[mikethedruid]

I have begun the electronic restoration of my RCA 18T. It is filled with rubber covered wire. most of the insulation on it has become so brittle it crumbles and turns to dust, while on a few wires it has turned to goo. I have replaced the 4 section main filter condenser. Fortunately Antique Electronics Supply carried a PERFECT replacement. Perfect fit, exact same values, even the same terminal layout! I am replacing the paper condensers and all the rubber covered wire. My God, what a pain in the backside! Right now I am waiting on 12K, 10 watt resistors I ordered to replace one 12K 5watt resistor. I'll be happy when this one is done. Although the chassis is mostly wide open and easy to work on, in a few places, especially around some of the tube sockets, things are really crowded and replacing all the wiring is a tough job, watchmakers hands are required, and getting in there with my Weller gun takes real finesse. As you realize, a "pencil " type iron just doesn't provide the heat to do good soldering on these old sets. So that's what I have been doing the past few nights. I'll tell you more as things progress.

[Chas]

Route the replacement wire the same way as much as possible. The Nostalgia-Air schematic has the routing.

Do check the resistances of the IF's, they are wound with litz, sometimes strands break, resistance goes up and "Q" is lost. In that condition the IF will have a broad peak and poor coupling.
Seems RCA thought a lot about the IF system and suggest 'scope alignment, stagger tuning. Peak tuning will work fine as there is no "high fidelety" to AM any longer.

YMMV

Chas

[Paul Philco322]

Glad to hear it coming along, I do not have watchmakers hands, more like lineman's. The 18T has the brass thing under the Dial Glass, and the Dial Glass is very cool, love the numerals, How are the pushbuttons on yours.

How did you do with the rain from Florence? Saw it headed your way before making it up here.

Good luck with the set.

Paul

[mikethedruid]

I have looked at the schematic from Nostalgia Air, but I'm using a print out from my CD of Rider Manuals. It has the same diagram, which is really more a parts location diagram. It does not show most of the point to point wiring, which is where all that horrible rubber covered stuff is. I have been routing it as close as possible to how the original was, which involves some interesting weaving under components and other wires. Also, to make things easier and clearer, I scan the tube base diagrams from my old RCA Receiving Tube Manual, and then print them out. This I find useful to see what pin does what; it's a lot clearer than the schematic or even that layout diagram.

[mikethedruid]

Hi Paul, we didn't get too much rain from Florence, and just some breeze, no strong wind. The past 2 days we have gotten more rain from a regular weather system than we did from the remnants of Florence. Today I replaced the last of the paper type condensers, all except for one, which is buried under the band switch. I don't want to f**k things up by trying to replace it, so I'm going to leave well enough alone until I see how the radio works when I install the last resistor, which is a 5 watt 12K carbon resistor. I'm using a 10 watt ceramic covered wire wound resistor for that. It should be here on Saturday.

[Ron Ramirez]

[mikethedruid]

I finally finished my RCA 18T ! I REALLY HATE rubber covered wire. This was one of the worst radios I have worked on. Lots of crowded wiring around the tube sockets. RCA's documentation is not nearly as helpful as Philco's. I'm just glad it's over. It did turn out pretty well, if I do say so myself. It receives well on all 3 bands. All the push buttons work fine. I set them to AM stations I listen to this evening. This one was not fun, it was more like Purgatory.

[Image: https://66.media.tumblr.com/6e0bef924c08...o1_500.jpg]

[Brad Winder]

Lol! Good work!

My next project, after the 112 is finished, is to start on a 39-3116...and I'm going into it, assuming that there will be LOTS of crumbly rubber covered wire in it.

[EdHolland]

Nice work Mike. That radio is a beauty.

I think your experience was similar to mine with the RCA 110K2. I agree about the rubber wire, and the quality of RCA's documentation in comparison to what I have seen for Philco. But they are all worth it in the end

[Ron Ramirez]

RCA's documentation was among the best of any radio manufacturer until about 1937-38 when they started cutting back on info. The T7-5 (1936) I restored some months back and the 6T2 (1937) I'm currently working on have several pages of documentation. But, having Doug Houston's RCA Red Books, I can see that the later RCA models have considerably less documentation.

Good work on that 18T.

And Brad, you may be in for a surprise with your 39-3116. I have some Canadian Philcos made after 1938, and each one I have worked on has had mostly cloth-covered wiring - unlike their USA counterparts. You will run into some rubber-covered wiring. But I think you will find that most of it is cloth-covered.

[Paul Philco322]

Congratulations, looks very nice. How is the reception? Curious are they local AM stations or something we might pick up here. 

Enjoy the fruit of your hard labor.

Paul

[mikethedruid]

Thanks Brad, Ed, Ron, Paul. The AM stations on my buttons are WSM, 650kc, Nashville TN, home of the Grand Ole Opry; WLW, 700kc, Cincinnati OH; WSB, 750kc, Atlanta GA; WLS, 890kc, Chicago IL; WRVA, 1140kc, Richmond VA, and WLAC, 1510kc, Nashville TN. I can pick up WOR, 710kc, New York NY very clearly using the regular tuning. In the evening the whole AM band is alive with stations. I am using an outdoor antenna I made myself. I have high tension power lines for the TVA running over my pasture less than 300 feet from my house, so that posed a real problem. I solved it by making a vertically oriented antenna using PVC pipe and fittings, 18 gauge bell wire, and some brass screws and nuts. It stands about 20 feet tall from the top of the first T fitting, then 18 inches to the bottom T fitting, and a 6 inch stub at the bottom. The bell wire runs through the pipe, from a brass screw in an end plug fitting at the top, down and through a hole at the top of the 18 inch section, then it is wound around the outside of the pipe until the remainder of the 75 foot roll of bell wire was used up except for about 1 foot which went back into the pipe through a hole just above the bottom T fitting, and then fastened to another brass screw that serves as a terminal at the bottom of the 6" section poking out through another end cap fitting. I covered the whole external loading coil part with a layer of black PVC electrical tape. The whole thing mounts vertically to a 4 x 4 bolted to my back steps using 1 foot stubs glued into the T fittings, threaded end fittings on the stubs, and threaded metal mounting flanges that secure it to the 4 x 4. Works VERY well. It's surprising how little interference I get from those power lines using it. By the way, I live in Sneedville, in northeast Tennessee, about 5 miles from the Virginia border, so none of the stations I mentioned are really nearby.

[Paul Philco322]

I have got WLW, WSB, occasionally get WGN will try for WLS. So even in TN you are tuned in. 

Any luck on WBZ 1030 from Boston? 

Paul

[mikethedruid]

Hi Paul, Yes, I tried for WBZ 1030 tonight. It comes in understandable, but kind of weak, although not fading badly, about like WOR 710 from New York. I live on the south slope of Powell Mountain, so that does affect what I can receive somewhat. Stations from east and west and south do better than those from the north of me. Cincinnati and Chicago are closer to me than Boston, and Richmond is much closer than either of those two; so, although they are north of me, they come in stronger.

[Paul Philco322]

Nice to see you have some fun with it, skip can make things fun, DX is a nice hobby.

Paul