Philco 34

[Geist]

Hi All;
I just got a Philco 34 (Farm) Radio.. It is my first Philco.. It is Chassis and Speaker, no cabinet..
I am wondering, if it is similiar to any of the other Philco models that had Transformers (AC) in its circuitry, since it is a Battery set ?? If it was not a Battery Set, what would it be ??
THANK YOU Marty

[47'Plymouth]

You could sub the speaker with PM spkr with 20 watt,1100-1500
Ohm resistor for the field coil load,..an a audio output tranny that
Matches the output tube which is a 1A5 or 3Q5....Jody

[Geist]

Hi All;
Actually the Speaker is a Magnet type of Speaker, it has no Fiels Coil, since it is a Farm Battery set.. On the Philco site I have been told that the type model 44 will help me.. The Output tube is a type 19..
THANK YOU Marty

[Reece]

The 34 uses direct-heated filament cathodes: any AC sets would have used indirectly heated cathodes and different tubes, so this set is "its own self." The schematic shows all the voltages required to run it: your best bet would be to use one of the solid-state compact power supplies for it. Note: there is no field coil on the speaker; it's an early PM. If it doesn't sound so hot a more modern PM speaker can sub.

[Geist]

Hi All;
I got it today..
The Speaker is wrecked, but, I already knew that from the picture when I bought it.. So it will need to be re-conned.. But, the Voice coil works, its resistance is 1.8 Ohms, and with a "D" Battery it will move up and down..
All the tubes came unbroken, and only one tube that ohms out bad on the filaments, but it had "Bad" already written on it..
It seems in fairly good condition underneath..
On top it is caked witth dirt, grime and rust.. But, I am very pleased..
So, far all the coils that I have checked seem to be ok, as well as the two transformers..
Most of the resistors are ok, a few are way off..
I am going to need to build a battery eliminator for it..
THANK YOU Marty

[DavGoodlin]

Battery eliminators for the B battery are easy to build but go real easy on those filaments.

Try a 1.5 volt battery (or 4 in parallel) for the filament supply first, it can be tricky building a well-regulated supply for such a low voltage

[Geist]

Hi All;
Dave, Thank You for the Heads up, and the warning.. I thought a "D" battery might work, but wasn't sure If it was too low to light the tube..
I have a schematic for a good battery eliminator, its uses an LM317 to keep the voltage regulated, and I suppose I could also throw in a Zener as well..
It will need to be expanded from what it could power, as This Philco also uses ++135 volts as well as the +67.5 volts, it also has two negative Bias voltages -3 and -7.50.. So, I will have to get out another wooden Board and get things "right" before I try to connect to the radio at all..
THANK YOU Marty

[Geist]

Hi All;
Well I got something coming thru the set.. After playing with the various compensating capacitors, I got the Oscillator frequency close enough to start receiving stations.. I still have a ways to go to get the last 10K or so, but at least I know it is workable..
Would I need more capacitance or less to get the additional 10 to 15 K out of the Oscillator ??
I found that even moving one of the compensating capacitors up and down over the coil its mounted above, will make a difference in the oscillator frequency.. And of course touching the cap with my fingers will do the same..
I have an old Plastic stick, from Radio Shack that almost fits over most of the nuts that need adjustment.. I have had it for years..
Since I am using as my first IF a Miller 455KC IF can, and it has long leads to it, I have lots of squeeling and such.. So, I am going to put in the 1st IF can the IF Transformer that I bought from "Plaything of the Past" once I figure out how to wire it correctly..
This can has 4 wires coming out of the bottom, and I need to change it to 3 bottom and one on top.. I know how to find the two seperate coils, I just have to make sure they are orinated the same as the old one.. And that should eliminate much of the squeels and such..
THANK YOU Marty

[Reece]

If you need the oscillator to go higher in frequency, you need less capacitance in an L/C tuned circuit.

[Geist]

Hi All;
Thank You Reece, for Your answer, that is Exactly what I needed to know.. Still trying to chase things down to see what all is wrong, right now I am working on making sure that the Tuning Capacitor is properly Grounded and that there was no problems with the Trimmer Caps on top of the Tuning Cap.. Before I ask for any further help, I am going to make an attempt at checking everything multiple times.. Thank You for your help.. I can get it to work some and then it quits working, which is why I am checking the Tuning cap and associated wiring..
THANK YOU Marty