View Full Version : What kind of TV is this?


Carmine
11-04-2007, 08:41 AM
...And what approximate year? Just curious. It's at an upcoming estate sale and I don't immediately recognize it. :scratch2:

http://www.estatesales.net/upload/275043.JPG

brokenbroken
11-04-2007, 08:53 AM
It sort of looks like a Magnavox, but hard to tell for sure. I'd probably guess mid 70's for the year since it looks like some I've seen from around that era.

Carmine
11-04-2007, 09:05 AM
Hey, how ya doing? Long time no post! Did you ever get that maggie combo working? I still have the Zenith you traded me... safe & sound, but more/less untouched except for a brief trial in '05.

I'm thinking it might be a magnavox from the early 80s too. It's so extra big, and I wonder if it's a combo, but doesn't seem to be, unless that whole lid opens! I wouldn't be opposed to using that extra speaker space to hide a DVD player, and a digital converter someday!

kx250rider
11-04-2007, 11:25 AM
I'd say mid 80s. It looks like that first split-board chassis NAP set after Magnavox went away from the T815-style modular chassis "Star System". I wouldn't be surprised if that's the very last Magnavox combo console.

Charles

Sandy G
11-04-2007, 11:30 AM
Looks like a dandy one Carmine- Hope you got a BIG space for it. Looks well kept, though, & I'd bet it has a good picture, or should w/a small amount of tinkering...

brokenbroken
11-04-2007, 11:59 AM
I'm doing pretty good, how are you? I haven't had time to really work on that Maggie much. I am using it for the radio though until I can find a crt for it.

Jeffhs
11-04-2007, 04:03 PM
I like big consoles, but unfortunately I have no room for them anymore since I moved to a small apartment almost eight years ago. However, my former home had a basement which, at one point, was half-full of old TVs, mostly portables but only three consoles, an Admiral (which looked like it might have had an AM/FM receiver and phono at one time, as big and long as it was), a Zenith 23" K2739 in a very nice walnut cabinet (wish I could have kept it, but I had to move about three years after restoring the set--so out with the trash it went; and after all the work I put into it, new tubes and the like...sheeesh), and a 21" Philco "Microgrid 390" with 6BQ7 cascode tuner, from the 1950s.

Carmine is probably right. The console TV under discussion here does look to me like a 1980s-vintage Magnavox, perhaps the successor to or a predecessor of the Star System sets with digital keypad channel selection. Can't tell if the set shown here has a remote or not. But the cabinet looks like a fine piece of furniture, which is why I think this set is from the days (unfortunately, however, probably near the end of the era) when Magnavox meant The Magnavox Company of Fort Wayne, Indiana, not Philips-Magnavox as it means today. I have yet to see a 1990s to present Philips-Magnavox TV in a wood console. The day Philips merged with Magnavox was the day the real-wood console era ended, although Zenith had a couple of consoles in the '90s, some of which are now appearing on ebay as their owners switch to flat panel HDTVs. However, those consoles were not real walnut, mahogany, etc.; rather, they were particle board covered with wood veneers and even--gasp!--photo-finish, the latter being a finishing method Zenith first used on the cabinets of its top-of-the-line radios in the 1930s. I think the day Zenith started using photo-finish and faux wood on its TV cabinets was the beginning of the end as far as the original Zenith Radio Corporation was concerned; today, faux wood cabinets, tomorrow (and to this day), TVs that don't last longer than a couple of years before something major goes wrong (such as the CRT shorting or worse). Zenith was once my very favorite brand of TV and home-entertainment equipment, but since they went to Korea and became Gold Star, I wouldn't touch their TVs with a 10-foot antenna. I still like Zenith's older radios and TVs (I have a small collection of their older radios, dating back to 1951), but as far as the new GS TVs are concerned, no way, no how, at least until or unless GS someday wises up and starts making TVs that last longer than the warranty period. But that isn't going to happen any time soon, if it happens at all--which I doubt.

peverett
11-04-2007, 10:02 PM
Jeffhs you mention 1950s Zenith radios. One problem that I (and is very common according to my radio collector friends) have with these is IF capacitor corrosion, causing leakover. Starting about 1950, Zenith and some others went to the small IF cans with built in silver plated capacitors. After 40+ years, the silver has tarnished causing the leakover. This results in static and loss of signal. Symptoms of this is a positive grid voltage on the IF amplifier tube and incorrect voltages on the detector stages. Have you seen this issue? One Zenith collector even published a fix for this. I personally have several 1950s Zenith radios and love the sound of the FM ones when they are working correctly.

Radios made before 1950 with the large IF cans and adjustible mica caps do not have this issue.

Jeffhs
11-05-2007, 04:28 AM
Jeffhs you mention 1950s Zenith radios. One problem that I (and is very common according to my radio collector friends) have with these is IF capacitor corrosion, causing leakover. Starting about 1950, Zenith and some others went to the small IF cans with built in silver plated capacitors. After 40+ years, the silver has tarnished causing the leakover. This results in static and loss of signal. Symptoms of this is a positive grid voltage on the IF amplifier tube and incorrect voltages on the detector stages. Have you seen this issue? One Zenith collector even published a fix for this. I personally have several 1950s Zenith radios and love the sound of the FM ones when they are working correctly.

Radios made before 1950 with the large IF cans and adjustible mica caps do not have this issue.

No, I was not aware of that particular problem (leakover, caused by tarnished silver-plated caps) with Zenith radios of the 1950s, although, to be perfectly honest with you, I've been away from the service aspect of electronics since I gave up my workshop in my former home almost eight years ago. Perhaps someone a bit more familiar with these radios who still has a workshop and/or access to test gear can give you a better answer to your question. (The only test gear I have here in my apartment is a DVM.)

I agree with you, however, as to the sound of the old Zenith radios. I have two Zenith AM/FM sets, a K731 and a C845, which, even after 40+ years, still sound absolutely great on both bands, but the 845 has somewhat better sound than the 731 due to the 845's 8-inch speaker and a true tone control that does more than simply cut the high frequencies. The C845 is also hotter than a firecracker when it comes to RF sensitivity, as it has a 6BJ6 RF amplifier that operates on both AM and FM--mine will consistently bring in stations from 80 miles away, just using its built-in antenna; I hate to think what a mess my radio dial would be if I had an outdoor antenna on this thing, as I'd have FM stations coming in like gangbusters from perhaps 100 miles away. As it is with the built-in antenna, the set gets all the Cleveland stations and, when the FM band opens up in the summer, I get stations from Detroit, Toledo, Ohio, and southwestern Ontario, Canada as well. But that doesn't surprise me. I live within a mile of the south shore of Lake Erie, so I consistently receive Detroit/Toledo/SW Ontario stations on all my radios--even my 1980-vintage Zenith R70 transistor portable. That doesn't surprise me either. That little portable has four IF stages and an RF stage on FM and two ceramic filters, one for AM, the other for FM. The R-70 has a circuit board (Zenith apparently had broken with tradition by 1980, as this was the year it started building its radios and even TVs [!] on PC boards rather than steel chassis and handwiring), but it still works and sounds excellent, even with a 4-inch speaker.

The R-70 was, I'm sorry to say, one of the last really good transistor portables made under the Zenith brand before Zenith got out of the radio business, but by the eighties even these radios, not to mention Zenith televisions, were not being manufactured in this country anymore. There is a molded-in notice on the back of my R-70 that states this fact all too clearly: "Manufactured in Korea to the standards and specifications of Zenith Radio Corp., Chicago, U.S.A." My Zenith H480W clock radio (AM/FM/FM-stereo) bears the same notice, only the country of origin is Taiwan. I had a Zenith stereo system in the '80s that was also manufactured in Korea to Zenith's specs and standards (again, there was a notice to that effect on the back cover).

Believe it or not, both radios (C-845 and K731) even have their original filter caps and selenium rectifiers. I can't believe that seleniums can last that long without shorting (both radios were made in the 1960s). I don't think much about it, but a radio with 47-year-old seleniums is on borrowed time; there is no telling when the other shoe will drop, meaning the rectifier shorts and gives off that telltale rotten eggs smell. When I was a kid, we had a Crosley Super V 21" TV, 1950s vintage, with selenium rectifiers; the rectifiers were still good when we finally got rid of the set in the '70s. I mention all this because I remember reading somewhere (probably here on AK in the television forums) that seleniums will short on their own after a few years, for no apparent reason.

Again, I'm sorry I couldn't have been of more help with your Zenith radio problem, but as I said, I've been away from servicing too long. I could measure voltages on tubes with my DVM (as long as the voltages don't exceed 600 volts, the limit of the meter--my DVM is a cheap foreign import under the name of Velleman) and so on, I can read a schematic as well, but I'm really in no position to do in-depth service work on electronics anymore. As I mentioned earlier, perhaps someone better equipped than I may be able to advise you in detail as to the leakover problem in early (1950s) Zenith radios.

What exactly is "leakover", anyway? I'm guessing it has something to do with signal loss, but that's all it is--a guess.

I learn something new every time I read the posts in these forums (I am a member of AK and am always and forever lurking in the forums, occasionally posting if I feel I can be of assistance or need help with a sticky problem of my own), and tonight, when I read your post, was no exception.

Chad Hauris
11-05-2007, 10:58 AM
The leakage is of DC from the plate circuit side of the first stage to the grid circuit side of the next stage. There is a mica wafer in the bottom of the can and it makes up a capacitor, along with some contacts on the top and bottom of the mica. The mica wafer has plate circuit contacts on one end and grid circuit contacts on the other.

I have fixed the problem by removing the mica and trimming and insulating the capacitor contacts to avoid shorts...Then I use a 22 picofarad cap for FM circuits and a 88 to 100 pf cap on AM circuits, which is connected externally across the contacts at the bottom. Another good suggestion is to cut the mica sheet to break the leakage path but I have not tried it personally.

I have seen this problem in all kinds of 1950's era radios...Wards Airline, RCA, not just Zenith.

peverett
11-05-2007, 11:46 AM
Chad Harris describes the problem perfectly. The fix that I have seen on the internet is also what he describes. I personally have tried cleaning the capacitors with varying results. I did cut the mica sheets on a GE that used an IF can of a special construction. On this particular radio, it worked.

Also as Chad mentioned, the problem was not specifically limited to Zenith. It seems to be in a lot of the radios using the inductivly tuned small IF cans that were used, starting in the 1950s.

bgadow
11-05-2007, 01:07 PM
Set looks a lot like a GTE Philco combo I saw once.

radiotvnut
11-05-2007, 02:10 PM
Come to think of it, that set does look like a GTE Philco or Sylvania (same thing) from the late '70's. I had a similar one years ago with a shot delta gun CRT. The chassis was a single PC board built around a metal frame. The tuner was a single knob varactor type.

Randy Bassham
11-05-2007, 04:01 PM
That set is about the last of the Magnavox theater sets. It's a much cheapened version, the TV is actually entirely separate from the stereo and has its own 4X6 speaker under the tuner assembly. That model in the picture has the varacter tuner with manual presets and gave quite a bit of problem with contacts, the earlier versions of this type set had separate manual VHF and UHF tuners, there was no remote option. The cabinet is completely made of pressed wood with a faux wood painted finish. Notice that the lids for the tuner and turntable open up from the front not the earlier great combos Magnavox made that had the sliding lids on top. Most of the sets that I ran across had the T995 chassis but could very easily have had the T815 in the last runs (it's been a long time ago). They were decent sets just nowhere near the quality of Magnavox of earlier days and lacked a lot of the features. I delivered sets like this in 1978 and 1979 before I quit working for the Magnavox dealer and it was not long after the Philips buyout when we started seeing the quality of the cabinetry going down, then I think just before I left we started seeing the influence of Philips on the circuitry.

radiotvnut
11-05-2007, 08:09 PM
I just found one like it on epay (item #170164270058) with several pictures. It even has an el cheapo BSR record changer in it. These are certainly not the quality of the '60's Magnavox combo units.