30.07.2014, 07:18 PM
Hi to all, and excuse me for posting in English: it is much faster for me than using my poor command of the German language.
I see that you are discussing heaters - and while the idea I would like to propose might not seem directly connected to the discussion so far, I believe that parallels will soon emerge.
To cut a long story short, I would like to draw to your attention the possibility of using HF AC (high frequency AC) to heat tubes. This can be easily and cheaply done by modifying electronic transformers for halogen lights.
While a more extensive modification (still looks simple to me) in order to apply this solution to the heating of direct heated tubes (filamentary cathodes), it is even simpler to use it to heat indirect heated tubes.
I wrote about it on my blog:
http://rh-amps.blogspot.com/2014/06/rh81...oject.html
and intend to write more about it.
As far as tubes in general go, just imagine having to provide heating to something that requires 2x 10V 5A -- and as an added complication, you need to avoid hum (i.e. you will most probably have to opt for DC). Once you pile up all the equipment and parts necessary, and calculate the energy consumed, you can compare it with a small slightly modified electronic transformer that costs literally peanuts (I guess the cap needed might be more expensive than the unit itself).
On the indirect heated front, since hum is not an issue, an even simpler modification can provide 12.6V or 6.3V with as much current as you need.
Any opinions or previous experiences? Anyone willing to give it a try?
I see that you are discussing heaters - and while the idea I would like to propose might not seem directly connected to the discussion so far, I believe that parallels will soon emerge.
To cut a long story short, I would like to draw to your attention the possibility of using HF AC (high frequency AC) to heat tubes. This can be easily and cheaply done by modifying electronic transformers for halogen lights.
While a more extensive modification (still looks simple to me) in order to apply this solution to the heating of direct heated tubes (filamentary cathodes), it is even simpler to use it to heat indirect heated tubes.
I wrote about it on my blog:
http://rh-amps.blogspot.com/2014/06/rh81...oject.html
and intend to write more about it.
As far as tubes in general go, just imagine having to provide heating to something that requires 2x 10V 5A -- and as an added complication, you need to avoid hum (i.e. you will most probably have to opt for DC). Once you pile up all the equipment and parts necessary, and calculate the energy consumed, you can compare it with a small slightly modified electronic transformer that costs literally peanuts (I guess the cap needed might be more expensive than the unit itself).
On the indirect heated front, since hum is not an issue, an even simpler modification can provide 12.6V or 6.3V with as much current as you need.
Any opinions or previous experiences? Anyone willing to give it a try?