The peak voltages are an issue, but more of a problem is the duty cycle. Running 300 watts carrier with 1200 watts pep has a much higher duty cycle then 2000 watts pep in ssb service. I think even 100 watts of AM has more of a duty cycle then 2000 watts pep ssb.
I gave up a long time ago on traps and baluns, coils are ok, like the butternut vertical, or loading coils on a dipole, but any cap needs to be something like 10 or 20 kv to hold up. While running experimental antennas through an antenna tuner, I have had the rg214 get HOT, set fire to the balun in the heatkit antenna tuner, etc. I am trying to come up with a multiband antenna that will fit my lot (100 feet between trees), and the only thing that would work well at my power levels would be open wire line into a balanced antenna tuner. A tuner to handle my power would be huge, with massive coils that would be hard to make out of copper tubing, very large caps and switches, etc... I found a very good design in an old arrl handbook, 1966 I think, but its LARGE and states its good for 500 watts of AM I think, or maybe less. The other idea is a G5RV, with very little coax between the balanced line and the tuner, and careful tuning of the length. I might be able to put a G5RV up next to the 40 meter dipole and test its operation.. Brett N2DTS > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of Ed Sieb > Sent: Friday, December 29, 2006 8:48 AM > To: Discussion of AM Radio in the Amateur Service > Subject: RE: [AMRadio] Thank You and Toroidal transformers > > Yup, I zapped and zorched a "300 Watt" antenna tuner with my > DX-100! 100W > of well modulated AM equals 400W PEP! More if your running over 100% > positive peaks! 125% positive=500WPEP! Few small tuners will > handle that, > and a TH3Jr or TA33Jr tri-bander certainly won't! > > Ed, VA3ES > ------------------------------------------------------ > > > Brett gazdzinski wrote: > My guess is the hardline will work fine without > any matching, most Pi nets will match it fine. > I also don't like toroids or baluns on AM, > high power (or even medium power) AM tends to overload > and/or cook anything like traps or baluns in short order. > Many antennas rated for 2kw plus pep crap out with 100 > watts of AM on them.... > I blew out traps in a trapped dipole and in a vertical > antenna with a DX100 (100 watts out). > > > ______________________________________________________________ > AMRadio mailing list > List Home: http://mailman.qth.net/mailman/listinfo/amradio > Partner Website: http://www.amfone.net > Help: http://mailman.qth.net/mmfaq.html > Post: mailto:[email protected] > ______________________________________________________________ AMRadio mailing list List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:[email protected]
