Newest Philco AA5?

[DavGoodlin]

I know its probably the most boring AM radio in the entire forum. But I am giving it to a friend who works at a Ford dealer.

In 1967, Philco added "tuning eye" tubes to some its color TV models, while tuners and IF stages were solid state. Some other funny stuff seemed to happen like adding the name of its new major shareholder, Ford.

Philco R-512.jpg

Japanese-made Philco-labeled tubes, speaker, IF cans and 2-section electrolytic BUT a very Philco PCB and USA assembly methods.

Just for shits and giggles, I wanted to see if the average performance could be "improved", so I did these funny little things I sometimes do to make these survivors present a bit better to the casual observer. These parts were donated by one of many computer monitors I scrapped.

R512.jpg

1. Add a 470 mf-16v cathode bypass cap across the 150 ohm resistor from 50C5 pin 2 to ground (sets bias) and .....it got louder with a bit more bass. (usually does not faze zeniths, which usually employ de-emphasis feedback)

2. Add a 600 ma fuse (it needs the safety sleeve) for protection and CL-90 thermistor to limit inrush to compensate for lack of the pilot lamp across the 35W4 filament.

3. Add a line reactor filter to STOP the usual AM buzz that was evident last night as I tuned across the dial. Doing this to some radios results in no improvement, even if safety caps are tried to form a trap filter.

If there was an additional RF amp tube (AA6) the AVC would work better and there would be more sensitivity, but it picks up more than "digital tuner" boomboxes and the like. The oddest thing is, the ferrite bar seems to pick up better on the long sides unlike some other sets I have. I thought moving it up and away from the chassis might improve things?

This makes some sets "not original" but it makes them safer, reliable and sound more like a Zenith.