Zenith 8-5-463 black dial console. Didn't need; couldn't resist!

[Jeffhs]

The pushbuttons could well be station presets, as were (and still are) used on car radios. These presets were on one side of the radio dial in the Zenith sets; the buttons on the other side were for a tone control arrangement Zenith called, IIRC, the "Radiorgan". Some Zenith tabletop sets had the presets in a horizontal row just beneath the tuning dial. I seem to remember one such radio that did have the presets in this position.

BTW, I am fairly sure the model number of the Zenith radio being discussed here is 8-S-463, not 8-5-463.

[Jeffhs]

Originally Posted by dieseljeep

I made a mistake on my entry. They had one of those lousy repro cathedrals, either a Crosley or a Thomas. Some rediculous price, $12.00 or $15.00. I wouldn't pay 10% of that.

Lousy? Don't sell those replica sets short; some of them may be junk, but others might well be excellent performers. I have one, a replica of a 1934 cathedral radio, that works and sounds great. The only thing I can't figure out is why the FM tuning scale is so spread out on mine, as it uses a simple plastic tuning capacitor for AM and FM tuning, not a varactor or slug-tuned tuning system. Regardless, this radio works excellently, even in this semi-fringe area 40 miles away from most Cleveland FM stations. The wire FM antenna came disconnected from the radio somehow, but the set still works, bringing in every local FM station. The sound is great, owing to the 4-5" round speaker with a large magnet and a wood cabinet. I think I only paid $20 or so for this set at a discount store in my hometown. One of the speaker leads came loose from the PC board chassis, but I can fix that in five minutes flat; in fact, I am sure that is all that's standing between me and a really good sounding radio (for what it is).

I know my Zenith C-845, K-731 and Royal 3000-1 will run rings around it as far as sound quality goes, but as I said, for what it is, my little replica cathedral set doesn't sound half bad. It even gets a station my other radios don't get at all: a classical music station right next to (on the dial) a powerful country-western station about eight miles from me. The classical station is on 104.9, while the country station is 0.2 MHz down the dial at 104.7. This radio has full-time AFC, which one would think would pull the tuning toward the strong station, but on my little set it doesn't seem to work that way.

[dieseljeep]

Originally Posted by Jeffhs

Lousy? Don't sell those replica sets short; some of them may be junk, but others might well be excellent performers. I have one, a replica of a 1934 cathedral radio, that works and sounds great. The only thing I can't figure out is why the FM tuning scale is so spread out on mine, as it uses a simple plastic tuning capacitor for AM and FM tuning, not a varactor or slug-tuned tuning system. Regardless, this radio works excellently, even in this semi-fringe area 40 miles away from most Cleveland FM stations. The wire FM antenna came disconnected from the radio somehow, but the set still works, bringing in every local FM station. The sound is great, owing to the 4-5" round speaker with a large magnet and a wood cabinet. I think I only paid $20 or so for this set at a discount store in my hometown. One of the speaker leads came loose from the PC board chassis, but I can fix that in five minutes flat; in fact, I am sure that is all that's standing between me and a really good sounding radio (for what it is).

I know my Zenith C-845, K-731 and Royal 3000-1 will run rings around it as far as sound quality goes, but as I said, for what it is, my little replica cathedral set doesn't sound half bad. It even gets a station my other radios don't get at all: a classical music station right next to (on the dial) a powerful country-western station about eight miles from me. The classical station is on 104.9, while the country station is 0.2 MHz down the dial at 104.7. This radio has full-time AFC, which one would think would pull the tuning toward the strong station, but on my little set it doesn't seem to work that way.

The only replica set, that impressed me was the GE model, but they were rather pricey, but received and sounded great
The styling is genuine RCA-GE of the early to mid-40's. They might've been made at the same far-east plant as the Superadios.

[Tubejunke]

Well, since I was actually pulling in stations with little trouble I thought that I would yank the 6U5 "magic eye" which appeared to be dead. I've seen them all varieties of dim, but never completely dark.

The old thing is a little tough to pull, so I give it a good pull and the tube comes out and the socket falls apart in my hand. Nothing looks broken though. It wasn't hard to pull up a fair amount of material on the WWW concerning getting the thing wired back in correctly. This may be a good thing as the 1 Meg resistor I have read about revealed it's self and remains to be checked. At the same time it will help me in reconfiguring the socket. The two large pins are heater pins (1 & 6). The resistor jumps across pins 2 & 4 to B+. Pin 5 should be a wire that is a ground for the cathode and the only one left will be pin 3 for the grid. Not a problem.

The old Sylvania 140 proved that the tube was indeed dark as they come. So I got a short lesson in the fascinating world of the magic eye, which is deemed a cathode ray tube of sorts; a chance to check out the known problematic resistor, and weeded out another bad tube. I sort of hated tossing the old original script Zenith tube, but bad is just bad. On to yanking the chassis for a good cleaning a bit of wire replacement and likely power supply electrolytics. There is only minimal hum in the set and I can't tell yet if they run warm, but with what seems to be a delicate and slightly undersized power supply I don't want to take any chances. Later I may do the 1N4007 solid state rectifier job once I have worked other things out. Oh and there is a rubber or leather strap or band that controls the tuning. I have seen one online and it looks to me like an o ring with a hefty price. If that is all it is, I imagine I can size up something that will work for a few bucks.

[Electronic M]

Always keep the bases of fat pin tubes. You never know when you will need one.

[Captainclock]

Just so everyone knows it was actually someone on here that told me that the "GT" version of the 6X5 tube was actually a good tube to use in such circuits because they were less suseptible to shorting than the 6X5G was, and I actually have an old 1940s Philco Console that uses a 6X5GT as a rectifier and although I haven't had a chance to power it up yet because it had a mouse nest in it and the mice chewed through some of the wiring in the radio, I'm apted to believe that what that person said about the 6X5GT is true. By the way, from what I heard from this person is that there were two different grid arrangements for the 6X5 tube and the 6X5G tube and some of the early 6X5GTs used an "X" shaped grid (think of the later 6X4 or the 6CA4 which were the later replacements of the 6X5 tube), but then later on once tube manufacturers realized the fatal flaw of the 6X5 tube they redesigned the tube (the 6X5GT as the 6X5Gs were no longer being made at that time) so that it had inline grids instead of "X" Shaped Grids which made the tubes more reliable, at least until the 6X4 and the 6CA4 came out to replace the 6X5GT tube.

[Captainclock]

Originally Posted by TUD1

I once had a Philco 6X5GT short out and nearly destroyed the transformer. I caught it just in time.

Did that 6X5GT tube have the "X" shaped Grids or did it look like the one in the picture below? I'm asking because the 6X5s that had the "X" shaped grids were the ones that were more suseptible to dead shorting whereas the ones that had the grids that were inline like the one pictured below are less suseptible to dead shorts, that's what I was told anyways.

[Electronic M]

Originally Posted by Captainclock

Did that 6X5GT tube have the "X" shaped Grids or did it look like the one in the picture below? I'm asking because the 6X5s that had the "X" shaped grids were the ones that were more suseptible to dead shorting whereas the ones that had the grids that were inline like the one pictured below are less suseptible to dead shorts, that's what I was told anyways.

I've had the flat plate ones short on me in an EICO audio signal generator (both the one in it and it's replacement that tested good before installation, but not after). Never tried the X ones, but I'd assume they were better than the flat plates since the later 6X4 and 6AC4 used and those and were considered more reliable than the 6X5.

[dieseljeep]

Originally Posted by dieseljeep

The only replica set, that impressed me was the GE model, but they were rather pricey, but received and sounded great
The styling is genuine RCA-GE of the early to mid-40's. They might've been made at the same far-east plant as the Superadios.

I meant RCA-GE styling of the early to mid-30's.

[init4fun]

Originally Posted by Electronic M

I've had the flat plate ones short on me in an EICO audio signal generator (both the one in it and it's replacement that tested good before installation, but not after). Never tried the X ones, but I'd assume they were better than the flat plates since the later 6X4 and 6AC4 used and those and were considered more reliable than the 6X5.

Of course your correct here , the ones with the "X" shaped plates are the preferred ones to use if your going to use a 6X5 , as you rightly say the 6X4 and 6CA4 being the later model 7 and 9 pin replacement for what was the final improvement of the 6X5 design , the X shaped plates . In that transition they must have done something about improving the heater to cathode insulation , the way I always found the "flat plate" ones to be shorted . The 6Z4 , formerly known as 84 , was the first of these type of dual diodes and it was never pushed very hard with respect to it's H/K breakdown voltage since it was designed for the first vibrator power supply car radios (that replaced dynomotor powered ones in the early 1930s) and these were under 200 volt applications . The 6Z4/84 was the old large 6 pin base used before the Octals came to be , and when the Octals were introduced the 0Z4 was introduced along with them for car radio rectifier service , as we all know it's a Gas filled full wave rectifier that needed no heater at all . The trouble for the 6X5 started , in my opinion , when it was coupled to transformer supplies with 350 or more volts being pushed through a design that originally would have seen barely 200 .....

[Tubejunke]

You guys blow my mind with your incredible knowledge of tubes. Right down to a single tube and improvements after. I love tubes myself and often sit and thumb through my 50s Sylvania tube manual, but I don't know much about design changes and such. Love reading what you all write.

I haven't had time to progress much except for a bit of cosmetic cleaning on my Zenith. I was really surprised that night I had it pulling in stations as that crazy loctal tube reads pretty darned dead on two very good testers I own. Why in the world they would jam a loctal into the compliment is beyond me. Probably to save money. I wish someone could tell me the diameter of the tuning band, strap, or whatever it was that rots away on these. I think I can just use a common o ring to save a buck.