Grebe

This is the finished unit with its speaker.

This is a Grebe Syncrophase MU-1 in for restoration. Below are some pictures of the disassembly process.

Get ready. .	Label everything.	Some liquid got into the hinge.	Use a box to support the chassis. Slip the case down and off.	Label everything

Removal of components and wires.	Label everything.	And label the printed picture too.	.
Denatured alcohol is used to clean the shellac covered cloth insulation.	A tooth brush with alcohol is used to scrub the bundle.	Brass brush the wire shiny.
Careful heating on low setting releases the wax.	B+ Bypass condenser	These caps are replaced. I would not want 90 or 135 volts on the old paper insulators.	C+ bypass condenser.	A little hot melt glue will adequately seal up these capacitors. The tin exteriors, not shown, are receiving a sprits of gloss black and a shellac top coat. I will save the original internals in case an owner would like an authentic non functional 1920's cap.
Time for the front panel mounted components.
Shot of the left side	Shot of the right. These will held reassembly	Capacitors labeled where no one will see when reassembled.	Yuk the dirt.	There is gold under the coal black dirt in the numbers! I will be making a trip to the hobby shop to find proper gold paint for the restoration of the engraved lettering!
You can't see it here but there is gold in the engraved Grebe logo too!	Repainted cap cans.	Those appear to be silver contacts. Shined up with a little brushing and Tarnex.	I will use the Tarnex on the bare wire. It makes it shiny silver again. Wire brushing only takes off the decades of crusted dirt.

Restoring front panel details.

Most of the Disassembly is complete. now for cleaning and restoring some finishes.

Clean and restore the bread board.

TEST 1 Mineral spirits does not dissolve the finish.	Cleaning with Mineral spirits.	OOoooh! Nice.	Test 2 Alcohol DOES dissolve this finish. It is Shellac.
After Steel wool and a bit of careful buffing with Alcohol.	I shut down the shop/shack and went to Lowes to pick up some 3# precut shellac. I will cut this to 2# for many thin coats. I would not want to overbuild the missing spots.	OOooh that's Nice!

Clean and consider what to do with the lid.

This is pretty badly chipped. I suspect reflowing will not work.	Dings and dents.		Not Shellac. That is dirt on the cloth. Most likely cigarette smoke residue.	Paint thinner did not dissolve the finish.
Mineral spirits a no go.	Yes, Lacquer it is. Those are tube heat burn marks. I thought the whole unit would be shellac as indicated from the bread board. But lacquer makes more sense for the 1920's vintage.
Reflowing or re-amalgamating the finish is out of the question. Too much missing finish. So stripping has been done.	Stain is deep and is in good condition. The hinge is rusted and pitted on one end. Zoom in on the high resolution (click on this thumb nail) to see the dents.
A water soaked cotton swab held on the dent then pressed with a hot soldering iron helps to pop out the dent.	Repeat this quite a few times to get the most expansion.	The steam will not work where there is missing material. Those spots will be filled before touch up stain and lacquer sealing. More later...04/02/2007

Oh boy! Time to reassemble some parts....

It has been a while since the shop saw my shadow. But I am back at it now that the weather has warmed a bit. Oh I was in now and again to touch up the gold lettering.

I will fill this table in as the radio goes back together.

Each piece has been individually shined up. Every rivet, every wiper bar and all exposed wire leads have been power buffed. Decades of dirt and oxidation is coming off. 0000 and 00 steel wool and a lot of Dremel cloth and fine wire wheels helped to get in the cracks.

These escutcheons are brass. No coatings were found. No tints. These have been buffed on a bench wheel with progressive polishing compounds. A light wax coat has been applied to keep the shine. 042507

This is when the labeling comes in handy. I took a lot of pictures to help reassemble the unit. Most of the pics are above. I can use the shop computer to blow up the pictures on this page to help locate connections and identifying tags. If all else fails there is also a schematic.

This radio is like an Erector Set of old.

Final Assembly.

This is the reassembled fully restored radio. After 60 hours of labor and a few parts this radio plays and sounds great.

Every nut, screw, bolt, washer, screw, latch, hinge, escutcheon, lamp socket, insulating fabric has been cleaned, polished and buffed to a shine. The cabinet received sanding sealer and many coats of clear and toning lacquer. The lacquer is still drying. The cabinet can be past wax polished after a few good weeks or months so all the coats dry hard.

The second RF Bi-nocular coil (center) started to arc from a ground rivet to the coil wire carrying B+ 90 volts. I removed a few turns of wire from where the rivet was contacting the wire, coated the wire with lacquer and rewound the wire back onto the form. I also snuggled the wires up and away from the grounded rivet creating an insulating air gap. Again lacquer was applied to the bottom three turns of the offending coil and form base. Once a day of drying has occurred once again B+ will be applied to the radio and tested.

Not bad for a radio manufactured in the 1920's.

Connecting the ABREIII

Time for the front panel mounted components.

Restoring front panel details.

Clean and restore the bread board.

Clean and consider what to do with the lid.

Oh boy! Time to reassemble some parts....

Final Assembly.