Am I correct in assuming a bad 117Z3? Could the bad tube be responsible for low resistance between pins 3 and 6 and incorrect voltage at E to B-?
Any help would be appreciated.
Filament of a 117Z3 are on pins #3 and #4. If the tube lights it's ok for now.
Pin #6 is cathode, B+ output. This pin should have around 105 volts DC when measured to B-. You can measure this voltage across the first filter capacitor. If this voltage is very low the 117Z3 may be bad. If very high series filament resistor may be open?
Filament of radio tubes will be powered through a large wire wound resistor. In operation this resistor will be very warm. Sometimes it opens, then you will not have any filament voltage on radio tubes.
Any tube filament open will stop all others from operating. In this case A+ to A- will be high.
Norm
:I recapped the radio and am in the process of troubleshooting IAW Philco Service Manual. Here is what I have found so far:
:Preliminary checks - A+/A- shows open circuit. Resistance of 2500 ohms between pins 3 and 6 of 117Z3.
:Section 1 - E to B- voltage was 46.5.
:
:Am I correct in assuming a bad 117Z3? Could the bad tube be responsible for low resistance between pins 3 and 6 and incorrect voltage at E to B-?
:
:Any help would be appreciated.
Volatage between B+ and B- was 114v. The service manual says it should be 90. A+ to A- resistance was 2500 Ohms - much higher than manual states (100 ohms).
So at this point it looks like either bad tube filament(s) or open wire wound resistor. I believe this resistor is the filament resistor R100 in schematic? If so, it is actually 3 separate resistors connected in series and housed in a casing that is riveted to the chassis. If it's bad, what do you suggest for replacement?
Thanks,
Kevin
:Hi Kevin
:
: Filament of a 117Z3 are on pins #3 and #4. If the tube lights it's ok for now.
:
: Pin #6 is cathode, B+ output. This pin should have around 105 volts DC when measured to B-. You can measure this voltage across the first filter capacitor. If this voltage is very low the 117Z3 may be bad. If very high series filament resistor may be open?
:
: Filament of radio tubes will be powered through a large wire wound resistor. In operation this resistor will be very warm. Sometimes it opens, then you will not have any filament voltage on radio tubes.
:
: Any tube filament open will stop all others from operating. In this case A+ to A- will be high.
:
:Norm
:
::I recapped the radio and am in the process of troubleshooting IAW Philco Service Manual. Here is what I have found so far:
::Preliminary checks - A+/A- shows open circuit. Resistance of 2500 ohms between pins 3 and 6 of 117Z3.
::Section 1 - E to B- voltage was 46.5.
::
::Am I correct in assuming a bad 117Z3? Could the bad tube be responsible for low resistance between pins 3 and 6 and incorrect voltage at E to B-?
::
::Any help would be appreciated.
If one of the filaments is open the voltage on the 117Z3 cathode will probably be a little higher than the schematic because the tubes are not drawing current (or perhaps a section of the filament resistor is open) and also the voltage may be higher because the radio may have originally had 117 VAC input instead of the 120VAC today. The resistor you mention is a 60/875/875 Ohm resistor. If a section is open you can bridge it with a wirewound resistor(s) of appropriate value and probably 5 watts or so. You can test the filaments of the tubes by measuring the resistance between 1 & 7 of the mini tubes and 2 & 7 of the octal output tube.
Radiodoc
*************
:Thanks, Norm.
:
:Volatage between B+ and B- was 114v. The service manual says it should be 90. A+ to A- resistance was 2500 Ohms - much higher than manual states (100 ohms).
:So at this point it looks like either bad tube filament(s) or open wire wound resistor. I believe this resistor is the filament resistor R100 in schematic? If so, it is actually 3 separate resistors connected in series and housed in a casing that is riveted to the chassis. If it's bad, what do you suggest for replacement?
:
:Thanks,
:
:Kevin
:
:
::Hi Kevin
::
:: Filament of a 117Z3 are on pins #3 and #4. If the tube lights it's ok for now.
::
:: Pin #6 is cathode, B+ output. This pin should have around 105 volts DC when measured to B-. You can measure this voltage across the first filter capacitor. If this voltage is very low the 117Z3 may be bad. If very high series filament resistor may be open?
::
:: Filament of radio tubes will be powered through a large wire wound resistor. In operation this resistor will be very warm. Sometimes it opens, then you will not have any filament voltage on radio tubes.
::
:: Any tube filament open will stop all others from operating. In this case A+ to A- will be high.
::
::Norm
::
:::I recapped the radio and am in the process of troubleshooting IAW Philco Service Manual. Here is what I have found so far:
:::Preliminary checks - A+/A- shows open circuit. Resistance of 2500 ohms between pins 3 and 6 of 117Z3.
:::Section 1 - E to B- voltage was 46.5.
:::
:::Am I correct in assuming a bad 117Z3? Could the bad tube be responsible for low resistance between pins 3 and 6 and incorrect voltage at E to B-?
:::
:::Any help would be appreciated.
:Kevin,
:
:If one of the filaments is open the voltage on the 117Z3 cathode will probably be a little higher than the schematic because the tubes are not drawing current (or perhaps a section of the filament resistor is open) and also the voltage may be higher because the radio may have originally had 117 VAC input instead of the 120VAC today. The resistor you mention is a 60/875/875 Ohm resistor. If a section is open you can bridge it with a wirewound resistor(s) of appropriate value and probably 5 watts or so. You can test the filaments of the tubes by measuring the resistance between 1 & 7 of the mini tubes and 2 & 7 of the octal output tube.
:
:Radiodoc
:*************
:
::Thanks, Norm.
::
::Volatage between B+ and B- was 114v. The service manual says it should be 90. A+ to A- resistance was 2500 Ohms - much higher than manual states (100 ohms).
::So at this point it looks like either bad tube filament(s) or open wire wound resistor. I believe this resistor is the filament resistor R100 in schematic? If so, it is actually 3 separate resistors connected in series and housed in a casing that is riveted to the chassis. If it's bad, what do you suggest for replacement?
::
::Thanks,
::
::Kevin
::
::
:::Hi Kevin
:::
::: Filament of a 117Z3 are on pins #3 and #4. If the tube lights it's ok for now.
:::
::: Pin #6 is cathode, B+ output. This pin should have around 105 volts DC when measured to B-. You can measure this voltage across the first filter capacitor. If this voltage is very low the 117Z3 may be bad. If very high series filament resistor may be open?
:::
::: Filament of radio tubes will be powered through a large wire wound resistor. In operation this resistor will be very warm. Sometimes it opens, then you will not have any filament voltage on radio tubes.
:::
::: Any tube filament open will stop all others from operating. In this case A+ to A- will be high.
:::
:::Norm
:::
::::I recapped the radio and am in the process of troubleshooting IAW Philco Service Manual. Here is what I have found so far:
::::Preliminary checks - A+/A- shows open circuit. Resistance of 2500 ohms between pins 3 and 6 of 117Z3.
::::Section 1 - E to B- voltage was 46.5.
::::
::::Am I correct in assuming a bad 117Z3? Could the bad tube be responsible for low resistance between pins 3 and 6 and incorrect voltage at E to B-?
::::
::::Any help would be appreciated.
I don't think the 117Z3 filament (I assume that is what you meant) should glow brightly when the radio is first turned on but should gradually light up to full brilliance after a couple of seconds. I just finished up a 46-350 recently but did not pay too much attention to the filament lighting up (the tube was a new old stock). Tomorrow I will observe the 117Z3 in the one I have when I turn it on. You have gotten my curiosity up. I'll let you know what I observe. You may have a 117Z3 with part of the filament shorted out.
Radiodoc
*********
:Thanks Doc, I think the filament resistor is OK. Resistances measured 65/905/905 Ohms. Both 1T5s seem to have open filaments so I will replace them. One observation that bothers me is that when power is turned on, the rectifier glows very bright then dims to a low glow. Is this normal?
:
::Kevin,
::
::If one of the filaments is open the voltage on the 117Z3 cathode will probably be a little higher than the schematic because the tubes are not drawing current (or perhaps a section of the filament resistor is open) and also the voltage may be higher because the radio may have originally had 117 VAC input instead of the 120VAC today. The resistor you mention is a 60/875/875 Ohm resistor. If a section is open you can bridge it with a wirewound resistor(s) of appropriate value and probably 5 watts or so. You can test the filaments of the tubes by measuring the resistance between 1 & 7 of the mini tubes and 2 & 7 of the octal output tube.
::
::Radiodoc
::*************
::
:::Thanks, Norm.
:::
:::Volatage between B+ and B- was 114v. The service manual says it should be 90. A+ to A- resistance was 2500 Ohms - much higher than manual states (100 ohms).
:::So at this point it looks like either bad tube filament(s) or open wire wound resistor. I believe this resistor is the filament resistor R100 in schematic? If so, it is actually 3 separate resistors connected in series and housed in a casing that is riveted to the chassis. If it's bad, what do you suggest for replacement?
:::
:::Thanks,
:::
:::Kevin
:::
:::
::::Hi Kevin
::::
:::: Filament of a 117Z3 are on pins #3 and #4. If the tube lights it's ok for now.
::::
:::: Pin #6 is cathode, B+ output. This pin should have around 105 volts DC when measured to B-. You can measure this voltage across the first filter capacitor. If this voltage is very low the 117Z3 may be bad. If very high series filament resistor may be open?
::::
:::: Filament of radio tubes will be powered through a large wire wound resistor. In operation this resistor will be very warm. Sometimes it opens, then you will not have any filament voltage on radio tubes.
::::
:::: Any tube filament open will stop all others from operating. In this case A+ to A- will be high.
::::
::::Norm
::::
:::::I recapped the radio and am in the process of troubleshooting IAW Philco Service Manual. Here is what I have found so far:
:::::Preliminary checks - A+/A- shows open circuit. Resistance of 2500 ohms between pins 3 and 6 of 117Z3.
:::::Section 1 - E to B- voltage was 46.5.
:::::
:::::Am I correct in assuming a bad 117Z3? Could the bad tube be responsible for low resistance between pins 3 and 6 and incorrect voltage at E to B-?
:::::
:::::Any help would be appreciated.
Some 117Z3's flash bright when power is first applied. Part of the filament is probably not coated so it heats first. This is more common in European made tubes.
Norm
:Kevin,
:
:I don't think the 117Z3 filament (I assume that is what you meant) should glow brightly when the radio is first turned on but should gradually light up to full brilliance after a couple of seconds. I just finished up a 46-350 recently but did not pay too much attention to the filament lighting up (the tube was a new old stock). Tomorrow I will observe the 117Z3 in the one I have when I turn it on. You have gotten my curiosity up. I'll let you know what I observe. You may have a 117Z3 with part of the filament shorted out.
:
:Radiodoc
:*********
:
::Thanks Doc, I think the filament resistor is OK. Resistances measured 65/905/905 Ohms. Both 1T5s seem to have open filaments so I will replace them. One observation that bothers me is that when power is turned on, the rectifier glows very bright then dims to a low glow. Is this normal?
::
:::Kevin,
:::
:::If one of the filaments is open the voltage on the 117Z3 cathode will probably be a little higher than the schematic because the tubes are not drawing current (or perhaps a section of the filament resistor is open) and also the voltage may be higher because the radio may have originally had 117 VAC input instead of the 120VAC today. The resistor you mention is a 60/875/875 Ohm resistor. If a section is open you can bridge it with a wirewound resistor(s) of appropriate value and probably 5 watts or so. You can test the filaments of the tubes by measuring the resistance between 1 & 7 of the mini tubes and 2 & 7 of the octal output tube.
:::
:::Radiodoc
:::*************
:::
::::Thanks, Norm.
::::
::::Volatage between B+ and B- was 114v. The service manual says it should be 90. A+ to A- resistance was 2500 Ohms - much higher than manual states (100 ohms).
::::So at this point it looks like either bad tube filament(s) or open wire wound resistor. I believe this resistor is the filament resistor R100 in schematic? If so, it is actually 3 separate resistors connected in series and housed in a casing that is riveted to the chassis. If it's bad, what do you suggest for replacement?
::::
::::Thanks,
::::
::::Kevin
::::
::::
:::::Hi Kevin
:::::
::::: Filament of a 117Z3 are on pins #3 and #4. If the tube lights it's ok for now.
:::::
::::: Pin #6 is cathode, B+ output. This pin should have around 105 volts DC when measured to B-. You can measure this voltage across the first filter capacitor. If this voltage is very low the 117Z3 may be bad. If very high series filament resistor may be open?
:::::
::::: Filament of radio tubes will be powered through a large wire wound resistor. In operation this resistor will be very warm. Sometimes it opens, then you will not have any filament voltage on radio tubes.
:::::
::::: Any tube filament open will stop all others from operating. In this case A+ to A- will be high.
:::::
:::::Norm
:::::
::::::I recapped the radio and am in the process of troubleshooting IAW Philco Service Manual. Here is what I have found so far:
::::::Preliminary checks - A+/A- shows open circuit. Resistance of 2500 ohms between pins 3 and 6 of 117Z3.
::::::Section 1 - E to B- voltage was 46.5.
::::::
::::::Am I correct in assuming a bad 117Z3? Could the bad tube be responsible for low resistance between pins 3 and 6 and incorrect voltage at E to B-?
::::::
::::::Any help would be appreciated.
I checked my Philco this morning and the filament lit up with normal brightness after a couple of seconds of turn on and a few seconds later the radio came on. Norm has a good point about some tubes having places on the filament that were not coated and would light brightly quickly at turn on. I had read about this but I guess I had forgotten. If the 117Z3 lights and has around 100 or so volts DC on the cathode I don't think I would worry too much about it.
Radiodoc
***********
:Hi
:
: Some 117Z3's flash bright when power is first applied. Part of the filament is probably not coated so it heats first. This is more common in European made tubes.
:
:Norm
:
::Kevin,
::
::I don't think the 117Z3 filament (I assume that is what you meant) should glow brightly when the radio is first turned on but should gradually light up to full brilliance after a couple of seconds. I just finished up a 46-350 recently but did not pay too much attention to the filament lighting up (the tube was a new old stock). Tomorrow I will observe the 117Z3 in the one I have when I turn it on. You have gotten my curiosity up. I'll let you know what I observe. You may have a 117Z3 with part of the filament shorted out.
::
::Radiodoc
::*********
::
:::Thanks Doc, I think the filament resistor is OK. Resistances measured 65/905/905 Ohms. Both 1T5s seem to have open filaments so I will replace them. One observation that bothers me is that when power is turned on, the rectifier glows very bright then dims to a low glow. Is this normal?
:::
::::Kevin,
::::
::::If one of the filaments is open the voltage on the 117Z3 cathode will probably be a little higher than the schematic because the tubes are not drawing current (or perhaps a section of the filament resistor is open) and also the voltage may be higher because the radio may have originally had 117 VAC input instead of the 120VAC today. The resistor you mention is a 60/875/875 Ohm resistor. If a section is open you can bridge it with a wirewound resistor(s) of appropriate value and probably 5 watts or so. You can test the filaments of the tubes by measuring the resistance between 1 & 7 of the mini tubes and 2 & 7 of the octal output tube.
::::
::::Radiodoc
::::*************
::::
:::::Thanks, Norm.
:::::
:::::Volatage between B+ and B- was 114v. The service manual says it should be 90. A+ to A- resistance was 2500 Ohms - much higher than manual states (100 ohms).
:::::So at this point it looks like either bad tube filament(s) or open wire wound resistor. I believe this resistor is the filament resistor R100 in schematic? If so, it is actually 3 separate resistors connected in series and housed in a casing that is riveted to the chassis. If it's bad, what do you suggest for replacement?
:::::
:::::Thanks,
:::::
:::::Kevin
:::::
:::::
::::::Hi Kevin
::::::
:::::: Filament of a 117Z3 are on pins #3 and #4. If the tube lights it's ok for now.
::::::
:::::: Pin #6 is cathode, B+ output. This pin should have around 105 volts DC when measured to B-. You can measure this voltage across the first filter capacitor. If this voltage is very low the 117Z3 may be bad. If very high series filament resistor may be open?
::::::
:::::: Filament of radio tubes will be powered through a large wire wound resistor. In operation this resistor will be very warm. Sometimes it opens, then you will not have any filament voltage on radio tubes.
::::::
:::::: Any tube filament open will stop all others from operating. In this case A+ to A- will be high.
::::::
::::::Norm
::::::
:::::::I recapped the radio and am in the process of troubleshooting IAW Philco Service Manual. Here is what I have found so far:
:::::::Preliminary checks - A+/A- shows open circuit. Resistance of 2500 ohms between pins 3 and 6 of 117Z3.
:::::::Section 1 - E to B- voltage was 46.5.
:::::::
:::::::Am I correct in assuming a bad 117Z3? Could the bad tube be responsible for low resistance between pins 3 and 6 and incorrect voltage at E to B-?
:::::::
:::::::Any help would be appreciated.