[R-390] Filter repairs

[Graham Baxter]

Hi all,

Thank you for your kind comments and supportive feedback. I think I am
now happy with the latest version of the filter repair article. So,
major spelling mistakes excepted, you can consider it stable.

The latest version is at:

http://www.delphelectronics.co.uk/filter390a/

Please refresh your browser and see what you think.

If anyone has a proper R390A site and would like to host this, please
let me know. I am a bit limited for space.

Would you believe I had a third faulty filter? I had not noticed this
before because although faulty, the only symptom was blow-by
manifesting itself as twittering noises on SSB. I didn't replace the
coils in this one, just a good clean, new foam and a new earth strap
cured it. I have taken the opportunity to add a couple more photos
courtesy of this filter.

Take care

Graham