Most big power amps, used in Amateur radio are still Valve, especialy in VHF, my prefered frequencies.
Transformers v power supplies.
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sparky230 said:
Very much depends on what you call a big power amp. I have two that could easily punch out well over a K each. Multi stage and not a bottle in sight. Damn great cooling fans though. Still have a couple of working bottle based HF rigs too, but not used much nowadays. Interesting that they are still playing with valves for the modern RAE though.
Russian G7's quite popular still for Hf, Lot of Vhf Amps still about using 4cx250's or 4xc350's.
Yes the MRF series of transistors now getting popular for High Power amps
Yes the Full Exam includes Valves,http://www.brats-qth.org/training/advanced/index.htm
Yes the MRF series of transistors now getting popular for High Power amps
Yes the Full Exam includes Valves,http://www.brats-qth.org/training/advanced/index.htm
This might explain switch modes a bit better, hope not too technical
http://www.learnabout-electronics.org/PSU/psu30.php
http://www.learnabout-electronics.org/PSU/psu30.php
And the 'youngsters' think blue LED's are 'cool'!sparky230 said:
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At college, we had a film club, and one of these sat on the landing outside the projection room.. Only way out for projectionist was to walk past it!! 'Elf and safety would never allow that now..
This is an interesting topic. I say bring back Mercury Arc Rectifiers - I saw one used on the Manx electric and it looked like dante's inferno. You used to be able to see the one at the Crich tram musem in a lttle shed half way down the line. On the modelling front, one of those arc welder flashy thinks in a shed would do nicely.
Anyway, Chief Simpleton here, about to incur the wrath of wiser men. Having read and inwardly digested I offer the following cheap generalisation of an SMPS.
A device which takes sinusoidal AC and converts it to a high frequency PWM square wave signal before rectifying it to DC and removing any residual ripple.
:-X
Anyway, Chief Simpleton here, about to incur the wrath of wiser men. Having read and inwardly digested I offer the following cheap generalisation of an SMPS.
A device which takes sinusoidal AC and converts it to a high frequency PWM square wave signal before rectifying it to DC and removing any residual ripple.
:-X
Yep, Thanks! I just about kept up with that. i had to take the link to 'mark and space variations' which was useful.sparky230 said:
Blinking heck - I think I am getting this.
Cheers guys.
If you are looking for a Switch mode Power Supply I think Mean Well SE-350W Single Output Switching Power Supply are the best. i.e. SE-350-24. 24 Volts 14.6 Amps.
I used to use them in my medical days. as they also do a medical range.
Do not get confused with cheap Chinese versions.
I used to use them in my medical days. as they also do a medical range.
Do not get confused with cheap Chinese versions.