[Amps] Not the Diacrode

[John Lyles]

The Diacrode is a decent high power UHF tube, it is a double-ended tetrode, but it has the same transit time effects as a similar "bottom" circuited tetrode. It merely allows placement in the center of a resonant circuit instead of
at the end, placing a more favorable portion of the voltage standing wave across the active length of the anode/screen region. It does improve on most of the other factors discussed that limit high power at high frequencies, such as 
lead inductance and screen dissipation. I am working with one of these tubes at present, a TH628. Try Googling this part number. 

73
John 
K5PRO

> > This discussion would not be complete without mention of 
> > tubes which actually take advantage of the transit time 
> > effect - TWT's (Traveling Wave Tubes) and Klystrons. There 
> > may be others too. I haven't kept up with recent technology 
> > in this area.
> 
> Add to the list the Klystrode (r) or Inductive Output Tube 
> (IOT) and the Diacrode.  There may be other devices that 
> combine multiple technologies - like the multi stage depressed 
> collector IOT (MSDC IOT) - but it's been a few years since I 
> last worked with the high power UHF devices. 

>    ... Joe, W4TV