[Radioguy52]

Tried reversal of 1 and 3.. no reception at all.  with it hooked up by the drawing I receive 770 kc on 900 kc dial and others all up the dial but never below.  Note this is a 470 kc IF radio and the coil is spec at 455KC IF.  No adjustments on the coil makes a difference.  I can slightly shift the frequency by adjusting 3B ..

[Mondial]

Cab you post a picture of the tuning slug from the replacement osc coil? Unless the slug is made of some unknown unusual material, it seems impossible that moving it in and out of the winding would have no effect on the osc frequency.

If the slug is made of ferrite or powdered iron, it will lower the resonant frequency of the coil when inserted. If made of aluminum, copper or brass it will raise the freq.

Since your osc appears to be too low for the received freq, try removing the slug and insert a small brass or aluminum rod or screw into the coil and see if it acts to reduce the error in receive freq vs the dial setting.

[Radioguy52]

Not sure if this is a clue but I ran a 550 KHZ signal from my signal generator and a clear sound with the dial at around 700

[Radioguy52]

Hope maybe I am not on the wrong track.  I substituted another "OS coil" pulled from a like kind chassis found on eBay.  Ohms on the coil looked good 3.5/6 ohms PN #32-3021.  Although not exact rr coil it responds just like the universal OS I tried .  My symptoms are as follows.  I get reception.  (Prior issue was no reception and open OS coil)  Reception is only from aprox 770KC to 1080KC all appearing higher on the dial.  EX  820 is showing around 1100.  Tried to adjust the Compensator 3B-3A  .  moved the signal a little but very little,  There is an adjustment on the underside of the tuning Condenser similar to the top 3B.  Slight change but not significant.  I have ohm the 51K resistor out of ckt and it measures 56K.  The 110 uf measures 160UF out of ckt.  Enclosed are my V measurements on the 6A&.  *I have also substituted the 6A7 and 78 tubes for trial.  Can't seem to understand why the frequencies are so far off .  IF adjustment has some slight up/down but nothing .  Lower frequency channels do nit register.  550KC to aprox 700.  

[Chas]

Unless someone has used the same "universal" oscillator coil installed in the same receiver and had satisfactory results, IMHO this coil is not working here...

You have provided one picture of the oscillator coil in question, apparently it "looks" very good... If a couple more images could be posted to this thread, I would be encouraged to look through the used coil box I have to see if I can find an identical coil... The images may also help someone else look in their storage too. Radio part "junque" boxes rarely label parts as to their source so it is a visual comparison...

Again, if the coil form and the windings are intact, meaning no attempt to unwind, thus loosing the turns count the old coil could be re-wound...

Chas

[Radioguy52]

These are the three coils .  The original was open and my attempts to replace with a Universal or the older harvested from another similar philco were partialy successful but I still have the lower frequency reception gone 570-770 and the higher 820-1080 apearing way higher on the scale,

[mikethedruid]

Maybe a dumb question on my part, but did you try adjusting the slug in the center of the universal oscillator coil to see if it shifted the tuning?

[Radioguy52]

I have tried to adjust the slug. It does modify the frequency but slightly. No where near getting back the lower stations or moving existing to a lower status on the band indicator.

[David]

Restored a 38-15 app 10 years ago rewinding the coil is something you can do. Count number of turns before removing  each winding and note direction of rotation of each remember the direction of rotation is the way it will be installed not removed do not ask me why I know this is so important! Wire size important, some sets of this time frame had sulfur in the wax to make the wax softer does not play well with copper over the years. Just get some bees wax and good luck.

[Radioguy52]

UPDATE:
It appears the Universal sent was marked wrong and did not match the phorum . Combined I think I was chasing dual issue.

• For the record the OS schematic turns out to be wrong. The Pin 1 designation red dot is off by one. It looks like if I use correct 1-2 at 5 ohms an 4-5 at 2.2 the OS comes into more accurate range as related to the dial calibration. And I can now tweak the coil slug for more variation.