not designed for use in fringe or semi-fringe TV areas, but I'm not surprised. These TVs had bare-bones signal circuits and needed as much signal as they could get to make a decent picture. They might, and I stress the word might, work with an analog cable box today, but I doubt it very much. I wouldn't even try to use a Muntz TV with a modern digital cable box. That is, it might work, but since digital TV signals are so much weaker than their analog counterparts; as an example, the CBS television affiliate serving northeastern Ohio had a 3.7+ megawatt ERP analog transmitter from the time it signed on in 1985, but when they switched to digital, the signal dropped to--now catch this--9.7 kW (yes, kilowatts) ERP.

The only Muntz TV I have in my collection is a 1952 model 20" table model, 3 stage IF, 17 tube transformer powered chassis. It has a Standard Coil penthode tuner, 6AG5\6BC5 and 6J6 with no fine tuner. They ran the AGC wide open.
With a DTV convertor, it works reasonably well.


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