My 1st Philco Restoration - 46-350
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Hi everyone. I'm a 43 year old programmer in the Bay area and
recently acquired a Philco 46-350 from my folks while visiting
with my wife over Turkey Day.
This radio has been in my family since my Father brought this home to my
Mom sometime in the late 60's.
I remember this radio from my young childhood (tinkered with the tubes).
I have found a great amount of literature on this radio seeming how it
was very popular (think Sony Walkman) and low-cost back then.
I have a large electronics background (military and commercial) but
do not seem to use it much now-a-days. Here is a great
reason to get back into the saddle!
I will post updates occasionally and share although I'm sure
this project pales in comparison to some of the ones I've seen here ;)
Thanks for this great community resource!
Fred Myers
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I have restored several of these, and believe me, they stand their own as sensitive AM receivers. You can dig up a free schematic on Nostalgia Air or for a better version visit http://www.philcorepairbench.com/index.htm - well worth the small fee charged.
Now then, you will want to do a wholesale replacement of all the electrolytic (very careful on polarity,)and paper capacitors in the set, and any out of tolerance carbon resistors (I replace 'em all, cheap enough.) If the candohm measures OK and has not any shorts to chassis, leave it in. Looks like you need tubes, none of them are rare or expensive. This forum has a WTB section, and someone may have a set available at a very reasonable cost. I'm tapped out on these at the moment.
The belt handle is usually rotten, and believe it or not, replacements are available, or you can make one out of a, well, belt.
The only tricky part is making sure the 8.5 volt DC filament supply does not run high, as the filaments in these battery/AC sets are very delicate. Today's line voltage is higher, so an additional series resistor might be needed to tame the power. You can do without the half wave rectifier (117Z3) and substitute a silicon diode. If you do this you will have to place an additional resistor in series at the beginning of the voltage divider and you will use a 10 watt chassis mount or sand resistor dressed to the chassis to dissipate heat.
The battery/AC interlock switch is also a real pain. If you want, you can just get rid of it, make the proper connections as if it wasn't there, and you'll be glad you did. That is unless you want to spend a bunch of money and time creating an ersatz AB battery pack, which of course could still be done. There are folks on this forum that make 'em.
Nice winter project, take your time. If you run into a real problem, like a wasted coil, these sets do come up all the time on Ebay, and can be had for not much money. I know we will be hearing from you soon.
I've all but hung up my mouse too, lapsed radio tinkerer for decades. Lots of us here.
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Thanks! Been speaking with Wayne about a new strap and will pick his brain
a bit. As for the rectifier modification, I haven't decided yet. I want to keep
it period enough and from my reading I understand that doing this
will cut down on the on-time (warm-up).
As to the switch, it looks to be in good working order but will have
to look at it. But doing the battery from what I have seen is kind of a
pain in the rear and might leave the switch but direct connect it.
Hoping I do not have to replace any coils.
For now, I'm going to do some documentation as to various component
values and see what I need to order.
If the audio transformer turns out to be bad, where do you recommend
I go. I haven't found much (yet) as to sources.
Take care!
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City: Sandwick, BC, CA
I have two of these things, one is Canadian made the other U.S made. I haven't encountered any problems with the battery/AC interlock switch on mine, just the usual capacitors and resistors including a bad mica in the oscillator circuit, it's nothing more then a spring loaded slide switch so if you give it a good cleaning it shouldn't cause any trouble. One thing that I should warn about, the chassis in theses sets are cramped, the underside of it not only has to fit the caps and resistors but the back side of the speaker as well. If I were you I would keep the 117Z3 tube in the circuit, they work perfectly fine, are inexpensive to replace, and they only take maybe 30 seconds to warm at most, if you use a diode then you will have to figure out where to mount a 10 Watt resistor somewhere on the cramped chassis. It would be rare for a power output transformer to be bad in one of these sets but if it is you can salvage one off of another battery set or portable using a 3V4, 3Q5, etc.
Regards
Arran
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Yea. Good point about the space and finding a good place to vent off the heat
from the sand resister. As to the switch, it looks to be in good order.
Anyone ever had problems with the tuning cap (air)?
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The most common tuning cap problem would be plates contacting each other. After that comes intermittant, open, or shorted leads to the upper or lower portion of the cap. Although I doubt that you would have this problem with this model radio, loud/scratchy tuning can often be attributed to metal on metal contact somewhere in the tuning mechanism.
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Freddy Wrote:Yea. Good point about the space and finding a good place to vent off the heat
from the sand resister. As to the switch, it looks to be in good order.
Anyone ever had problems with the tuning cap (air)?
I don't know why sand resitors are being brought up, I don't know where you would get one of those these days but the old ones that they used to use in TVs were junk. The square porcelain wire wound ones are much better in that you can attach one side to the chassis as a heat sink, better still are the type with the aluminum shell that you can screw to the chassis, but again chassis space is at a premium in one of these sets never mind the ventilation. If your line voltage is around 120 V I wouldn't worry about dropping it, if it's above that I would build an external dropping device that you can plug the set into, including either a large wire wound resistor or a bucking transformer to knock the input voltage down 5 to 10 volts. Some would say more but 1R5 tubes are very fussy about how much B+ voltage they get, if it drops too much then it may stop oscillating.
Regards
Arran
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Going to replace caps and resistors and then use isolation xformer to check
B+'s before I start popping tubes into place.
Was thinking about using mild solution to remove oxidization from the tuner cap
and then lubing it with a silicon-based lubricant (tuner cleaner).
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Freddy Wrote:Going to replace caps and resistors and then use isolation xformer to check
B+'s before I start popping tubes into place.
Was thinking about using mild solution to remove oxidization from the tuner cap
and then lubing it with a silicon-based lubricant (tuner cleaner).
I would just stick to regular or lithium grease in the luning condenser bearings, I know they push that silicone junk everywhere now but it often causes as many problems as it solves, tuner bath or soap and water will work to clean it, I use a TSP solution but I'm not going to suggest that . To test the B+ you will need to put the 117Z3 rectifier tube in place, also make sure the set is off before inatlling the battery tubes or they may be blown.
Regards
Arran
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I like these too. They perform really well. Here is a link to philco factory service manual for this one, but you'll have to install dajavu.
http://www.audiophool.cjb.net/Misc/philco_46-350.djvu
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Just to clarify, been calling modern square wirewounds "sand resistors" for a long time. I stand corrected. As for space, there's tons of space underneath the set where the battery would go for a bucking transformer or power resistor if needed; just be careful not to create a shock hazard.
When you get your parts list done, include the mica resistors in the if cans. I had two bad ones. You don't need to replace them unless you run into symptoms of "Silver Mica Disease," but at least you will have them at hand.
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>When you get your parts list done, include the mica resistors in the if cans.
Not trying to be picky but did you mean mica caps?
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
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Yea, I think he meant mica caps 
Def going to give the whole thing a nice bath. Hoping I can leave
the micas in-place as the process to replace them just adds more
fun fun fun!
Thanks for the pointers. I have the schematics and service info coming
and will be prying into this next weekend.
Fred
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The ones in the RF can and second IF can 10 and 100 mf silver micas. Don't change them out unless you have to, because it is a PIA to take the cans apart.
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