Hello everyone,
I have a push pull 813 amp with 1.3kva DC on the plates, 700VDC on G2.
I went from using a lead acid AGM 12 Volt battery for the filament supply (which sounded fantastic) , to a bridge rectifier ->68,000uf cap -> filaments - the noise (hum) was horrible.
Should I try a dc to dc converter?
Or CLC ?
Or Something else?
Cheers
I have a push pull 813 amp with 1.3kva DC on the plates, 700VDC on G2.
I went from using a lead acid AGM 12 Volt battery for the filament supply (which sounded fantastic) , to a bridge rectifier ->68,000uf cap -> filaments - the noise (hum) was horrible.
Should I try a dc to dc converter?
Or CLC ?
Or Something else?
Cheers
1.) Is filament AC grounded?
2.) Each 813 filament requires individual 10V, 5A power. It's for one hour 50Ah.
Working it for 4 hour the required capacity more than 200Ah.
12V 230Ah Victron AGM accumulator dimensions 532x220x207mm.... for one tube. :-(
BTW each large chemical accumulator is noise generator more or less.
I would use appropriate transformer, then bridge and smoothing.
p.s. In my Volvo diesel car the AGM accu only 96Ah. 🙂
2.) Each 813 filament requires individual 10V, 5A power. It's for one hour 50Ah.
Working it for 4 hour the required capacity more than 200Ah.
12V 230Ah Victron AGM accumulator dimensions 532x220x207mm.... for one tube. :-(
BTW each large chemical accumulator is noise generator more or less.
I would use appropriate transformer, then bridge and smoothing.
p.s. In my Volvo diesel car the AGM accu only 96Ah. 🙂
You at least need a CLC, but realistically you will need a lot more filtering than that.
You should really look at a rod coleman dht heating kit.
You should really look at a rod coleman dht heating kit.
I think you mean watt hour, not amp hour.
A 96 amp hour battery could keep an 813 running for about 19 hours. A 96 watt hour battery could only keep it running for less than 2 hours.
Buy two 5v switching power supplies and connect them in series for 10v. Add some 100uH chokes and maybe 1000uF of filtering and you will have a dead quiet supply.
Or get a 12V switcher and add the filtering. Mouser/Digikey carry them for a wide variety of voltages and currents. You do need to be careful with putting too much cap on a switcher output. They have limits as to how much they can drive.
Just add a low drop regulator, if you want to really do it right acquire a low drop current source (Tentlabs). Beware of switchers as many of them generate HF junk and noise. Not something you want to inject into your cathodes. I tried 813 P-P with AC using a hum-pot as a virtual cathode (pure and simple) but eventually moved ti regulated DC. Can't get AC quiet with these tubes. Other than that, they are fantastic (in triode anyway)
Yea, in triode they are beautiful.
In pentode , with separate supplies for plate and G2, rectifaction via SemiQ SiC schotty diodes, OS G.E. PIO caps , an oil choke for G2, oil transformer for G2, and an AGM battery on the filaments, fixed bias, GOSS plasticless (craft paper) OPT, they are outstanding.
In pentode , with separate supplies for plate and G2, rectifaction via SemiQ SiC schotty diodes, OS G.E. PIO caps , an oil choke for G2, oil transformer for G2, and an AGM battery on the filaments, fixed bias, GOSS plasticless (craft paper) OPT, they are outstanding.
Last edited: