Restoring the RCA 86K7 - Day 1

If your looking for the Schematic and Alignment Data for this model, please follow the link on the menubar to the left.

My summer project this year is rebuilding an RCA model 86K7, released around 1936/37 and was one of seven models released for this time period.

1. 86E Tabletop
2. 86K Console
3. 86K7 Console
4. 86T Tabletop
5. 86T1 Tabletop
6. 87K Console
7. 87T Tabletop






Physical Description

Every now and then I'll try entering a vague description into Google to see what a model number is or what it's called. I sympathize with those who do the same, so for our Googlers out there who have found a radio at a swap-meet or flea market and are wondering if this may be it, here ya go.

The RCA 86K7 is a 6 tube console radio with a two "hand" clock type dial face (or clockwork dial as I call it - see photo below) which seems to be the main distinguishing feature of this radio. The 86K and 87K console models also use this twin indicator design.



Getting Started

Let's begin by making a cursory inspection of the radio and a preliminary checklist of the basic things we want to do.

PROBLEMS:

(aside from the obvious that is)

1. The Tuner slips
2. The collar for the Band Switch flag is broken off.
3. The bakelite knob for the tuner is broken and tension spring is missing.
4. Grill Cloth is "Radio Shack Special"
5. Cabinet need a little work

CHECKLIST:
(in no particular order)

1. Replace tuning drive belt
2. Test tubes and replace bad ones
3. RECAP!
4. Replace or repair band selector flag bracket
5. Replace Grill Cloth
   

This is my first major rebuild. Please be charitable in your opinions, I know I'm going to screw-up or overlook something.







This is our 86K7 as it sits now. The cabinet needs a bit of work but it looks like it has been refinished once already.

You can click on any of the photos to bring up a larger version of that photo.



A quick look under the hood and we see that all the tubes are gone but not to worry they're in a brown paper sack that was in the cabinet with the radio.

A good going over with a soft brush is plan number one, whiffing away years of dust and the remains of at least one unfortunate spider.







As we examine the underside to make a list of what capacitors we are going to need to reacap it, I decide to take a look at that slipping tuning belt. The tuners drive belt is accessed by slipping off a number of small push clips to remove the ivory "Sunburst" face. It turns out I'm missing three of these and I don't know if I can replace them.

The hands to the clockwork tuner slip on and off just like those on a real clock.






Now this is one of those things that if your wrote it into a book or Hollywood script no-one would ever believe it, but as luck would have it I just happened to have another tuner drive belt in my toolbox, slightly smaller and a MUCH better fit than the one that came with it (I hesitate to call it "original", but it may have been).







Okay, tuning belt fixed.

To overcome the broken bakelite knob, it was just a minor chunk missing from the shaft. The real problem is that missing spring. A bit of electrical tape doubled over provides a quick temporary fix for this. Works fine.

As for that broken band switch flag, I spoke to a friend online who works with a machinist who can replicate that bracket. I hope to hear from him soon. :)


(EEK fuzzy photo!!)


Okay I know we haven't done much, but the moon is high and it is getting late so enough for today, let's stick the radio back in it's cabinet and say good night.