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Old 30th March 2013, 04:54 PM   #541
6L6 is offline 6L6  United States
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I have 2 transformers that could work - Which do you think would be better?

Both are not ideal - the potted one is a little shy on voltage, the Hammond has no filament CT...

I just noticed this about the potted one - if you look at the schematic, and the pins confirm it as well, the CT of the HV and the filament is the case... That's weird...

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Last edited by 6L6; 30th March 2013 at 04:59 PM.
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Old 30th March 2013, 05:03 PM   #542
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Top one has a case shield which is useful -- the Allied Transformer SY used Allied 6K3VG also had one.
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Old 30th March 2013, 05:21 PM   #543
6L6 is offline 6L6  United States
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Quote:
Originally Posted by jackinnj View Post
Top one has a case shield which is useful -- the Allied Transformer SY used Allied 6K3VG also had one.
And the fact that the CT of the HV and FIL windings is that same shield is no problem? I ask only because I haven't seen that before.
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Old 30th March 2013, 06:02 PM   #544
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If it's potted then there's be no way to disconnect it!

There are other ways to get the filament at the potential necessary.
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Old 21st May 2013, 09:57 PM   #545
6L6 is offline 6L6  United States
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Coming along nicely. More parts on order.

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Old 21st June 2013, 07:27 PM   #546
6L6 is offline 6L6  United States
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Im needing to make one more order to get all the parts...the local electronics surplus has most of the stuff, but I still need to fill it out.

A couple questions,

What voltage NE-2? I'm not sure if the ratings are the strike voltage or max operating...

Is there any issue using a stepped attenuator? I have a 100K noble that I'm planning on using, but I'm still curious...

Are there any 'gotchas' in building this? Anything not obvious?
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Old 21st June 2013, 07:30 PM   #547
SY is offline SY  United States
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Neon is not critical, it's just for start-up protection- the lower the voltage, the better.

Main thing is to keep the bodies of the grid and gate stoppers close to the grids and gates. Otherwise, it's a pretty easy build.
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And while they may not be as strong as apes, don't lock eyes with 'em, don't do it. Puts 'em on edge. They might go into berzerker mode; come at you like a whirling dervish, all fists and elbows.
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Old 21st June 2013, 07:34 PM   #548
6L6 is offline 6L6  United States
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Great!

Are the gridstoppers not in the ideal place on Jack's boards?
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Old 21st June 2013, 07:38 PM   #549
SY is offline SY  United States
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They could be closer, but I've built two of Jack's boards and they both worked perfectly. So I can't really complain.
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And while they may not be as strong as apes, don't lock eyes with 'em, don't do it. Puts 'em on edge. They might go into berzerker mode; come at you like a whirling dervish, all fists and elbows.
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Old 21st June 2013, 07:44 PM   #550
6L6 is offline 6L6  United States
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I have another question that I just cant get my head around...

When running a F4 as mono you get 50W from a single-ended connection, but 100W from a balanced. The Rails are not any higher, and you have the same amount of PSU, so how can you get a doubling of power?



I'm sure with a good explanation it will become obvious...
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