Well first of all Harry I am not familiar with the Webster Electric PA amp but 25 watts output is a little on the light side but is usable if you don't load the DX60 to more than 40-50 watts plate input power. You could probably use a 25 watt audio output XFMR rated of single ended use, so it would handle the DC from the final. I have used a 200 watt power XFMR from old television sets as a modulation XFMR. Use the HV Secondary as the final side (experiment as to whether using all of the secondary or one half) and input from the PA (16 ohm to 12V) or (500 ohm to 110V). Experimentation might be necessary. Basically, if the 6146 rig is 500V and 100ma it would require 25 watts at 353 V RMS (0.707 X 500) to modulate it. Find the transformation windings that give you the closest match to get this voltage output. Your 25 watt amp is capable of putting out 20 volts RMS into 16 ohms or about 14 volts into 8 ohms or 112 volts for 500 ohm line.
If you had more audio power available then your options would be more. If the power XFMR is about 360 volts either side of CT then use CT to one one side (half of the secondary) for the plate circuit and input 500 ohms to the 115 Volt AC of the primary. You will use the DX 60 in the CW mode and connect the HV secondary of the outboard matching XFMR so that the B+ for the final and the screen resistor connection point are together and their current has to pass thru the XFMR to work. Check with other diagrams of 6146 plate modulated rigs in the older handbooks and you will get the idea. Good Luck John, WA5BXO -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Harry Vaught Sent: Friday, March 17, 2006 7:13 AM To: Discussion of AM Radio Subject: Re: [AMRadio] Amplifier to use with my DX-60 Ok, tell me this: I have a DX-60A and a 25 watt P-P 6L6 Webster Electric PA amp with a large selection of output impedances. What would I have to do to plate modulate my DX-60? There are obviously greatly varying levels of knowledge out there, and mine is probably below median. Harry, KT4AE Maryville, Tennessee ______________________________________________________________ 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
