Thanks Phil. Only fly in the ointment is that a CCS won’t swing to twice the HT voltage and I need all the undistorted drive I can get, this being a two stage design, so anode chokes are the easiest and most obvious choice in this particular application.
New SE With Triode Mode KT120/150
- Cressy Snr
- Amstrad Tower of Power
- Posts: 10579
- Joined: Wed May 30, 2007 12:25 am
- Location: South Yorks.
#91 Re: New SE With Triode Mode KT120/15
Sgt. Baker started talkin’ with a Bullhorn in his hand.
- Cressy Snr
- Amstrad Tower of Power
- Posts: 10579
- Joined: Wed May 30, 2007 12:25 am
- Location: South Yorks.
#92 Re: New SE With Triode Mode KT120/150
Some decent progress since Saturday:
Top plate has been drilled and punched, valve sockets fitted and the volume pot has been mounted on a bracket underneath. The pot will be reached with a shaft extender (cue DTB) from the front panel, once the thing is built. The plate is braced in both directions on the underside. I’m not putting up with saggy iron; not this time.
Valve lineup looks great.
Top plate has been drilled and punched, valve sockets fitted and the volume pot has been mounted on a bracket underneath. The pot will be reached with a shaft extender (cue DTB) from the front panel, once the thing is built. The plate is braced in both directions on the underside. I’m not putting up with saggy iron; not this time.
Valve lineup looks great.
Sgt. Baker started talkin’ with a Bullhorn in his hand.
-
- Thermionic Monk Status
- Posts: 5643
- Joined: Thu May 24, 2007 11:22 am
- Location: People's Republic of South Yorkshire
#93 Re: New SE With Triode Mode KT120/150
What's the top plate material Steve, stainless steel? Looks great.
- Cressy Snr
- Amstrad Tower of Power
- Posts: 10579
- Joined: Wed May 30, 2007 12:25 am
- Location: South Yorks.
#94 Re: New SE With Triode Mode KT120/150
Nah, just common or garden aluminium I’m afraid.
Sgt. Baker started talkin’ with a Bullhorn in his hand.
-
- Thermionic Monk Status
- Posts: 5643
- Joined: Thu May 24, 2007 11:22 am
- Location: People's Republic of South Yorkshire
#95 Re: New SE With Triode Mode KT120/150
Wow, looks quite shiny. Just the standard finish or has it had a bit of a polish?
- Cressy Snr
- Amstrad Tower of Power
- Posts: 10579
- Joined: Wed May 30, 2007 12:25 am
- Location: South Yorks.
#96 Re: New SE With Triode Mode KT120/150
It’s polished ally, which was covered with a plastic film on the shiny side. Being ally, it’s going to dull from exposure to the air. Whether it keeps its finish will depend on whether occasional polishing is practicable once all the iron is fitted. I would have liked stainless, but it’s a complete b’stard to punch holes in and IME it attracts fingermarks like a magnet.
Sgt. Baker started talkin’ with a Bullhorn in his hand.
- Cressy Snr
- Amstrad Tower of Power
- Posts: 10579
- Joined: Wed May 30, 2007 12:25 am
- Location: South Yorks.
#97 Re: New SE With Triode Mode KT120/150
The globe MH4s will be heated with 4V of regulated DC from an old DIYHS, DHT filament module, running its AC input off the standard 6.3V heater winding on the mains transformer.
Sgt. Baker started talkin’ with a Bullhorn in his hand.
#98 Re: New SE With Triode Mode KT120/150
Nice work steve.. looks like it coming on well..
My latest discovery is dibond, the local surplus store has off cuts in for next to nowt.. white on one side plain alloy on the other, I've done a log store roof with it, and a couple of amp top plates, it's so easy to work..
Just treat it like wood, the alloy side polishes up beautifully or it looks good sprayed.
I've now got hold of some smaller anodized pieces that will make some great top plates with out the need to spray them.
My latest discovery is dibond, the local surplus store has off cuts in for next to nowt.. white on one side plain alloy on the other, I've done a log store roof with it, and a couple of amp top plates, it's so easy to work..
Just treat it like wood, the alloy side polishes up beautifully or it looks good sprayed.
I've now got hold of some smaller anodized pieces that will make some great top plates with out the need to spray them.
The tube manual is quite like a telephone book. The number of it perfect. It is useful to make it possible to speak with a girl. But we can't see her beautiful face from the telephone number
- pre65
- Amstrad Tower of Power
- Posts: 21399
- Joined: Wed Aug 22, 2007 11:13 pm
- Location: North Essex/Suffolk border.
#99 Re: New SE With Triode Mode KT120/150
Thanks for the tip Steve, I see they do two shades of blue, and glossy or mat.steve s wrote: ↑Mon Jul 06, 2020 11:13 pm
My latest discovery is dibond, the local surplus store has off cuts in for next to nowt.. white on one side plain alloy on the other, I've done a log store roof with it, and a couple of amp top plates, it's so easy to work..
Just treat it like wood, the alloy side polishes up beautifully or it looks good sprayed.
EDIT.
I've ordered an A4 size piece in ultramarine blue to evaluate. At worst I can use it as a clipboard.
The only thing necessary for the triumph of evil is for good men to do nothing.
Edmund Burke
G-Popz THE easy listening connoisseur. (Philip)
Edmund Burke
G-Popz THE easy listening connoisseur. (Philip)
#100 Re: New SE With Triode Mode KT120/150
Phil..pre65 wrote: ↑Mon Jul 06, 2020 11:33 pmsteve s wrote: ↑Mon Jul 06, 2020 11:13 pm
My latest discovery is dibond, the local surplus store has off cuts in for next to nowt.. white on one side plain alloy on the other, I've done a log store roof with it, and a couple of amp top plates, it's so easy to work..
Just treat it like wood, the alloy side polishes up beautifully or it looks good sprayed.
Thanks for the tip Steve, I see they do two shades of blue, and glossy or mat.
EDIT.
I've ordered an A4 size piece in ultramarine blue to evaluate. At worst I can use it as a clipboard.
It cuts nicely with a track saw, a hole saw goes through it like butter, very fine wet and dry, then polish up the edges. I've found enamal spray paint gives very nice finish on it too, and does not rub off like acrylic crap.. You will have a lovely clip board....
The tube manual is quite like a telephone book. The number of it perfect. It is useful to make it possible to speak with a girl. But we can't see her beautiful face from the telephone number
- Cressy Snr
- Amstrad Tower of Power
- Posts: 10579
- Joined: Wed May 30, 2007 12:25 am
- Location: South Yorks.
#101 Re: New SE With Triode Mode KT120/150
Why is it, that shortly after you strip the protective sheet off the finished side of your aluminium, you find that there are invariably, half a dozen fecking holes you forgot to drill, no matter how many times you thought you’d checked beforehand?
Sgt. Baker started talkin’ with a Bullhorn in his hand.
#102 Re: New SE With Triode Mode KT120/150
That's what masking tape is for steve
The tube manual is quite like a telephone book. The number of it perfect. It is useful to make it possible to speak with a girl. But we can't see her beautiful face from the telephone number
#103 Re: New SE With Triode Mode KT120/150
Just leave it on,Cressy Snr wrote: ↑Tue Jul 07, 2020 10:14 am Why is it, that shortly after you strip the protective sheet off the finished side of your aluminium, you find that there are invariably, half a dozen fecking holes you forgot to drill, no matter how many times you thought you’d checked beforehand?
Sorry, I couldn't resist!
- pre65
- Amstrad Tower of Power
- Posts: 21399
- Joined: Wed Aug 22, 2007 11:13 pm
- Location: North Essex/Suffolk border.
#104 Re: New SE With Triode Mode KT120/150
I purchased a length of plain white Fablon eons ago and I use it on aluminium to mark things out prior to cutting, drilling, filing (and bleeding) etc. Then peel off to reveal the full glory of the material.
Just make sure the aluminium is degreased thoroughly before applying.
Masking tape is good as well.
The only thing necessary for the triumph of evil is for good men to do nothing.
Edmund Burke
G-Popz THE easy listening connoisseur. (Philip)
Edmund Burke
G-Popz THE easy listening connoisseur. (Philip)
- Paul Barker
- Social Sevices have been notified
- Posts: 8978
- Joined: Mon May 21, 2007 9:42 pm
#105 Re: New SE With Triode Mode KT120/15
You can put a solid state ccs in series with the choke, the choke gives you the ac swing the ccs gives you better isolation and frequency response.Cressy Snr wrote: ↑Sat Jul 04, 2020 11:21 amThanks Phil. Only fly in the ointment is that a CCS won’t swing to twice the HT voltage and I need all the undistorted drive I can get, this being a two stage design, so anode chokes are the easiest and most obvious choice in this particular application.
"Two things are infinite, the universe and human stupidity, and I am not yet completely sure about the universe." – Albert Einstein