Got this 25LC20 set today in a deal I made with a friend and local collector. I had to give up my CTC-15, but I also got another set. Had to completely set it up. When I first plugged it in, the picture was horrible. Very dim and blurry. Had to rejuvenate the original tube, and now it's better, but not great.

I've been watching this set quite a bit. The tube is still waking up even after I rejuvenated it. It gets very bright now, I even had to turn the bias down a little. Focus is a little on the soft side though.

Got this 25LC20 set today in a deal I made with a friend and local collector. I had to give up my CTC-15, but I also got another set. Had to completely set it up. When I first plugged it in, the picture was horrible. Very dim and blurry. Had to rejuvenate the original tube, and now it's better, but not great.

Dave, you simply cannot expect a 52-year-old television to work anywhere nearly as well as a modern set; even if you replaced the CRT, the picture still wouldn't be as good as a modern HDTV. Those old sets will not work without modification on today's TV standards, so I don't know how you are getting a picture on yours unless you are using a DTV converter box or cable. I don't know how your cable service is set up in Birmingham but here where I live, in northeastern Ohio, the cable, as of the first of last month, is 100 percent digital, so a cable box is required to get any reception at all unless you use a streaming video system such as Roku, Google TV, et al. I have a Roku (Internet TV) box on my 19-inch Insignia flat screen and am getting beautiful pictures on every one of the seven TV stations (and their DTV subchannels) serving Cleveland.

However, I will say it again for emphasis, you cannot and will not get anything but snow on your 52-year-old Zenith roundie if you try to get local reception using just an antenna; again, I am baffled as to why you are getting anything on your set as it is unless, as I said, you are using a DTV converter box, satellite, or cable. If you have cable, your local cable system in Birmingham must not have made the full conversion yet to digital if you can hook up your cable directly to the TV and get a picture. However, the day will come when you will need a cable box on your TV to get anything at all. Spectrum (formerly Time Warner Cable) was the last cable system in the US to convert to full digital, so the cable in your area has probably been 100-percent digital for some time. The only other thing I can think of is there may still be one or several VHF NTSC television stations operating in your area.

Very nice find, as usual. I would be interested in seeing a picture of the screen after your setup procedure, showing something other than color bars. It sure does look like a winner to me. And it appears you got the legs as well? I think that’s what I’m seeing in the first photo, but not sure.

Very nice find, as usual. I would be interested in seeing a picture of the screen after your setup procedure, showing something other than color bars. It sure does look like a winner to me. And it appears you got the legs as well? I think that’s what I’m seeing in the first photo, but not sure.

Yes, I did get the legs and a spare NOS Triad flyback. This is the only picture I have at the moment of programming using my 2009 LG/Zenith DTV converter. (Way too cheap to pay for satellite/cable/etc.)

Uh... You do know that you have to actually work on the 52 year old tv if you actually want it to work correctly...

Uh... You do know that you have to actually work on the 52 year old tv if you actually want it to work correctly...

Uh... Well aware of that. I'm not new to this hobby. Plus, I don't have hundreds of dollars to spend on these things like some people here do. I have bigger problems, like keeping the refrigerator full and the lights on.

Yes, I did get the legs and a spare NOS Triad flyback. This is the only picture I have at the moment of programming using my 2009 LG/Zenith DTV converter. (Way too cheap to pay for satellite/cable/etc.)

Your Zenith roundie makes a darn good picture using that LG/Zenith DTV converter box, although I did notice the convergence is slightly off at the right edge of the screen. In the image your set is showing, the misconvergence seems worst with the word "Atlanta" on the weather radar map.

What are you using as an antenna with that DTV converter? You mentioned you don't have cable or satellite, so the only way your set would work at all would be with a DTV converter box, and I'm sure you are some distance from Birmingham's TV towers so you would probably need some sort of outdoor antenna. I wasn't aware these boxes were even available anymore, as inexpensive as many flat screen TVs are these days (I see some sets with 20-inch-plus screens advertised in my Sunday paper for under $200), although you said yours was a 2009 model so you've probably owned it since the beginning of the DTV conversion.

Your Zenith roundie makes a darn good picture using that LG/Zenith DTV converter box, although I did notice the convergence is slightly off at the right edge of the screen. In the image your set is showing, the misconvergence seems worst with the word "Atlanta" on the weather radar map.

What are you using as an antenna with that DTV converter? You mentioned you don't have cable or satellite, so the only way your set would work at all would be with a DTV converter box, and I'm sure you are some distance from Birmingham's TV towers so you would probably need some sort of outdoor antenna. I wasn't aware these boxes were even available anymore, as inexpensive as many flat screen TVs are these days (I see some sets with 20-inch-plus screens advertised in my Sunday paper for under $200), although you said yours was a 2009 model so you've probably owned it since the beginning of the DTV conversion.
Thanks, and yes, I'm aware of the convergence issue. I tried doing dynamic convergence using the coils on the convergence board, but they didn't do much of anything. I got it as good as I could and left it alone.

I got my Zenith converter box brand new in the box in January of this year at an estate sale. I'm using an Iron Butterfly antenna.

What is an Iron Butterfly antenna?

Phil Nelson
Phil's Old Radios
https://antiqueradio.org/index.html

What is an Iron Butterfly antenna?

Phil Nelson
Phil's Old Radios
https://antiqueradio.org/index.html

I think he means the classic UHF bowtie.

Yer bowtie ain't an Iron Butterfly till it has received at least the albums Heavy,
In-A-Gadda-Da-Vida, Ball, and Metamorphasis. :D

Thanks, and yes, I'm aware of the convergence issue. I tried doing dynamic convergence using the coils on the convergence board, but they didn't do much of anything. I got it as good as I could and left it alone.

I got my Zenith converter box brand new in the box in January of this year at an estate sale. I'm using an Iron Butterfly antenna.

If you are using just a simple UHF bowtie antenna, you must not be as far from Birmingham's TV towers as I had originally thought. You are only about 9.5-10 miles from the city of Birmingham itself (I looked up the city on City-Data.com yesterday), but it is possible you could be slightly further away from the TV station towers, as most TV stations have their towers located in high-elevation areas, often high-ground suburbs, so as to maximize their coverage areas. As an example, the TV stations serving my area near Cleveland are located in Parma, Ohio, a southwestern high-elevation suburb of the city, some 40 miles from where I live. There are some areas, however, such as New York and Chicago, in which the TV transmitters and antennas are actually located in the downtown areas of those cities; New York's stations are atop the city's Empire State Building (some having been relocated since the World Trade Center disaster in 2001), and most of Chicago's stations are atop that city's Sears Tower.

BTW, I didn't realize you had already reconverged your TV's CRT. It's been a while (45 years, to be exact) since the last time I had a TV with a round color tube, but I do recall that it isn't easy to converge them, especially in the corners of the screen. (I was trying to converge my set's tube by eye, without a pattern generator--believe me, I'll never do that again, as the results were far from even optimal.)

Most of the transmitters are on Red Mountain, which is about 10 miles away. The only channel I have issues picking up sometimes is WABM 58. On stormy days, it's hit or miss. I don't know where the tranmitter is for that station. I can pick up WBRC, WVTM, WTTW, WUOA, and WIAT without issues.

WABM is located on Golden Crest Drive just off of Beacon Parkway East... fairly close to many other tv transmitters. They have a construction permit to go to ch 20 for repacking. Decent power, but they do have a directional pattern with lower power going North.

https://transition.fcc.gov/fcc-bin/tvq?call=WABM&arn=&state=&city=&chan=0.0&cha2=69&serv=&type=&facid=&asrn=&list=0&ThisTab=Results+to+This+Page%2FTab&dist=&dlat2=&mlat2=&slat2=&NS=N&dlon2=&mlon2=&slon2=&EW=W&size=9

jr

This is what I MEANT to say...

WBMA-LP is located in Red Mt Park, but is much lower power... worse yet they have a construction permit to move to VHF ch 11.

https://transition.fcc.gov/fcc-bin/tvq?call=Wbma&arn=&state=&city=&chan=0.0&cha2=69&serv=&type=&facid=&asrn=&list=0&ThisTab=Results+to+This+Page%2FTab&dist=&dlat2=&mlat2=&slat2=&NS=N&dlon2=&mlon2=&slon2=&EW=W&size=9

jr

Examples of HDTV problems here. In Cleveland you only want to cover the city but not lake Erie ! So odds are most the power goes to the S & SW.

AM radio has great examples. WBZ Boston & IIRC WWL Nawlins were granted clear channels ( 50 Kw non directional) in the 30's but also were allowed to be directional so as not to waste power over oceans. Thats why WBZ could be heard in most the country winter nights.
Canada stations would build very highly directional systems south
of the cities & slam the city with power while protecting US stations.
Torontos CFTR 680 can not be heard in the Boston area. We get a local
plus Binghamton N.Y., Baltimore, Raleigh, N.C.
Only when the antenna has "problems" can we hear it & it crushes us
with a needle pinning signal.........

Your new Zenith dont look that bad. You should of see the junk people would watch in the olden days. Like I have said turn off the lights & turn everything down. That can make a HUGE difference !

73 Zeno:smoke:
LFOD !

I only have a string of Christmas lights hung from the ceiling, and two pretty dim LED's for additional background lighting. It's not very bright in here at all.

Most of the transmitters are on Red Mountain, which is about 10 miles away. The only channel I have issues picking up sometimes is WABM 58. On stormy days, it's hit or miss. I don't know where the tranmitter is for that station. I can pick up WBRC, WVTM, WTTW, WUOA, and WIAT without issues.

Dave,
You listed WTTW as one of the stations you can pickup. WTTW is the local PBS station in Chicago. Do they rebroadcast it down there ?
Ed

Dave,
You listed WTTW as one of the stations you can pickup. WTTW is the local PBS station in Chicago. Do they rebroadcast it down there ?
Ed

I'm not good with these call letters. Meant to say WTTO. Don't know why I said WTTW.

It's been a while (45 years, to be exact) since the last time I had a TV with a round color tube, but I do recall that it isn't easy to converge them, especially in the corners of the screen.
Huh? A roundie does not have "corners of the screen"...

.

Huh? A roundie does not have "corners of the screen"...

.

Those durned manufacturers. Always cutting corners...

LOL
No we know why they made roundies !

Huh? A roundie does not have "corners of the screen"...

.

That is what makes the corners hard to adjust! You can't see them so your converging blind. :D

I had a mathematician friend that once claimed that a circle could be thought of as a polygon with an infinite number of sides and therefore an infinite number of corners... but I thought that definition of a circle was pure BS. :)

jr

Interior to this thread, I can speak to one point:

Christmas lights will interfere with ATSC television reception.

Whether incandescent or LED is irrelevant. Stringing up any type of lamp containing 60 cycles AC, will thwart reception of digital TV to some degree.

FM Stereo will get noiser, and lose multiplex on a lesser tuner.

I've really screwed up now. I tried swapping the working chassis from the metal cabinet set into my remote set that I got a few months ago, and something happened, and now the thing looks like it's on a drug trip. Rolls horizontally, very unstable, no RF, no audio, etc.

I'd look at the synch separator/AGC stage (usually one tube sharing a cathode and a grid or two in Zeniths). No RF/sound and sync issues (presumably found by video injection, right?) sounds like a problem associated with that stage.

This is a really wild guess, but if you connected the tuner wires wrong perhaps you shorted the tuner AGC line and the issue fed back to something affecting both functions of the tube.

Horizontal roll (I assume you can get a slow roll in either direction, but it does not hold lock) could also be a bad H AFC diode package.

Did you try to connect the remote hardware when you did the chassis swap? Most non-remote sets lacked important aspects of the remote wiring and trying to adapt them to support that requires care and double checking of connections.

I set my Sencore VG91 to 45.75 MHz and injected it straight into the chassis, as I sometimes do for TV's that have lackluster tuners.

At first, I thought that I could have gotten the tuner wires mixed up, but I swapped them around and it made no difference.

I had to swap the volume and power controls by de and resoldering them onto the appropriate chassis. It "works", but I think there is a problem within the remote chassis, because it exhibited this same behavior before I swapped.

Examples of HDTV problems here. In Cleveland you only want to cover the city but not lake Erie ! So odds are most the power goes to the S & SW.



Zeno, I live very close to the south shore of Lake Erie (within a mile) and can hear most Cleveland AM and FM radio stations very well. However, I have problems receiving two DTV stations from Cleveland, both on VHF DTV channels. One of those is the CBS affiliate on RF channel 19, DTV channel 10. I remember when this station first signed on the air in 1985, long before DTV. It had a station identification that said, "We're 19. Stereo television for Cleveland . . . and . . . Lake Erie." This tells us this station, which had well over 3 megawatts of ERP before DTV, did cover a large part of the east lakeshore area; however, when it converted to digital, that signal weakened to 9.5 kW ERP, causing all sorts of reception problems east of Cleveland, including where I live. These reception problems on channel 19, and also the FOX affiliate on channel 8, were the reasons I eventually gave up on OTA television and installed a Roku box. Now I can get 8, 19 and every other Cleveland TV station as clearly as I used to get them when TV was all NTSC analog.

Huh? A roundie does not have "corners of the screen"...

.

I stand corrected. I meant to say I could not get decent convergence over every part of the round screen, although that may well have been because I was trying to converge the tube by eye instead of using a generator.

I set my Sencore VG91 to 45.75 MHz and injected it straight into the chassis, as I sometimes do for TV's that have lackluster tuners.

At first, I thought that I could have gotten the tuner wires mixed up, but I swapped them around and it made no difference.

I had to swap the volume and power controls by de and resoldering them onto the appropriate chassis. It "works", but I think there is a problem within the remote chassis, because it exhibited this same behavior before I swapped.

Until I saw the thumbnails attached to this post, I had never in my life seen such a weird CRT display on a color TV--and I worked on old cast-off TVs as a hobby for years when I lived in a house with a basement. I would not have thought it was possible to distort a color bar pattern that way, and I have no idea what was going on in your set to cause it. If you just swapped a couple of wires on the chassis, that should not have caused such a display. I am at a complete loss to explain why you are getting this, although I have never worked on a Zenith roundie color TV, or even Zenith rectangular sets. At this point I don't even want to guess what was causing this bizarre screen display.

... One of those is the CBS affiliate on RF channel 19, DTV channel 10...when it converted to digital, that signal weakened to 9.5 kW ERP, causing all sorts of reception problems east of Cleveland, including where I live.

Jeff, you have reversed the description of the situation. WOIO analog was on RF channel 19, with the requisite high power for analog UHF. They are now broadcasting in digital on VHF RF channel 10, with virtual channel number identifier 19. When they went to VHF, they got stuck with the low ERP due to the erroneous VHF planning factors that got baked into the system and did not take into account the level of ambient interference in the VHF band.

A proportionate increase in power of all VHF stations would solve the noise problem without causing added interference between stations, but this is impractical economically due to the number of transmitters that would have to be replaced and commissioned simultaneously. It also involves international treaties regarding interference levels across the Canadian and Mexican borders.

Hopefully this will be taken into better account with ATSC 3.0 broadcasting. It is a tough nut to crack because stations cannot arbitrarily increase power individually without considering interference to other stations that do not change at the same time.