Search found 20199 matches

by Mike H
Tue Oct 07, 2008 9:16 pm
Forum: Everyones Projects
Topic: 300b filament module
Replies: 26
Views: 20414

1,400V @ 350mA? http://livinginthepast-audioweb.co.uk/images/misc/huh.gif   Strewth... Hold on chaps, it just happens that the TX has four 5V windings on it. I'm sure you could equally as well use 12V. Just needs a bit more 'padding out' http://livinginthepast-audioweb.co.uk/images/misc/smile.gif
by Mike H
Tue Oct 07, 2008 9:08 pm
Forum: New Users
Topic: Hi All
Replies: 59
Views: 36530

Hold on, wot 'appened 'ere? Image


Oh the ol' Jota, once saw it described as "one of the last great hairy chested creatures of our age" Image
by Mike H
Tue Oct 07, 2008 6:05 pm
Forum: Everyones Projects
Topic: 300b filament module
Replies: 26
Views: 20414

I'm having them made? Image
by Mike H
Tue Oct 07, 2008 5:50 pm
Forum: Beginners
Topic: Parafeed Conversion
Replies: 17
Views: 13199

I'm getting confused again, what's the advantage of a parafeed over a SE transformer?

Image
by Mike H
Tue Oct 07, 2008 4:40 pm
Forum: Valves
Topic: ECL82 Grid stopper resistor value?
Replies: 16
Views: 14579

Hi Dave, thanks for that, yes very interesting! (NB goes on a bit dunnit?) Yes I saw yer early cct and thought 'eek, motor-boating'; like the 1st time I turned on me wireless amp is wot it did ~ needed to decouple the HT for the 1st stage. No like you said a perfect way to learn about it I reckon, o...
by Mike H
Tue Oct 07, 2008 3:26 pm
Forum: Everyones Projects
Topic: 300b filament module
Replies: 26
Views: 20414

DC 300B heater supply

What do you reckon on this idea?

Duncan's designer says 20mV peak-peak of ripple at the filament (R1). I should mention the '6 Ohms' would need to be made up by padding resistors as necessary
by Mike H
Tue Oct 07, 2008 3:05 pm
Forum: Valves
Topic: ECL82 Grid stopper resistor value?
Replies: 16
Views: 14579

Re: ECL82 Grid stopper resistor value?

That's what I call a breadboard ~ btw is/was that a real breadboard?
Dave the bass wrote:I've got a 1M grid leak, what value grid stopper could I fit to stop him from whistling like a crazy whistling machine when he has no i/p?
According to the old Dansette record player cct, 10k. And the grid leak is 470k. :)
by Mike H
Tue Oct 07, 2008 2:54 pm
Forum: New Users
Topic: Hi All
Replies: 59
Views: 36530

Re: SA Capacitors

No worries ... :D I have just asked Mike for a price for SA capacitors for the 6 in the WD25T V2 crossover - Still waiting ~ also should warn you if we do get them from ICW direct there's typically a lead time of 4 - 6 weeks ~ AFTER they get the money. They don't keep a stock in a warehouse, they st...
by Mike H
Mon Oct 06, 2008 8:26 pm
Forum: Assorted Stuff
Topic: Resistors
Replies: 7
Views: 16371

Re: Resistors + Arcol Carbon Comp?

I've just noticed (don't know why only just) these Arcol carbon comp 0.25 & 0.5W resistors; anybody know anything about them? I.e. if they're any good I know it makes a difference to the sound changing from CF to MF. But has any of you guys done a direct A-B comparison between brands? Yes I did!...
by Mike H
Mon Oct 06, 2008 4:08 pm
Forum: New Users
Topic: Hi All
Replies: 59
Views: 36530

Aw thanks Dave, yes did work for Maplin's for quite a while, mostly used to write their catalogue and they also had a magazine that I did editing and stuff. Not all by myself of course
by Mike H
Mon Oct 06, 2008 12:02 am
Forum: New Users
Topic: Hi All
Replies: 59
Views: 36530

That was my fault, I uploaded a bunch of stuff and they went in the wrong place! Working now
by Mike H
Sun Oct 05, 2008 9:24 pm
Forum: New Users
Topic: Hi All
Replies: 59
Views: 36530

Oh very good!

How about a 22 + a 4.7 ?

Oh that's interesting, the SA's don't usually come smaller than 1uF
by Mike H
Sun Oct 05, 2008 8:03 pm
Forum: Valves
Topic: pentode question
Replies: 21
Views: 14383

g3 on the 12GN7 is a internal shield as well, at least it is on pin 3, so shouldn't that be connected to ground? So it is ~ actually both 3 and 9 ~ okay so they're assuming the cathode is going to be decoupled. (Or yes, g3 is earthed, but only for video/RF usage.) However it's such low impedance at...
by Mike H
Sun Oct 05, 2008 2:38 pm
Forum: Valves
Topic: pentode question
Replies: 21
Views: 14383

Okay well assuming 4k as per drawing, with 32000 umhos and Ri of 60k, I'm getting X120. So 360V?

Incidentally 12HG7 also comes up as NJ7P.

Plus cos it's one o' them radio/video tubes, a grid stopper is highly recommended.
by Mike H
Sun Oct 05, 2008 1:55 pm
Forum: Valves
Topic: pentode question
Replies: 21
Views: 14383

with regard to the suppressor, I originally took PB's advice when I was messing with my EL34 and G3 to ground sounded much better than G3 to K, it was a chalk and cheese thing......... Oh really? As an aside, if anybody is still reading this thread....I can't find any refs to amp factor for the 12h...