The power supply sounds FB...but the plate tuning capacitor on the Globe King is just marginal when you run the stock modulator power supply. Any components which have modulated B+ appearing on them would have to be upgraded...caps..the bandswitch etc.
Al VE3AJM W5OMR/Geoff wrote: > [EMAIL PROTECTED] wrote: > > >Hello to all . well have gotten around to trying to restore my king that was > >salvaged from a basement flood. the PS and Modulator are gone but the RF > >Deck is rehabbed and working great on caw with an out board globe vfo or > >xtal. > >The question now is will my new 2000vdc @600ma power supply be ok to power > >the > >modulator also? and was wondering about the modulator. I have a Stancor A3898 > > 300 watt vari match mod xformer and was wondering about Tubes I have a good > >supply of 813 (Triode connected) or 572b. what do youall think > > > How much current is the GK500C drawing in the final, on CW? > > If I understand the nomenclature correctly, the '500' would/should be > around 500w DC input to the final. With 2000v, that would put the > current around 250mA. > > I'd say you'll have plenty of current handling capacity at 600mA to > handle the modulator. > > I'm not that familiar with the "C" version... what are the modulators, > 811's? > > I found this old 'ad' on somewhere out there on the 'net... > > ----- > Globe King 500C: transmitter; Ad: JAN 58 QST; price $795.00 > wired; 540 watts AM, 540 watts CW, 540 watts SSB (with external > exciter); 160 thru 10 meters; bandswitching. RF Section: 6AG7 > crystal oscillator, 6146 buffer, 4-400A final, 12AU7 keyer, 6X5 > and 5Y3 low voltage rectifiers. Modulator: 6SJ7 speech > amplifier, 6AL5 compression rectifier, 6C5 amplifier, 6L6G > driver, push-pull 811A modulators, 5Y3 low voltage rectifier, > pair 816 high voltage rectifiers; Power Supply: 5U4G low > voltage rectifier, pair 866A high voltage rectifiers, 0A2 > voltage regulator, 6AU6 VFO, 6CB6 VFO buffer; shipping weight > 300 lbs. > ----- > > So, it's got a pair of 811A's. I read also, somewhere, that the > modulator deck had it's own power supply, that utilized a pair of 816 > mercury vapor rectifiers. > > Unless you've got a seperate Bias supply for the 811A's at 2kVDC, I'd > say it's probably a bit much B+ to run on 811's. 1500v in Class B is > about good, for zero bias. > > Yes, you'll have enough power supply with the 2kV @ 600mA, and the 811's > will take the B+, as long as you put some bias voltage on the cathodes. > An adjustable, well regulated bias supply between the 811A filament > transformer center tap and ground would be a good place for that. > > -- > Driving your AM Rig without a scope, > is like driving your car at night, without headlights. (K4KYV) > > -- > 73 = Best Regards, > -Geoff/W5OMR > > ______________________________________________________________ > AMRadio mailing list > Home: http://mailman.qth.net/mailman/listinfo/amradio > Help: http://mailman.qth.net/mmfaq.html > Post: mailto:[email protected] > AMfone Website: http://www.amfone.net > AM List Admin: Brian Sherrod/w5ami, Paul Courson/wa3vjb > > -- > No virus found in this incoming message. > Checked by AVG Free Edition. > Version: 7.1.394 / Virus Database: 268.9.9/382 - Release Date: 7/4/06
