Assuming it's the speaker matching xfmr, measure the DC resistance of the speaker voice coil (disconnected from the xfmr secondary). Then I can make an educated guess.
What is the specific transformer you are looking at from RadioDaze?
The important thing about such a xfmr is the turns ratio.
Doug
:I have my Philco Model 20 working very nice with a different speaker. I wold like to get the original speaker working. Checked the audio transformer and it seems to be open, it is in terrible shape. Field coil checks at 3.2K ohms, sounds a little high but at least it is not open. Radio Daze has a universal replacement push/pull audio transformer that I think would work. In order to set this up I would need to know the impedance of the original audio transformer, since that has a open coil this is hard to find. Checked my schematic but no luck. Does anyone have access to the audio transformer impedance?
:Thanks
The transformer I am refering to is the one mounted on the back of the speaker, if I can read the number on the schematic I think it is #28. If you are looking at #27 it appears to be a choke. The replacement audio transformer from Radio Daze is HX125C.
Thanks
:George, there are two audio xfmrs. Are you talking
about the speaker matching xfmr? Here is the schematic: http://www.nostalgiaair.org/PagesByModel/582/M0029582.pdf
:
:Assuming it's the speaker matching xfmr, measure the DC resistance of the speaker voice coil (disconnected from the xfmr secondary). Then I can make an educated guess.
:
:What is the specific transformer you are looking at from RadioDaze?
:
:The important thing about such a xfmr is the turns ratio.
:Doug
:
:
::I have my Philco Model 20 working very nice with a different speaker. I wold like to get the original speaker working. Checked the audio transformer and it seems to be open, it is in terrible shape. Field coil checks at 3.2K ohms, sounds a little high but at least it is not open. Radio Daze has a universal replacement push/pull audio transformer that I think would work. In order to set this up I would need to know the impedance of the original audio transformer, since that has a open coil this is hard to find. Checked my schematic but no luck. Does anyone have access to the audio transformer impedance?
::Thanks
The voice coil resistance is 1.5 ohms
:
:Thanks
:
::George, there are two audio xfmrs. Are you talking
:about the speaker matching xfmr? Here is the schematic: http://www.nostalgiaair.org/PagesByModel/582/M0029582.pdf
::
::Assuming it's the speaker matching xfmr, measure the DC resistance of the speaker voice coil (disconnected from the xfmr secondary). Then I can make an educated guess.
::
::What is the specific transformer you are looking at from RadioDaze?
::
::The important thing about such a xfmr is the turns ratio.
::Doug
::
::
:::I have my Philco Model 20 working very nice with a different speaker. I wold like to get the original speaker working. Checked the audio transformer and it seems to be open, it is in terrible shape. Field coil checks at 3.2K ohms, sounds a little high but at least it is not open. Radio Daze has a universal replacement push/pull audio transformer that I think would work. In order to set this up I would need to know the impedance of the original audio transformer, since that has a open coil this is hard to find. Checked my schematic but no luck. Does anyone have access to the audio transformer impedance?
:::Thanks
Bill
:I have my Philco Model 20 working very nice with a different speaker. I wold like to get the original speaker working. Checked the audio transformer and it seems to be open, it is in terrible shape. Field coil checks at 3.2K ohms, sounds a little high but at least it is not open. Radio Daze has a universal replacement push/pull audio transformer that I think would work. In order to set this up I would need to know the impedance of the original audio transformer, since that has a open coil this is hard to find. Checked my schematic but no luck. Does anyone have access to the audio transformer impedance?
:Thanks
Thanks for the info, that helps.
:George, your field coil measuring 3200 ohms is ok, a parts list I have indicates 3100. Your output transformer is 100 to 1 turns ratio. What that means is I go to a cheat sheet and get something 8000-10000 CT Z ohms. And if I had something laying around in the 6000 ohms I would try it.
:
:Bill
:
::I have my Philco Model 20 working very nice with a different speaker. I wold like to get the original speaker working. Checked the audio transformer and it seems to be open, it is in terrible shape. Field coil checks at 3.2K ohms, sounds a little high but at least it is not open. Radio Daze has a universal replacement push/pull audio transformer that I think would work. In order to set this up I would need to know the impedance of the original audio transformer, since that has a open coil this is hard to find. Checked my schematic but no luck. Does anyone have access to the audio transformer impedance?
::Thanks