Newest Philco AA5?
 

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.

Attachment 176036

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.

Attachment 176037

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 :music: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.:thmbsp:

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?:scratch2:

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

Kewl !

That really must be the last of the Philco tube radios. I see a Japanese speaker, output transformer and if transformers. I have twin speaker model that is simular to that one, but a little older. IIRC, it's has all USA parts. Not a bad radio.

Yep, its a nice little desk-warmer. I'll miss it.

can you add some more details about how to implement the line reactor filter? buzz drives me crazy on some of my radios

I was playing with a couple Philco AA5's earlier this year, both a little older than this one (I think the one was a '63?) and noticed the Japanese sourced, Philco-branded tubes. Odd, I think, that the NOS Philco-Ford tubes I have from that era are made in the US. I've noticed the same thing with DuMont/Emerson stuff. I wonder if this could possibly be a tariff issue? Perhaps if the tubes were incorporated into a radio they weren't subject to as high a tariff as if they were sold outright? Just an idea.

The line reactor interests me as well.

BTW if there is a small window around then that set should be mounted in it for April Fools day.....The thing looks JUST like a window air conditioner to me.

I have a '64 clock radio with a similar chassis. I think Philco started using the more modern Philco-Ford logo in '66; so, it's no older than '66 and more likely from '67 or '68. There was also a wooden cabinet version and was likely Philco's last series of tube radios.

So, Dave's radio is a "J5" then. :)

That double coil choke looks like the ones you find in old computer CRT monitors (which makes a good source of useful caps and resistors and such) and PC power supplies. Its purpose in the power supply is to cut down the leakage of RFI from the switching circuits onto the powerline. It may help to keep RFI out of a radio. I used one of these to impede the RF signal from a very strong local AM station from coming in on the powerline (I was getting "modulation" hum, when the RF sees a differing strength path via the power supply rectifier diodes, as the either conduct at the powerline peaks, or not conduct at the other times during an AC cycle). Just be sure you don't put one of the two coils across the powerline, it's not a transformer for 60Hz. Look at the PC power supply or PC monitor you pulled it from, you'll see how it's wired.

Safety and anti-EMI circuit
 

The Philco 'J5' radio (good one Chris) showed dramatic reduction in E M I buzz after implementing the circuit on my sketch. A 1959 GE clock radio also became usable after this fix.
Attachment 176122

The common-mode inductor and safety capacitor shown are from a Toshiba junker and the toroid came from a mid-70's GE color set IIRC. The common core inductor on the right is from a Zenith, but failed to block noise like the other two.. I usually save any line-voltage parts from my scrap-garden as they are VERY useful to upgrade the old stuff.:thmbsp:
Attachment 176123

I never have been able to track down the line-delivered harmonic noise source but dimmer switches, poorly grounded (T8 or T12) linear fluorescent lights seemed to affect AM. Higher-wattage compact fluorescent and 3/4 lamp electronic ballasts really affect weaker FM stations.

My Philco R512 looks like a window A/C unit like Tom has pointed out, :yes:but Philco made those too! I guess the design departments were the same. I suspect this radio was made in Sandusky, Ohio as Don Lindsley informed me there was a radio plant there in the 60s. Probably one without unionized assemblers who would willingly insert those Japanese tubes.:sigh: