Search found 20199 matches

by Mike H
Fri Mar 29, 2024 9:57 pm
Forum: Everyones Projects
Topic: OK…so I’m on wi’ summat
Replies: 195
Views: 47883

Re: OK…so I’m on wi’ summat

Been a bit of a saga - I was just going to mention, but you changed it - the fading away thumping noise on switch off suggests low frequency oscillation. But not sure how. Could have been the PSU doing weird things, and amplified by the o/p stages. Just guessing.
by Mike H
Fri Mar 29, 2024 9:52 pm
Forum: Assorted Stuff
Topic: Nothing In Particular
Replies: 16520
Views: 4898010

Re: Nothing In Particular

Sorry about that Phil. :(

simon wrote: Fri Mar 29, 2024 9:30 pm Happy 70th Mike! Hope you've had a good day.
Thanks very much. I have champagne and chocolate cake, so pretty good. :lol:
by Mike H
Fri Mar 29, 2024 9:50 pm
Forum: Assorted Stuff
Topic: The Audio-Talk Motorcycling thread.
Replies: 1460
Views: 605713

Re: The Audio-Talk Motorcycling thread.

You noticed! :lol:

Actually it was a couple of days ago, I'm only writing it up now. :D
by Mike H
Fri Mar 29, 2024 9:39 pm
Forum: Assorted Stuff
Topic: The Audio-Talk Motorcycling thread.
Replies: 1460
Views: 605713

Re: The Audio-Talk Motorcycling thread.

The stator pole ends are pretty beat up, and the inside of the rotor has score marks. Going by my previous experience with my old D3, this indicates that the left crank main bearing had 'collapsed', allowing the crank end to 'whip', which in turn allowed the rotor and stator to come into contact. Bu...
by Mike H
Fri Mar 29, 2024 9:29 pm
Forum: Assorted Stuff
Topic: The Audio-Talk Motorcycling thread.
Replies: 1460
Views: 605713

Re: The Audio-Talk Motorcycling thread.

I have flitted like a butterfly onto Bantam stuff, if possibly briefly... Decided it would be easier to start working on the engine in the conservatory, the shed is too cramped, too dark, too cold in winter and too hot in summer (mind you the two latter are also true of the conservatory, but it wins...
by Mike H
Fri Mar 29, 2024 8:31 pm
Forum: Assorted Stuff
Topic: Nothing In Particular
Replies: 16520
Views: 4898010

Re: Nothing In Particular

Only just seen this, very sorry Phil. :(
by Mike H
Thu Mar 21, 2024 9:04 pm
Forum: News
Topic: Steve Harley death: Cockney Rebel singer dies at 73
Replies: 1
Views: 956

Re: Steve Harley death: Cockney Rebel singer dies at 73

Only just seen this, damn. :(
by Mike H
Sat Mar 16, 2024 10:08 pm
Forum: Everyones Projects
Topic: OK…so I’m on wi’ summat
Replies: 195
Views: 47883

Re: OK…so I’m on wi’ summat

Absolutely fab. :thumbright:
by Mike H
Sat Mar 16, 2024 10:04 pm
Forum: Solid State
Topic: Germanium Amplifier
Replies: 162
Views: 86569

Re: Germanium Amplifier

With improved output transistor biasing - originally thermistors were added for safety, they basically went across the transformer secondaries, because the DC resistances of same formed part of the resistor divider that biases each o/p transistor, as per the Burns-Orbit. The original thermistors are...
by Mike H
Sat Mar 16, 2024 8:06 pm
Forum: Assorted Stuff
Topic: Owston 2024?
Replies: 5
Views: 876

Re: Owston 2024?

I am also interested. Almost guaranteed MCRU would be as well. :D
by Mike H
Sat Mar 16, 2024 8:04 pm
Forum: Assorted Stuff
Topic: General health matters.
Replies: 794
Views: 213629

Re: General health matters.

Ah the pressure tester thing! It is impossible not to blink.
:D
by Mike H
Sat Mar 16, 2024 3:36 pm
Forum: Solid State
Topic: Germanium Amplifier
Replies: 162
Views: 86569

Re: Germanium Amplifier

First 30 seconds of a WAV file - Life Is A Long Song by Jethro Tull..... :D - Germanium amp 2024-C4-wav.png - I had the EP of this when it first came out, so 1971-ish, ad often used it as a 'test signal' for whatever I was building at the time. Not an ideal choice to be honest, and caused a bit of h...
by Mike H
Sat Mar 16, 2024 3:29 pm
Forum: Solid State
Topic: Germanium Amplifier
Replies: 162
Views: 86569

Re: Germanium Amplifier

Frequency sweep, checks out OK...
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Germanium amp 2024-C4-noise.png
Germanium amp 2024-C4-noise.png (9.99 KiB) Viewed 1995 times
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Noise plot, it is what it is...
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Germanium amp 2024-C4 f-sweep.png
Germanium amp 2024-C4 f-sweep.png (9.09 KiB) Viewed 1995 times
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Clipping with 2V peak input. No unexpected behaviour...
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Germanium amp 2024-C4-clip 2V.png
Germanium amp 2024-C4-clip 2V.png (12.23 KiB) Viewed 1995 times
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by Mike H
Sat Mar 16, 2024 3:25 pm
Forum: Solid State
Topic: Germanium Amplifier
Replies: 162
Views: 86569

Re: Germanium Amplifier

Alright, so then I found this fabulous thing - it's another one from the school exercise book... this is Fig 10.38 from the original library book... - Fig1028.jpg - They are taking the NFB back to the driver stage emitter, so I tried that... first I did what you suggested, take it back to base, that...
by Mike H
Sat Mar 16, 2024 3:13 pm
Forum: Solid State
Topic: Germanium Amplifier
Replies: 162
Views: 86569

Re: Germanium Amplifier

Definitely got that going on hasn't it? This is a bit too new, let's go with what we know ... :lol: