02-15-2011, 08:08 PM
Hi Robert,
I know how 'life' can take priority, and our hobbies can cate a back seat. That's ok though. I never take the hobby as a race to finish something. Also there is a chance to make a mistake. Seen it before with some 'new hobbiests'.
Taking your time will make for a better job in the end, and you will learn as you go.
You are doing the right thing, examining the chassis, comparing to the schematic, identifying parts, connections, and the stages of the total circuit. You don't need to be an engineer, or know the precise way the set works. Just basics for now.
The solder joints sure are larger compared to today's SMT parts.
The loud hum you described is symptomatic of failed filter caps. Those are the larger valued caps in the power supply section. Generally, there are 2, maybe 3 in some cases. Replacing those first, should get rid of the hum, and you may even receive stations at that point. Powereing down, you now know that the rest of the circuit is working, the coils and tuning section is working, the audio section is working because you can hear the stations.
Next, replacing the paper caps should make the set perform even better.
The chassis mounts on the cornes (?) are available as reproduction. Those old ones get dry and crack.
Attaching a good power cord would be a good start. Try to verify every wire that you cut
is correct, so that there is no question they are right.
If in doubt, the diagram will show you the way.
Examine the rubber wiring, for now, if they aren;tflaking and not touching, you may be able to leave them in place for the moment. When you are doing your paper caps, is usually a good time to do those.
You bought an Argus 75? The old TLR ? I should have a couple of those around here.
As for the tuntable speed, you could look for a more modern unit to install. I doubt any kind of voltage reduction would work right making the motor go slower.
Will check back later.
Gary.
I know how 'life' can take priority, and our hobbies can cate a back seat. That's ok though. I never take the hobby as a race to finish something. Also there is a chance to make a mistake. Seen it before with some 'new hobbiests'.
Taking your time will make for a better job in the end, and you will learn as you go.
You are doing the right thing, examining the chassis, comparing to the schematic, identifying parts, connections, and the stages of the total circuit. You don't need to be an engineer, or know the precise way the set works. Just basics for now.
The solder joints sure are larger compared to today's SMT parts.
The loud hum you described is symptomatic of failed filter caps. Those are the larger valued caps in the power supply section. Generally, there are 2, maybe 3 in some cases. Replacing those first, should get rid of the hum, and you may even receive stations at that point. Powereing down, you now know that the rest of the circuit is working, the coils and tuning section is working, the audio section is working because you can hear the stations.
Next, replacing the paper caps should make the set perform even better.
The chassis mounts on the cornes (?) are available as reproduction. Those old ones get dry and crack.
Attaching a good power cord would be a good start. Try to verify every wire that you cut
is correct, so that there is no question they are right.If in doubt, the diagram will show you the way.
Examine the rubber wiring, for now, if they aren;tflaking and not touching, you may be able to leave them in place for the moment. When you are doing your paper caps, is usually a good time to do those.
You bought an Argus 75? The old TLR ? I should have a couple of those around here.
As for the tuntable speed, you could look for a more modern unit to install. I doubt any kind of voltage reduction would work right making the motor go slower.
Will check back later.
Gary.
