[MrFixr55]

Hi Jeffcon,

First off, Welcome to the Philco Phorum!, a Phamily Phriendly Phorum, Phull of Phine Phriendly Pholks and Phun Philco Phacts. (See a pattern here?). Attached below is a link to the Philco History section of the Philco Library:
https://philcoradio.com/library/index.ph...o-history/

Sorry if this post is TMI, this is what I do.

This is a very interesting project, likely a mid to late 1960s product. The radio receiver represents maybe the last of American designed and built moderately priced and mid-range "HiFi". No Fisher or Scott, but a good performer. The turntable is likely the US built "V-M" (Voice of Music) or a British Garrard unit. the cartridge is likely ceramic, as very few consoles other than High End units like Fisher or Scott used the superior magnetic cartridges. You are preserving an important piece of American consumer electronic history.

"+1" on what the other members stated. Most of our interests are in tube radios from the early 1920s (beginning of consumer radio) to the early 1960s (end of tube radios) but many of us have interest in solid state radios also. I will elaborate on some points made and add some of my own.

In general, tube amps do not like to be run without some sort of "load" (usually a speaker). A shorted speaker on the secondary of the output transformer usually will not bother a tube radio. However, transistor amps are exactly the opposite. If I had a nickel for every solid state amp or receiver that I had to replace the output transistors in because one of my friends took four 8 Ohm speakers and wired them in parallel, I would be rich!

In other words, solid state amps and receivers are not tolerant of shorts, especially in the output stage.

You will hear the term "re-cap" (replacing most or all capacitors) very often in this hobby. Capacitors are used for 3 things. To filter pulsating DC into flat DC, to pass an AC component wile blocking DC or to be part of a "tuned circuit". Capacitors fail 3 ways. They either open, leak or short. An open capacitor does not pass a signal or filter the power. A leaking cap will pass some amount of DC (which should not happen. A shorted cap is very bad as it will either short out a power supply or pass a DC voltage where it will not be tolerated. While current capacitor technology is very good, with mylar capacitors lasting almost indefinitely and new electrolytic capacitors lasting 30 or more years, this was not the case in the 1960s. "Paper-Foil caps (usually 0.1 uF or less) will become electrically leaky, short or become noisy by intermittent short or leak due to breakdown of the "dielectric". Electrolytic caps will open as the electrolyte dries up or dead short. Open caps will cause hum shorted caps will cause major damage if in the power supply or output stage.

Unfortunately, solid state amps and electronics use many more electrolytics than tube amps. Whereas most coupling caps in tube circuits are 0.1uF or less, coupling caps in solid state amps are 10 uF to 1,000 uF or more. This makes for a more expensive restoration, as these "caps" (shorthand for capacitor) are usually more expensive than the mylar caps that replaced the paper-foil caps.

Because so many of the capacitors are electrolytic, it is recommended that all caps be replaced. At the very least (and i DO MEAN very least), replace the output caps and the filter caps.

A "dim bulb" tester is simply an easy to build device where you place an electrical outlet in series with 1 to 3 light sockets in parallel. The sockets are loaded with incandescent light bulbs. the wattage sed depends on the wattage of the electronic device being tested. For this radio, you would want low wattage lamps such as 25 Watt. the concept is that the brighter the bulb, the more current is being drawn by the device (application of Ohm's Law). In addition, by using a low wattage lamp, this will allow a lower voltage to be delivered to the device under test, allowing for "re-forming" of electrolytics. Especially for solid state devices or for unrestored devices, some hobbyists use a "Variac" (the brand name of an infinitely variable voltage transformer.

The output transistors are in sockets. Removing and replacing them may help "clean" the contacts. Transistors have 3 elements- the Emitter, the equivalent of a tube's cathode, the Base, the equivalent of the grid, and he Collector, the equivalent of the plate. This is an oversimplification, but it works. In a "TO3" cased transistor, like your output transistors, the case is the collector connection and this is above chassis ground. Therefore the mica insulator or its equivalent must be in place, and both sides of the insulator must be coated with heat conductive electrically insulating grease, available from many sources on the internet.

This set likely uses printed circuit boards (PCBs). One can't use a 100 Watt "Big Bertha" soldering iron on these. The internet should be full of soldering / desoldering techniques for PCBs. Very often, these boards are soldered to the pins of the metal chassis that the PCB is mounted to. Very often, the chassis, not the PCB completes the common ground for the circuit. In other words, the "ground plane" is not complete on these PCBs. Therefore, each connecting point between the PCB and chassis is important. Very often, these joints are bad, causing noise and intermittent operation. I like to add a wire ground to the chassis from these ground points.

Consoles of this vintage usually use a large 10 or 12 inch speaker as a full range speaker or as a "woofer" and possibly a small speaker as a "tweeter". These are not usually "high end" speakers and if large, or if the cabinet set outside for any period of time the cone can warp, causing the speaker "voice coil" to rub against the field magnet pole causing a very annoying scratchy sound. This may be more prominent on one speaker than the other.

Use a "Divide and Conquer" troubleshooting technique. Substitute another amp to test the speakers or substitute other speakers to evaluate the amp. CAUTION! Start out with speakers of 8 Ohm or higher! If the set has an "Aux" input, plug a known good tape deck, CD or DVD player, etc. into the Aux input. This will help you determine if the sound quality issue is due to the amplifier or radio section of the receiver.

Finally, once you get the electronics where you want it, consider upgrading the turntable to a magnetic cartridge (requires a preamp) and then tackle the cabinet (plenty of our members are experts on refinishing cabinets.

Good luck and keep us posted! We are always happy to help!!!