We all hate intermittent problems. I'd much prefer a "dead" set to troubleshoot.

Is there a logical way to troubleshoot pops, say that occur once every 2-3 minutes or so? The only thing I've tried is to pull out tubes, one by one, and try to pinpoint the stage where the pop is originating. Still, a pretty crude approach.

I'm talking about after recapping, jiggling connections, etc.

Well, after you recap a set, you're left with IF transformers (and possibly other transformers), tube sockets, tubes, and wiring, and, of course resistors...possibly the volume control, especially if worn or if sprayed with WD-40. Not sure which one you should start with. Depending on the set, sometimes all can cause terrible problems (for instance, corroded silver on silver micas, causing a poor connection within the IF transformer....rocking the transformer makes and breaks the connection, causing the transformer to go into and out of resonance). Certainly it would probably be logical to start with one category and then work over to another, or perhaps one stage, and then work onto another. Either way could prove to be quite satisfactory.

T.

Doug, Sometimes use a 0.1uf/630V polyester cap as a AC grounding probe. Easy to make, connect one lead to B- and the other lead to the probe for grounding out various points in the radio such as IF transformers, resistors, tube pins, etc. With patience and a little luck you can work out which stage is making the noise.

Richard

Interesting suggestion, Richard. I'd probably use aligator clips for the 0.1-uF cap to keep it hooked up for a while, while waiting to see if the pops are eliminated.

:Doug, Sometimes use a 0.1uf/630V polyester cap as a AC grounding probe. Easy to make, connect one lead to B- and the other lead to the probe for grounding out various points in the radio such as IF transformers, resistors, tube pins, etc. With patience and a little luck you can work out which stage is making the noise.
:
:Richard

One thing to look for is a broken/cracked resistor. Turn off the lights and work in the dark. You should see something.

Bill VA

:We all hate intermittent problems. I'd much prefer a "dead" set to troubleshoot.
:
:Is there a logical way to troubleshoot pops, say that occur once every 2-3 minutes or so? The only thing I've tried is to pull out tubes, one by one, and try to pinpoint the stage where the pop is originating. Still, a pretty crude approach.

When and how do these "pop" manifest themselves??
Do they occour only while tuning? or while adjusting volume?
Does it make pops all by itself just sitting there?
Do the pops occur only on certain stations or at one end of the band?
Do external events exaccerbate the problem...like switching lights on or off?

Do a little logical analysis first and perhaps the solution will float to the top... lol

Doug,
With no other supporting info/symptoms, I'll just make a few WAGS. First the pop would indicate a discharge of energy somewhere, but what precedes or follows? A lights out look-see at the tubes could easily pin-point an arc-over in one of them. Even after re-capping, you could still have a bad one. As an example, today I measured 5 new caps (Sprague Orange drops) 0.0047mfd that were 0.0067mfd.
Did you test the caps on an instrument that provides the higher operating voltages of tube type radios or a unit like mine with a 9 volt battery? Some newer caps are so called self-healing, and I assume this is a feature that would heal a rupture thru the dielectric between the plates. What if the rupture re-occurs at regular intervals and repairs itself magically? Could even be something as simple as a bad socket or single filament breaking contact inside a tube, then re-connecting and welding itself again. I have observed incandescent bulbs do this for months before finally failing to re-weld.

marv

:We all hate intermittent problems. I'd much prefer a "dead" set to troubleshoot.
:
:Is there a logical way to troubleshoot pops, say that occur once every 2-3 minutes or so? The only thing I've tried is to pull out tubes, one by one, and try to pinpoint the stage where the pop is originating. Still, a pretty crude approach.