03-01-2014, 10:51 PM
Here we go again...
The next unit for the bench is a Fisher 440-T receiver I picked up recently. Here's a photo of it, from the eBay ad:
[Image: http://www.philcoradio.com/images/phorum...e00004.jpg]
Yup...pretty grungy. I'm hoping the front panel can be made to look decent, in spite of all of the numbers having been rubbed off around the volume knob, and the words "Volume" and "Tuning" nearly rubbed off. If I can get rid of the panel's overall dirty, grungy look (plus getting the knobs clean), I'll be satisfied.
It came in with a dead left channel, but a working right channel.
A look under the chassis:
[Image: http://www.philcoradio.com/images/phorum...e00003.jpg]
You will notice that the under-chassis layout is very similar to the Fisher 4400. The main difference between the two: The 440-T is all-silicon, whereas the 4400 uses germanium driver and output transistors.
I did some checking with my signal tracer, and found that the signal made it all the way to the 1500 uF coupling electrolytic between the left channel output transistors and the speaker - on the other side of this electrolytic, the signal was lost.
I also noticed that dry electrolyte was coming out of the ventilation holes in both output coupling electrolytics. In fact, several of the electrolytics looked as if they had seen better days.
So, this evening, I began replacing them.
I have only six more to go - plus that AC line bypass cap. But since I am getting close, I tried it out again a little while ago.
Success! We have audio in both channels now!
The right channel sounds a bit muddy compared to the left channel, but since I still have some more electrolytics to replace in the audio chain, I am hoping that replacing those will take care of that issue.
I'll find out tomorrow...
The next unit for the bench is a Fisher 440-T receiver I picked up recently. Here's a photo of it, from the eBay ad:
[Image: http://www.philcoradio.com/images/phorum...e00004.jpg]
Yup...pretty grungy. I'm hoping the front panel can be made to look decent, in spite of all of the numbers having been rubbed off around the volume knob, and the words "Volume" and "Tuning" nearly rubbed off. If I can get rid of the panel's overall dirty, grungy look (plus getting the knobs clean), I'll be satisfied.
It came in with a dead left channel, but a working right channel.
A look under the chassis:
[Image: http://www.philcoradio.com/images/phorum...e00003.jpg]
You will notice that the under-chassis layout is very similar to the Fisher 4400. The main difference between the two: The 440-T is all-silicon, whereas the 4400 uses germanium driver and output transistors.
I did some checking with my signal tracer, and found that the signal made it all the way to the 1500 uF coupling electrolytic between the left channel output transistors and the speaker - on the other side of this electrolytic, the signal was lost.
I also noticed that dry electrolyte was coming out of the ventilation holes in both output coupling electrolytics. In fact, several of the electrolytics looked as if they had seen better days.
So, this evening, I began replacing them.
I have only six more to go - plus that AC line bypass cap. But since I am getting close, I tried it out again a little while ago.
Success! We have audio in both channels now!
The right channel sounds a bit muddy compared to the left channel, but since I still have some more electrolytics to replace in the audio chain, I am hoping that replacing those will take care of that issue.
I'll find out tomorrow...
--
Ron Ramirez
Ferdinand IN