Garey and Ron Thanks for the additional info on bias setting. I still have the cover off the T4 and the AC4 so I need to continure with the meter calibration/bias setting. The T4 seems to be working well except the output is a bit low. I am seeing 110W out on 80 and 40M at this point. The meter is reading low now so I need to get a more permanant 2.2ohm (i.e. higher wattage) and set the R38 value after setting the bias to the proper level. I have a DMM and an old Heath V-6a to measure with as well as a HV probe for the V6.
Anybody remember the value of the AC3 TP resistor (s)? What is the best way to determine R38 value? With 110 watts out I am only measuring a bit over .2 amps on the meter. No load plate V in the AC4 is 704V so that is ok and regulation seems to be within limits. .2 X 700 is 140 W and with 70% that should give 98Watts. Well that is in the ball park I guess to what I am measuring but is efficiency really that high? I will put it on the 'real' dummy load (i.e. Heath Cantenna) and try again. I did work a Virginia Beach station on 75 for about 40 min with only a wire out the window with a decent report though and seemed to be working well (185) miles or so at 9pm local time. Put a pix of the bad shunt resistor and the T4 on the blog yesterday. Paul K3PG Paul Gerhardt K3PG http://pgerhardt.blogspot.com QRP ARCI 6674 FP 274 _______________________________________________ Drakelist mailing list [email protected] http://mailman.zerobeat.net/mailman/listinfo/drakelist
