Re: Sears Farm Master Tractor Radio

Posted by Bus Driver on September 16, 2003 at 16:21:25 from (65.165.152.53):

In Reply to: Sears Farm Master Tractor Radio posted by Bill Becker on September 15, 2003 at 10:43:47:

Here is the little that I know about those 6 volt radios- speaking about them generically. The A voltage- for the tube filaments- was, of course, 6 volts. The B+ voltage was higher- maybe 115 or there abouts. The radio had a vibrator which made a sort of AC from the DC. The manufactured AC was put through a transformer for stepup, then rectified back to DC+. I think the vibrator made a full wave AC to minimize the hum in the speaker. My guess also is that the rectifier was also full wave. Lots of filter capacitors. Frequently, the rectifier tube was an OZ4, a gas filled, non-filament tube. That and the vibrator were the most troublesome parts of the radio. I think they would be the most difficult parts to find today. The use of the OZ4 lessened the current load by eliminating one filament and lessened the heat also. Those radios would get rather warm. Today, the vibrator probably could be replaced with a solid state circuit and the rectifier with ordinary diodes.

Follow Ups:

Post A Followup Name: E-Mail: Subject: Re: Re: Sears Farm Master Tractor Radio Comments: Optional Link URL: Link Title: Optional Image URL: Email Notification: If you check this box, email will be sent to you whenever someone replies to this message. Your email address must be entered above to receive notification. This notification will be cancelled automatically after 2 weeks.

TRACTOR PARTS	TRACTOR MANUALS

We sell tractor parts!  We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today. [ About Us ]