DIYbanter - View Single Post - Why should someone replace ALL the capacitors on old Tube equipment?

Michael Black[_2_]

On Wed, 8 Feb 2017, wrote:

On Tue, 7 Feb 2017 16:11:28 -0500, Michael Black wrote:

There are stories of Collins receivers, I forget which model, where the
capacitor feeding the mechanical filter can go bad, and the result is
a ruined mechanical filter, it can't handle the DC going through it.

SO that's the sort of thing knowledge that is out there for people coming
to an old receiver for the first time.

Michael

What is a " mechanical filter"?

It provide selectivity in the receiver. It goes in the IF, at 455KHz or
sometimes 500KHz or even I have one at 250KHz. Generally for narrow
selctivity, like for SSB or CW. Kind of expensive, but even more so
decades later when they are no longer being made, and finding a specific
model may not be so easy. So if the capacitor goes, it can be expensive
to remedy.

Michael