Posts: 42
Threads: 7
Joined: Apr 2009
I picked up one of these for twelve bucks. It's a tad pricey for the condition but it gave me something to work on. I need to find two small knobs for the clock alarm and alarm set knob that look very similar to wire nuts. The speaker need some repair as well and this looks like a fine specimen to try my first speaker repair on. The electronic restoration - there's a capacitor that has burst into two pieces - looks straight forward but cramped for space. I've got the clock cleaned and the rotor working again but I'm a little unsure about how the radio is turned on by the alarm set. I can see how the alarm buzzer works. There's a notch in a disk that allows a metal strip to drop against post thats connected to the rotor's electromagnet. This produces an annoying 60Hz metallic buzz. How does the radio alarm work? There's a three position switch for the radio. One position is ON and it closes the contacts to turn the radio on manually. The others allow the contacts to open and I can't see how the alarm mechanism could turn on the radio. I've got a feeling someone has robbed the radio of parts.
Has anyone worked on one of these?
Posts: 269
Threads: 12
Joined: Nov 2005
City: Nashville, TN
Hi,
The Nostalgiaair pages only show changes and not the radio's actual diagram. Do you need that? I suspect you will.
I also have the Riders page showing the clock service info. I will send off the scans of this set to your email.
By the way, I don't think this radio has a 'wake to music' function, but I might be wrong. It seems that is is just an alarm. UNless after you kill the alarm the radio power switch is ON.
I have not fooled with many clocks except to lube os clean the contacts for the power. That usually need cleaning if the contacts are exposed.
EDIT>>> Scans sent to your email address.
Will get these scans to you ASAP.
Good luck,
Gary.
Posts: 42
Threads: 7
Joined: Apr 2009
Status Update:
I dismantled the clock, cleaned off the old grease and oil and reassembled it. The rotor was a bit to noisy for me. I can only think of little gears grinding and rattling away to keep time. I used an abrasive circular cutter with a Dremel tool to slice a small gap on the top of the rotor so I could inject a teaspoon of Marvel Mystery Oil. I sealed the rotor by hammering a small piece of lead (I could have used solder)into the gap. After smoothing over with a fine hobby file, I finished it off with a tiny duct tape patch. The clock runs silent except for a small 60 cycle hum I can hear with my ear on the case. No more rattles or grinding sounds.
The radio does have a music alarm. The radio comes on 7 to 10 minutes before the alarm buzzes. I had to fabricate a C-shaped missing part from 0.012" brass to make it work. This part is attached to one end of a lever arm that rides on a slotted disk that turns with the hour hand. The disk hold the lever up which in turn keeps the contact for the radio open. When the arm drops in the slot, the contact can close. A few minutes later, the buzzer is triggered much the same way.
The radio is an AC/DC type, which sort of scares me. I replaced all of the paper capacitors and the three electrolytics. I also need a new 2200 ohm power resistor and a replacement for the 22pF antenna cap that's shorted. The audio section of the radio works but I think the diode may be bad. All of the voltage reading from the circuit common are off. They should be around zero but they are 30 to 40 volt range. I've also tried applying a signal at the grid and the volume next to nothing. I can't decide if I should simply get a new diode (12SQ7) do more testing after my missing and bad components are replaced.
Dang thing with a floating ground is tricky to work with but I haven't been shocked yet. That hot chassis has me worried.
The Telechron clock radio 8H59 Musalarm is idential. A schematic and service notes for the clock and radio are available at Nostalgia Air. Interesting that the instructions on how to rewire the 2200 ohm filter resistor when using the radio is fitted with a center tapped transformer. I've stayed with the notes for the GE model that Gary gave me.
Posts: 42
Threads: 7
Joined: Apr 2009
This restoration has been a challenge. The radio was dead. All of the old paper caps and the electrolytic was replaced. Most of the resistors were good but the filter resistor was short lived. It turns out that the AF and IF trim capacitors were shorted to the chassis. The original was 2200 ohms and I replaced it with a 1700 ohm 10 watt resistor so I could have enough time to measure the voltages. The B+ and chassis were identical and the I had a a 125 volt drop across the filter. I tracked down the short by checking continuity at a B+ node and followed the branches. I'm somewhat surprised that the trimmers were the problem because there was no short at first.
The trimmers seem simple. A screw controls the distance between two plates which in turn determines the capacitance. I can open and close the distance between the two plates and the capacitance doesn't change as measured by my multimeter. I'm not sure if they are good or bad since I'm not sure if a multimeter can make that measurement. I need to do an alignment so a quick check would come in handy and save a bunch of time. Getting the tuning set will be odd. This set has permeability tuners - little coils with an iron core that's pulled in or out of the AF and IF coils. Fortunately, I have a good reference book and the alignment instructions from the manufacturer.
Antenna: The schematic shows no loop and none came with the radio. Reception is weak unless I touch the antenna and that's not good thing to do with this radio. I would think there has to be a loop that was removed. Otherwise, people would be getting electrocuted. If anyone has one similar to the GE50/Musialarm and know about the antenna, you help would be greatly appreciated.
Posts: 7,212
Threads: 266
Joined: Dec 2009
City: Roslyn Pa
Well first off your little GE 50 doesn't have an IF adjustment as it isn't a superhet. It's a TRF set with one RF amp a Detector and two audio stages. Your right that it never had a loop. It had a small roll of wire that was to be use as a antenna. I had one years ago. Cute but not a very good performer at all.
Terry
When my pals were reading comic books
I was down in the basement in my dad's
workshop. Perusing his Sam's Photofoacts
Vol 1-50 admiring the old set and trying to
figure out what all those squiggly meant.
Circa 1966
Now I think I've got!
Terry
Posts: 42
Threads: 7
Joined: Apr 2009
All of my voltages are good and the radio plays - one station. I took a modulated 1620 kHz radio signal and applied it through the antenna through a 100pF capacitor. The ground was connected to the common through a 0.1 uF capacitor. After turning the station selector as far clockwise as possible I adjusted the RF and RF trimmers to get maximum volume. After changing the radios signal to 580 kHz I could tune in the signal by turning the selectors almost as far counter clockwise as possible. If I go too far, the radios growls.
I can only pickup one station at two frequencies and I'm not sure why. This seems very odd but I did have to restring the coils. Unless that needs to be very precise (and yes it is a pain in the backside to do) I'm at a loss now. I tried to check the capacitance of the mica caps by the meter I have reads them very high, even new ones that I have bought. I've never had much success measuring capacitance of a wired part. The radio is not very valuable but I would like it to operate well enough to reassemble it and the clock and have both work just to do it. Any one have any suggestions?
