Cory,
I have a Gonset GSB201 linear amplifier (GG 4-572B) where I use it on 75 / 40 meters as an AM Linear. My GSB-201 only puts out about 800 - 900 watts key down depending on drive and line voltage. I use an AM exciter that can produce a clean 10 watt carrier, and this carrier if any stronger would over drive the linear on AM. I get a clean 150 watts carrier output with this setup with room for lots of upward modulation. I never had a SB-220 but these are nice rigs with lots of upgraded circuitry available from various places. Now consider my situation where much above 10 watts drive results in non-linearity as seen from a trapezoid pattern when 100% modulating the drive on AM. I'd bet that with a SB-220 all you need is 20 to 25 watts drive for 375 watts output. The Viking II cannot run down there unless you modify it so that the final amp, and modulator run off the low B+ (might be pretty extensive modification to make work right), or run at about 80-100 watts output, and insert a 6 DB pad between the Viking II output and SB-220 input. That might do the trick. Now for efficiency sake, AM linear is poor in that regard, but is capable of being extremely effective, and linear. You can also run the legal limit on AM and not worry about a big heavy modulation transformer. As a bonus winter is coming, and a little air moving past those 3-500Z's will certainly heat the shack! Regards, Jim -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Cory Hine Sent: Sunday, September 26, 2004 1:14 PM To: amradio@mailman.qth.net Subject: [AMRadio] WTB SB-220 Hey gang, I am looking for a Heathkit SB-220 to run about 300 watts on AM using the Viking II to drive it. Does anyone have a decent amp that they want to sell? I would like pics if possible. Thanks, Cory/AD5QP --------------------------------- Do you Yahoo!? vote.yahoo.com - Register online to vote today! ______________________________________________________________ AMRadio mailing list Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net --- Incoming mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.767 / Virus Database: 514 - Release Date: 9/21/2004 --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.767 / Virus Database: 514 - Release Date: 9/21/2004