From: cd6699@notformail.com   
      
   On Sat, 06 Dec 2025 14:29:43 +0000, Cursitor Doom   
    wrote:   
      
   >On Mon, 01 Dec 2025 08:01:18 -0500, legg  wrote:   
   >   
   >>On Sun, 30 Nov 2025 18:07:46 +0000, Cursitor Doom   
   >> wrote:   
   >>   
   >>>On Sun, 30 Nov 2025 12:41:35 -0500, legg  wrote:   
   >>>   
   >>>>On Sun, 30 Nov 2025 14:38:33 +0000, Cursitor Doom   
   >>>> wrote:   
   >>>>   
   >>>>>Here are the photos of the suspicous resistor; let me know what you   
   >>>>>think. In addition to the blow holes, it's also slightly mis-shapen.   
   >>>>>   
   >>>>>https://disk.yandex.com/d/ommuYJD2ZKsW8A   
   >>>>   
   >>>>Doesn't look like a paint defect, nnless you've been poking   
   >>>>at it with an exacto knife tip, after the fact.   
   >>>   
   >>>I've not been excavating! There was a bubble on the surface   
   >>>originally, which I scraped off with a fingernail to reveal that hole.   
   >>>I didn't dig any further.   
   >>>   
   >>>>Can't tell if it's smoke or just bad shadowing. Why not same   
   >>>>exposure and lighting in all three images?   
   >>>   
   >>>It was very difficult to photograph, because the depth of field was   
   >>>close to zero and the resistor was only millimeters from the lens   
   >>>glass. I had to use a hand-held LED lamp for illumination, but   
   >>>full-on, frontal illumination wasn't possible due to the proximity of   
   >>>the subject to the lens, I'm afraid. The lighting varies because I was   
   >>>holding the lamp by hand each time.   
   >>   
   >>A 'bubble' is a definite sign of a paint defect at time of mfr..   
   >>   
   >   
   >I've never come across that before; just assumed it had blown through   
   >over-current. I was *convinced* I was really on to something. I   
   >suppose I could excavate the hole out and see how far down it goes   
   >down. I might do that tomorrow just out of idle curiosity.   
      
   Well, before I got around to that, my Ferrograph, which had just got   
   back from a *very* expensive refurb, presented with the exact same   
   problem: zero recording to tape despite plenty of audio input. Since   
   the F'graph was still under warranty from the servicing people, I   
   called them up and complained (politely - fortunately, as it   
   happened). The chap on the phone said, "have you been playing old   
   tapes on it?" I said, "Yes." He said, "Give the heads a good clean,   
   then." I said, "They don't look dirty." He said, "Give 'em a good   
   clean anyway and see if that fixes it." So I did (not having any faith   
   it would help in the least, however). Nevertheless, full recording was   
   instantly restored! So I thought I'd try the same thing with the Uher   
   - and despite the heads looking perfectly clean, that worked too!   
   It's been nearly 50 years since I last used reel to reel tapes and it   
   seems I'd forgotten a basic piece of regular maintenance and that was   
   the cause of my problem. I'd spent *hours* going through all the   
   circuitry looking for anomalous voltage readings and finding none,   
   squirting test signals into the amp chain and not finding any red   
   flags there, not to mention the bias oscillator and the AGC. Whilst   
   all the time, the solution was a simple bit of housework.   
   Back in the day, we didn't need to worry about oxide-shedding, but old   
   tapes age the same as we do, it transpires; some worse than others.   
   Ampex are the *worst* in this respect, I've learned. Don't play old   
   Ampex. Don't buy NOS Ampex. Google "sticky shed" for more info and   
   don't fall into the same rabbit hole I did!   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)