I am still experiencing problems with my Philco 84 restoration of many months...to recap: I have replaced all of the capacitors, resistors, transformer, and tubes. As of now, I am to the point where I can get any one station as loud as necessary by adjusting the trimmers, but the reception on the rest of the band is very weak. Adjusting the trimmers at another station yields higher volume, but then returning to other stations, I find that the volume is very low. There is also slight audio distortion that I can hear at low volume and does not seem to be from the speaker. Could this problem eminate from replacing the wire-wound resistors with carbon comp. type? I know that the wire wound coils will put a magnetic flux into the circuit of the radio that I might not be able to compensate for with the trimmers??? I am still searcing for ideas, and any help would be greatly appreciated.
Thanks,
Nicholas
Most likely the IF frequency isn't correct? This will cause a radio to peak at one place on the dial but not another. Philco 84 has 460 KC IF frequency. How are you setting this? Part number 15 on the schematic.
Types or resistors won't be a problem as long as they aren't overheating.
Sound might be heard coming directly from the audio output transformer. The core can vibrate but it won't be loud.
Norm
:Hello,
:
:I am still experiencing problems with my Philco 84 restoration of many months...to recap: I have replaced all of the capacitors, resistors, transformer, and tubes. As of now, I am to the point where I can get any one station as loud as necessary by adjusting the trimmers, but the reception on the rest of the band is very weak. Adjusting the trimmers at another station yields higher volume, but then returning to other stations, I find that the volume is very low. There is also slight audio distortion that I can hear at low volume and does not seem to be from the speaker. Could this problem eminate from replacing the wire-wound resistors with carbon comp. type? I know that the wire wound coils will put a magnetic flux into the circuit of the radio that I might not be able to compensate for with the trimmers??? I am still searcing for ideas, and any help would be greatly appreciated.
:
:Thanks,
:
:Nicholas
Jeff
:Hi Nicholas
:
: Most likely the IF frequency isn't correct? This will cause a radio to peak at one place on the dial but not another. Philco 84 has 460 KC IF frequency. How are you setting this? Part number 15 on the schematic.
:
: Types or resistors won't be a problem as long as they aren't overheating.
:
: Sound might be heard coming directly from the audio output transformer. The core can vibrate but it won't be loud.
:
:Norm
:
::Hello,
::
::I am still experiencing problems with my Philco 84 restoration of many months...to recap: I have replaced all of the capacitors, resistors, transformer, and tubes. As of now, I am to the point where I can get any one station as loud as necessary by adjusting the trimmers, but the reception on the rest of the band is very weak. Adjusting the trimmers at another station yields higher volume, but then returning to other stations, I find that the volume is very low. There is also slight audio distortion that I can hear at low volume and does not seem to be from the speaker. Could this problem eminate from replacing the wire-wound resistors with carbon comp. type? I know that the wire wound coils will put a magnetic flux into the circuit of the radio that I might not be able to compensate for with the trimmers??? I am still searcing for ideas, and any help would be greatly appreciated.
::
::Thanks,
::
::Nicholas
The 84 is not exactly a "hot" performer (it just looks classy), so you will have some audio noise, and sensitivity is not normally spectacular, but adequate.
If you are tuning by ear, always select a station at the top of the band to tune to for sensitivity. Tuning in the middle of the band, while easy to do, yeilds the poorest consistent results because the radio then becomes sensitive in only a narrow band near the middle range only.
:Hi:
:I have the same problem with the Philco 84 I'm restoring. One station is real loud and the rest faint, until I adjust the trimmer. Then the weak station becomes loud and the loud station fade out. I have the schematics, which tell what the IF freq should be and so on, but they don't tell where to connect the signal generator. I'm borrowing a generator from an acquaintance, and I think I can get thru the alignment process, but where is the generator connected in the circuit on this model?
:
:Jeff
:
::Hi Nicholas
::
:: Most likely the IF frequency isn't correct? This will cause a radio to peak at one place on the dial but not another. Philco 84 has 460 KC IF frequency. How are you setting this? Part number 15 on the schematic.
::
:: Types or resistors won't be a problem as long as they aren't overheating.
::
:: Sound might be heard coming directly from the audio output transformer. The core can vibrate but it won't be loud.
::
::Norm
::
:::Hello,
:::
:::I am still experiencing problems with my Philco 84 restoration of many months...to recap: I have replaced all of the capacitors, resistors, transformer, and tubes. As of now, I am to the point where I can get any one station as loud as necessary by adjusting the trimmers, but the reception on the rest of the band is very weak. Adjusting the trimmers at another station yields higher volume, but then returning to other stations, I find that the volume is very low. There is also slight audio distortion that I can hear at low volume and does not seem to be from the speaker. Could this problem eminate from replacing the wire-wound resistors with carbon comp. type? I know that the wire wound coils will put a magnetic flux into the circuit of the radio that I might not be able to compensate for with the trimmers??? I am still searcing for ideas, and any help would be greatly appreciated.
:::
:::Thanks,
:::
:::Nicholas
The 84 is not exactly a "hot" performer (it just looks classy), so you will have some audio noise, and sensitivity is not normally spectacular, but adequate.
If you are tuning by ear, always select a station at the top of the band to tune to for sensitivity. Tuning in the middle of the band, while easy to do, yeilds the poorest consistent results because the radio then becomes sensitive in only a narrow band near the middle range only.
:Hi:
:I have the same problem with the Philco 84 I'm restoring. One station is real loud and the rest faint, until I adjust the trimmer. Then the weak station becomes loud and the loud station fade out. I have the schematics, which tell what the IF freq should be and so on, but they don't tell where to connect the signal generator. I'm borrowing a generator from an acquaintance, and I think I can get thru the alignment process, but where is the generator connected in the circuit on this model?
:
:Jeff
:
::Hi Nicholas
::
:: Most likely the IF frequency isn't correct? This will cause a radio to peak at one place on the dial but not another. Philco 84 has 460 KC IF frequency. How are you setting this? Part number 15 on the schematic.
::
:: Types or resistors won't be a problem as long as they aren't overheating.
::
:: Sound might be heard coming directly from the audio output transformer. The core can vibrate but it won't be loud.
::
::Norm
::
:::Hello,
:::
:::I am still experiencing problems with my Philco 84 restoration of many months...to recap: I have replaced all of the capacitors, resistors, transformer, and tubes. As of now, I am to the point where I can get any one station as loud as necessary by adjusting the trimmers, but the reception on the rest of the band is very weak. Adjusting the trimmers at another station yields higher volume, but then returning to other stations, I find that the volume is very low. There is also slight audio distortion that I can hear at low volume and does not seem to be from the speaker. Could this problem eminate from replacing the wire-wound resistors with carbon comp. type? I know that the wire wound coils will put a magnetic flux into the circuit of the radio that I might not be able to compensate for with the trimmers??? I am still searcing for ideas, and any help would be greatly appreciated.
:::
:::Thanks,
:::
:::Nicholas
To recap: I had a working radio => sandblast and mica damage = distortion. So now, another question arises. If there is still mica present on the capacitor, would it's value have changed significantly enough by loosing a piece that it could not be compensated for by further adjsuting the trimmer? And if this is fatal, can it be repaired/replaced? Please let me know. (And thanks again everybody!)
:Hi,
:You can attach the the signal generator to the oscilator stator of the tuning condenser for aligning the IF's. And then to the antenna for Oscillator and RF adjustments.
:
:The 84 is not exactly a "hot" performer (it just looks classy), so you will have some audio noise, and sensitivity is not normally spectacular, but adequate.
:
:If you are tuning by ear, always select a station at the top of the band to tune to for sensitivity. Tuning in the middle of the band, while easy to do, yeilds the poorest consistent results because the radio then becomes sensitive in only a narrow band near the middle range only.
:
:
::Hi:
::I have the same problem with the Philco 84 I'm restoring. One station is real loud and the rest faint, until I adjust the trimmer. Then the weak station becomes loud and the loud station fade out. I have the schematics, which tell what the IF freq should be and so on, but they don't tell where to connect the signal generator. I'm borrowing a generator from an acquaintance, and I think I can get thru the alignment process, but where is the generator connected in the circuit on this model?
::
::Jeff
::
:::Hi Nicholas
:::
::: Most likely the IF frequency isn't correct? This will cause a radio to peak at one place on the dial but not another. Philco 84 has 460 KC IF frequency. How are you setting this? Part number 15 on the schematic.
:::
::: Types or resistors won't be a problem as long as they aren't overheating.
:::
::: Sound might be heard coming directly from the audio output transformer. The core can vibrate but it won't be loud.
:::
:::Norm
:::
::::Hello,
::::
::::I am still experiencing problems with my Philco 84 restoration of many months...to recap: I have replaced all of the capacitors, resistors, transformer, and tubes. As of now, I am to the point where I can get any one station as loud as necessary by adjusting the trimmers, but the reception on the rest of the band is very weak. Adjusting the trimmers at another station yields higher volume, but then returning to other stations, I find that the volume is very low. There is also slight audio distortion that I can hear at low volume and does not seem to be from the speaker. Could this problem eminate from replacing the wire-wound resistors with carbon comp. type? I know that the wire wound coils will put a magnetic flux into the circuit of the radio that I might not be able to compensate for with the trimmers??? I am still searcing for ideas, and any help would be greatly appreciated.
::::
::::Thanks,
::::
::::Nicholas
If the a chunk of it came out, there may still be enough present to keep it from shorting out if the radio functions. Slipping a new piece of mica, or plyethylene can solve the problems if it needs to be adjusted close.
One thing about abrasive blasting, Baking soda is best for two reasons. 1) it is less harsh as an abrasive, so it takes longer to clean a rusty surface, but is more controlable. 2) Cleanup is easy- Dip it in boiling water (or just the blasted portion,) or wipe it down with boiling water. The heat allows the water to dry quickly before much rust appears.
Sand may have abraided some wires, and one of those may be shorting against the chassis, or some other conductive surface, you may want to check your B voltages and grid voltages at each tube, and trouble shoot from there.
:I will definitely have to check the IF alignment this weekend in all my free time... :) The problem I am facing now with the distorted output came very recently, however. I had the radio working fine, and then I decided I needed to sandblast and repaint the transformer. (WOW! ANOTHER DUMB MOVE TO PUT IN THE LIST OF STUPID MISTAKES I HAVE MADE WITH THIS PROJECT! But I guess this is what you learn by restoring radios, yet another thing not to do in the future when I want to repaint my Zenith...) I taped up the chassis and speaker well, but once the blasting was done, I found sand where I didn't think it could get. Now I am wondering if some sand may have gotten inside the voice coil, and although it doesn't seem to rub when I push on the speaker cone, could this be the cause of distortion? I put another good philco 84 speaker in parallel with this one and I heard the same distortion, so I believe it must be in the radio. As if I can't make myself feel any worse, I will tell you that I also broke a piece of mica off one of the trimmers on the tuning condenser when I was transporting the radio.
:
:To recap: I had a working radio => sandblast and mica damage = distortion. So now, another question arises. If there is still mica present on the capacitor, would it's value have changed significantly enough by loosing a piece that it could not be compensated for by further adjsuting the trimmer? And if this is fatal, can it be repaired/replaced? Please let me know. (And thanks again everybody!)
:
::Hi,
::You can attach the the signal generator to the oscilator stator of the tuning condenser for aligning the IF's. And then to the antenna for Oscillator and RF adjustments.
::
::The 84 is not exactly a "hot" performer (it just looks classy), so you will have some audio noise, and sensitivity is not normally spectacular, but adequate.
::
::If you are tuning by ear, always select a station at the top of the band to tune to for sensitivity. Tuning in the middle of the band, while easy to do, yeilds the poorest consistent results because the radio then becomes sensitive in only a narrow band near the middle range only.
::
::
:::Hi:
:::I have the same problem with the Philco 84 I'm restoring. One station is real loud and the rest faint, until I adjust the trimmer. Then the weak station becomes loud and the loud station fade out. I have the schematics, which tell what the IF freq should be and so on, but they don't tell where to connect the signal generator. I'm borrowing a generator from an acquaintance, and I think I can get thru the alignment process, but where is the generator connected in the circuit on this model?
:::
:::Jeff
:::
::::Hi Nicholas
::::
:::: Most likely the IF frequency isn't correct? This will cause a radio to peak at one place on the dial but not another. Philco 84 has 460 KC IF frequency. How are you setting this? Part number 15 on the schematic.
::::
:::: Types or resistors won't be a problem as long as they aren't overheating.
::::
:::: Sound might be heard coming directly from the audio output transformer. The core can vibrate but it won't be loud.
::::
::::Norm
::::
:::::Hello,
:::::
:::::I am still experiencing problems with my Philco 84 restoration of many months...to recap: I have replaced all of the capacitors, resistors, transformer, and tubes. As of now, I am to the point where I can get any one station as loud as necessary by adjusting the trimmers, but the reception on the rest of the band is very weak. Adjusting the trimmers at another station yields higher volume, but then returning to other stations, I find that the volume is very low. There is also slight audio distortion that I can hear at low volume and does not seem to be from the speaker. Could this problem eminate from replacing the wire-wound resistors with carbon comp. type? I know that the wire wound coils will put a magnetic flux into the circuit of the radio that I might not be able to compensate for with the trimmers??? I am still searcing for ideas, and any help would be greatly appreciated.
:::::
:::::Thanks,
:::::
:::::Nicholas