Thanks Bill I really appreciate the help. You may be right but it appears to me that the two loops are part of the RF front end and are resonated on two bands. Looks like I may need to do some experimenting unless someone has one and wants to count the turns for me HIHI. 73, John, WA5BXO
-----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Bill Ramsey Sent: Friday, August 01, 2008 5:31 PM To: 'Discussion of AM Radio in the Amateur Service' Subject: RE: [AMRadio] Old Firestone radio Hi John, Take a look at the schematic that is found here: http://www.nostalgiaair.org/PagesByModel/312/M0006312.pdf It looks like it was just two loop antennas on the back cover. But, the schematic does show that there is a connection for an external antenna that can be used instead. Antique Electronic Supply has a couple of replacement loop styles that might work if you have the room on the back. Bill KA8WTK -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of John Coleman Sent: Friday, August 01, 2008 5:43 PM To: 'Discussion of AM Radio in the Amateur Service' Subject: [AMRadio] Old Firestone radio I am fixing an old radio for a friend of mine. It is a Firestone Air Chief S-7398-8 Picture found on the internet here http://radioattic.com/item_sold.php?radio=0002474X Replaced the 5Y3 rectifier and repaired the speaker. Believe it or not, the flexible wire from the cone connection of the voice coil was open. Only the string was left in the middle. I was able to tack a piece of solder wick to the top side of the voice coil wire and made a small hole in the cone then soldered the other end to the frame terminal. I then glued the small hole on the cone. I was afraid that something in the output XFMR or the hum bucker in the magnet assemble would be shorted that would have caused this but all check OK. The radio appears to be working now but there is a 4 pin connector on the chassis which I have determined to be for an antenna coil assembly connection. I believe there is supposed to be some type of wave magnet wound on the missing back. It is probably a multi tap or multi winding assembly with 4 wires that plug into the radio chassis. I do not know the specifications on this assembly as to whether it is part of some resonated RF circuit or just a loop or a few loops. Any info on the antenna coil assembles or schematic would be appreciated. Maybe I can manufacture something. TNX, 73, John, WA5BXO ______________________________________________________________ Our Main Website: http://www.amfone.net AMRadio mailing list Searchable Archives: http://www.mail-archive.com/amradio@mailman.qth.net/ List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net To unsubscribe, send an email to [EMAIL PROTECTED] with the word unsubscribe in the message body. ______________________________________________________________ Our Main Website: http://www.amfone.net AMRadio mailing list Searchable Archives: http://www.mail-archive.com/amradio@mailman.qth.net/ List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net To unsubscribe, send an email to [EMAIL PROTECTED] with the word unsubscribe in the message body. ______________________________________________________________ Our Main Website: http://www.amfone.net AMRadio mailing list Searchable Archives: http://www.mail-archive.com/amradio@mailman.qth.net/ List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net To unsubscribe, send an email to [EMAIL PROTECTED] with the word unsubscribe in the message body.
