If you can't get out consistantly with a Viking II, you need an antenna - not an amp. bob...w2ami www.qrz.com/callsign/w2ami
----- Original Message ----- From: "Gary Blau" <[EMAIL PROTECTED]> To: "Discussion of AM Radio" <[email protected]> Sent: Sunday, September 26, 2004 9:22 PM Subject: Re: [AMRadio] WTB SB-220 > I've always found more RF power, at least in significant iterations of > ~100watts, can make a big difference on the air in cutting thru noise > and band conditions. But what's more important is full modulation. > > One potential benefit of running a -modified- Viking or Ranger, etc. > into an amp like the SB220 is you can then concentrate on improving the > modulation performance of the exciter xmtr. This can in turn deliver a > more effectively modulated signal thru the entire system and thereby on > the air. > Add that to the increased power ability of running a fully modulated > ~400 watts carrier, and a case can be made that this is one of the > easiest ways to get a big AM signal on the air. > The easiest is to use a rice box for an exciter, but that's another fist > fight. > > The Viking would have to be modified a good bit to optimize this > approach. The first problem being reducing the RF output to the 10-25 > watt level that the SB220 will want to see. I've never had a VikingII, > so I can't say for sure, but my first thought is to try a variable PA > screen voltage scheme. (I did this to good effect in my Ranger.) You'd > probably have to remove one of the 6146's in the Viking, and make other > changes as well, but the idea is that not only will you be able to vary > the drive to the amp, but it will also give the huge benefit of much > higher positive peak modulation capability. Positive peaks can easily > go way beyond 100% as the PA now is operating well below its peak > dissipation point. Even if you're not a believer in hugely asymmetrical > 'supermodulation', having an xmtr that can easily handle it will still > be a big improvement over the 'stock' Viking. > > Loudness is where it's at to get thru on a noisy band, but having an > extra 100-200watts as well makes a potent combo. > > g > > > [EMAIL PROTECTED] wrote: > > > > << I am looking for a Heathkit SB-220 to run about 300 watts on AM using the > > Viking II to drive it. >> > > > > Hi, > > > > If you are getting the full output from the V II into a good well matched > > antenna, a couple of hundred more watts is not going to make any significant > > difference on the receive end and will only serve to heat up the shack and run up > > your power bill. > > > > 73, > > > > John, W4AWM > > ______________________________________________________________ > AMRadio mailing list > Home: http://mailman.qth.net/mailman/listinfo/amradio > Help: http://mailman.qth.net/mmfaq.html > Post: mailto:[email protected] >
