AMERICAN style Amplifier....
I always loved the "viewing windows" on US built BC and SW amplifiers.
There is something about the Glass Tube Magic...seeing the anodes glow dark red and flickering of purple/blue tint on glass envelopes in rythm of your CW or SSB (I mean stray electrons hitting the glass envelope, not the blue/white fog filling the whole envelope due to gassy tube) is just something you never ever get bored of.
Anyway, the designer of the beast is Jan OK2BNG. Currently it is low bands only PA, mostly just waiting to be re-designed to accomodate additional PSUs for G1 and G2 for higher efficiency. It is grounded grid, grid driven (g1+g2) and grounded cathode / supressor grid). It's acting like High mu triode. Four of them. RF Deck is built around four GU81m(s). Soviet Pentodes, actually largest serial production traansmittig pentode (by size) in SSSR.
Anode dissipation - 750W (1000W with add.cooling in ICAS)
Plate voltage - 3kV - 6kV
Plate curent - 1A
Cathode+filament = 12-14V / 10V - directly heated, thoriated thungsten.
Control grid diss. - 30W
Screen grid diss. - 120W!
So yes, getting a 1500W for contest, you get instant power on (no 3 mins.waiting) and you get ultra clean signal with massive margin. Around 40W is needed to get 1500W key down. 100W gives you over 3kW. There is headroom in drive also and 160-200W drive is possible.
Comments
Post a Comment