RCA 15K - Printable Version
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RCA 15K - Jayce - 07-04-2012 04:08 AM
About four or five years ago I aquired this radio from a friend of a friend after a failed attempt at getting a big Zenith console. Today I dragged it out after a year of sitting and got it going again and man, it still can kick a Zenith's butt! A rather nice radio that can shake a room on the right channel and with the controlls set up right! Also all the tubes but the eye tube in this thing are metal, which might be bad if you like the glow of tubes. I forgot how much I loved this set and it really shows RCA at thier best. Great tone and you can even get those electric highs from the 80's pop songs with the tone switch flipped clear over to Full Fidelity.
Anyways, now that I am done gushing, it does have one minor issue that it has had for years. The eye tube lights, but doesn't react. Is there a resistor in the eye tube socket that needs replaced or could it be something else?
RE: RCA 15K - Arran - 07-04-2012 04:27 AM
There is a 1,000,000 ohm resistor inside the base of the eye tube socket that is connected between the plate and the target, if it is burned out the tube will not react. Originally they used a 1/4 Watt resistor in this location but use the largest Wattage resistor that you can fit under that cap between the two tube pins, like a 1/2 Watt or better. There are also some other circuits that could cause it not to respond, the tube is driven by AVC voltage so a bad capacitor could also cause that condition. Also if some placed a 6U5 or 6G5 Magic Eye in place of a 6E5 the shadow will react somewhat but not close completely, if you place a 6E5 in place of a 6U5/6G5 the side of the shadow will overlap when closed, the grid bias voltages are different.
RE: RCA 15K - Jayce - 07-04-2012 05:32 AM
Hmm, ok. I think this radio still has the 6E5 tube in it if I recall right. Nice and strong yet. I'll check on that resistor.
RE: RCA 15K - Arran - 07-04-2012 06:22 AM
By the way, with regard to it kicking a brand Z set's butt I'm not surprised. RCA, much like Philco, put a lot of money into engineering, research, and development, on top of that they also benefited from the developments coming out of G.E's research department from time to time as well. RCA thought of themselves as the industry standard and backed it up with solid no nonsense products. Performance came first, styling came second, marketing came third.
Brand Z came up with flashy styling and marketing gimicks, chassis with metalic paint stuffed with lots of tubes, impressive looks, and marketing gimmicks, you can tell that their boss was a car salesman. Unfortunately he couldn't keep his nose out of the engineering department so they ended up with stupid things like undersized power transformers, extra rectifier tubes, using three tubes where RCA would have used one, etc., it was all about making the sale. Even in the 1000Z Stratosphere it was as though the front end for the short wave bands was an afterthought, it's actually quite embarassing given that they were supposed to be the flagship model. It wasn't that they couldn't make a decent set, the Transoceanics prove that, it's just that they had an autocratic layman, who didn't know one end of a soldering iron from another, micromanaging everything.
Philco on the other hand, was run by a former chemical engineer, RCA by a former radiotelegraph operator, neither were marketing men but understood the importance of producing the best performing product for the price.
RE: RCA 15K - Jayce - 07-04-2012 07:32 AM
Autocratic layman, seems to be who runs most corporations nowdays. One thing I do have to say I like about Brand Z is that they did seem to do better in the postwar years, considering how all radio designs went downhill once TV got going. Even that hit issues as everyone switched to circuit boards in the mid 50's and we have all heard the horror stories of those. Zenith stuck with a hand-wired, metal chassis in thier sets and at least the black and white sets seem fairly rugged and there is now worry of pulling the tube sockets out with the tubes! (A friend of mine just had this happen to a little set with the phelonic boards in it. Went to replace a tube and the board basically crumbled.)
RE: RCA 15K - Arran - 07-04-2012 08:18 AM
Quote:Autocratic layman, seems to be who runs most corporations nowdays. One thing I do have to say I like about Brand Z is that they did seem to do better in the postwar years, considering how all radio designs went downhill once TV got going. Even that hit issues as everyone switched to circuit boards in the mid 50's and we have all heard the horror stories of those. Zenith stuck with a hand-wired, metal chassis in thier sets and at least the black and white sets seem fairly rugged and there is now worry of pulling the tube sockets out with the tubes! (A friend of mine just had this happen to a little set with the phelonic boards in it. Went to replace a tube and the board basically crumbled.)
It's actually worse then that, most corporations seems to be run by comittees of MBA and accountant types, at least the old autocrats like Eugene MacDonald had a long term vision for the companies they ran and had an interest in keeping them successful, not simply an exit stratagy for themselves. I agree about the post war brand Zs, I don't know if it was the failures of the early 40s sets, the post war television boom, or the success of the Transoceanic sets but they seemed to have pulled their socks up during that time. They did do some stupid things with their early TVs though, like series string filaments with the plate voltages supplied by an autotransformer, or overdriving the flyback circuits by using two horizontal output tubes. Some of their radio and combo units also used an autotransformer, again more stupid corner cutting. I think they finally straightened things out after the "Commander" retired because the late 50s to early 80s brand Z TVs are some of the best TVs ever made.
RE: RCA 15K - Jayce - 07-04-2012 06:24 PM
The only issue I have had with postwar brand Z radios are the IFs. Of course, that seemed to be an issue with alot of radios, especially the 50's ones I have found. I hear you about the MBAs and such running companies nowadays. It's all short term gains and run away inflation as a result. Ah, for the days when stuff was made and companies made for the long term. No way we can rebuild today's crap like we can these old radios we love.
RE: RCA 15K - 7estatdef - 07-05-2012 03:10 AM
I had a set with the same problem the eye tube wouldn't light and that drove me crazy. It was a National NC-100X. A nice looking deco communication receiver from 1936 with P/P 6F6's and a xtal filter.
I had just finished up recapping it and checking all of the resistors except for the one on the eye toob. Couldn't find the darn thing and I had the shop manual for but I could find that resistor for anything. It wasn't listed on the pictorial and like Arran said it was inside the base of the 6E5 socket. I replaced it and was back in business.