[dmcraesho]

Hello All,

I am new to this Phorum and am looking for a little help. I'm sure this topic has been covered several times but what appreciate a little guidance. I have a 38-7 which I am trying to replace the old speaker with a new PM Speaker. The radio was a barn find and the speaker is beyond repair. I have refurbished the radio and all that it is lacking is a speaker. I have purchased a replacement speaker and audio transformer. What I am in need of is a little direction in hooking up the replacement. More specifically how to handle the current three wire output to two and where I need to install the filter choke. Any help would be greatly appreciated. Thanks in advance.

[klondike98]

Welcome to the Phorum!!
I'll add a link to the schematic for you so others have an easier time helping.  
I've not replaced a field coil speaker with a PM but others on the Phorum have and I'm sure will jump on here.  In the mean time here are a couple links to threads on related discussions on the Phorum:

http://www.nostalgiaair.org/Resources/256/M0013256.htm
http://philcoradio.com/phorum/showthread...speaker%22
http://philcoradio.com/phorum/showthread...speaker%22
http://philcoradio.com/phorum/showthread...speaker%22

this is just a few threads...there are more. 

[morzh]

You need to install a choke of equal or similar inductance and resistance instead of field coil, and then use matching speaker.

If your old speaker's field coil is good and you can remove it, you can use it. Keep it plugged exactly the way it was.

[codefox1]

Yup, and remember to also use the pole piece with the choke/field winding. Hope you have room for it.