28-06-2017, 11:32 AM
You're never to old to learn!
Is this an AM radio or AM/FM?
I assume from your post that the radio is now working but not very well. Is that correct?
If so, it will often be possible to re-align it without any equipment at all, other than the correct trimming tools* and your own ears! This will be especially easy if it is AM only or if only the AM section needs attention.
* Never, ever, touch a dust iron/ferrite core with metal bladed screwdriver - particularly if it has a hexagonal hole or slit running all the way through it. You will crack the core and it will be jammed and very difficult to remove without damaging the coil former.
If you provide the model number, I'm sure someone will be able to identify exactly which tools you need and probably where/how to to obtain them.
The idea is essentially to use broadcast stations as your signal generator. Turn the volume up high and tune to a weakish station, then adjust the IF transformers for maximum volume, turning the radio so that the ferrite rod aerial progressively receives a weaker signal as the alignment improves the sensitivity (or change to a weaker station).
The reason for using the weakest possible signal is to prevent the set's AGC from obscuring the point of maximum sensitivity.
Once the IF has been adjusted, use known stations as close as possible to each end of the MW band to correctly align the local oscillator and aerial circuits.
FM alignment isn't quite as simple but shouldn't prove impossible and you will end up with the satisfaction of having successfully learned a new skill.
You certainly aren't the only pensioner on here - I'm 2 years older than you! - but I have to admit to this being a life long interest. However, 60 years ago I could only dream of one day having access to an accurate signal generator - unlike you, I didn't even have a multi-meter! - so the method I've outlined above was the only option I had - and it worked very well!
Is this an AM radio or AM/FM?
I assume from your post that the radio is now working but not very well. Is that correct?
If so, it will often be possible to re-align it without any equipment at all, other than the correct trimming tools* and your own ears! This will be especially easy if it is AM only or if only the AM section needs attention.
* Never, ever, touch a dust iron/ferrite core with metal bladed screwdriver - particularly if it has a hexagonal hole or slit running all the way through it. You will crack the core and it will be jammed and very difficult to remove without damaging the coil former.
If you provide the model number, I'm sure someone will be able to identify exactly which tools you need and probably where/how to to obtain them.
The idea is essentially to use broadcast stations as your signal generator. Turn the volume up high and tune to a weakish station, then adjust the IF transformers for maximum volume, turning the radio so that the ferrite rod aerial progressively receives a weaker signal as the alignment improves the sensitivity (or change to a weaker station).
The reason for using the weakest possible signal is to prevent the set's AGC from obscuring the point of maximum sensitivity.
Once the IF has been adjusted, use known stations as close as possible to each end of the MW band to correctly align the local oscillator and aerial circuits.
FM alignment isn't quite as simple but shouldn't prove impossible and you will end up with the satisfaction of having successfully learned a new skill.
You certainly aren't the only pensioner on here - I'm 2 years older than you! - but I have to admit to this being a life long interest. However, 60 years ago I could only dream of one day having access to an accurate signal generator - unlike you, I didn't even have a multi-meter! - so the method I've outlined above was the only option I had - and it worked very well!
