Hello, I have a nice SB 220 with two brand new matched Machlet 3-500zg's. I have done the following to the amplifier.
Direct grounded the Grids, New Harbach Soft Start, Harbach HV metering board, and replaced the capacitors with 500v, 390Mfd computer grade units. The bleeder resistor are now 51k ohm flameproof resistors. They bleed to 0 volt in about 40 seconds and stay significantly cooler than the stock units.
I have a dozen or so pictures to document the rebuild and show how everything was taken apart and cleaned. 100 watts input equals 1500 out. 3300v on the plate with little sag and minimal grid current/plate current.
The only issue, is the Load knob is craked where it attaches to the shaft and it wobbles a little bit. I will also include a partial built W7RY QSK board and parts to complete the unit. The input SWR like most heathkits is around 2.1:1. I just use the internal tuner in my radio. A cheap external tuner would work as well. I would prefer Local pickup and Demo, but will ship at buyers expense. I am willing to drive a short distance, 100 miles or so to help.
$950 obo $650 no tubes
I am selling my trusty Kenwood TS-480HX. The radio has never been mobile. I installed the VGS1 and performed a Mars Modification. The radio has always received excellent audio reports. Radio comes with all manuals shown, mic, Both power cords and cables. The only issue I know of, Every so often, I would have to unplug the mic from the radio and plug it back in. The radio would tx but with low audio. I cleaned the RJ connector, and that helped but didnt totally solve the issue. The mic connector may need to be replaced eventually.
Price $875 Shipped Conus
Direct grounded the Grids, New Harbach Soft Start, Harbach HV metering board, and replaced the capacitors with 500v, 390Mfd computer grade units. The bleeder resistor are now 51k ohm flameproof resistors. They bleed to 0 volt in about 40 seconds and stay significantly cooler than the stock units.
I have a dozen or so pictures to document the rebuild and show how everything was taken apart and cleaned. 100 watts input equals 1500 out. 3300v on the plate with little sag and minimal grid current/plate current.
The only issue, is the Load knob is craked where it attaches to the shaft and it wobbles a little bit. I will also include a partial built W7RY QSK board and parts to complete the unit. The input SWR like most heathkits is around 2.1:1. I just use the internal tuner in my radio. A cheap external tuner would work as well. I would prefer Local pickup and Demo, but will ship at buyers expense. I am willing to drive a short distance, 100 miles or so to help.
$950 obo $650 no tubes
I am selling my trusty Kenwood TS-480HX. The radio has never been mobile. I installed the VGS1 and performed a Mars Modification. The radio has always received excellent audio reports. Radio comes with all manuals shown, mic, Both power cords and cables. The only issue I know of, Every so often, I would have to unplug the mic from the radio and plug it back in. The radio would tx but with low audio. I cleaned the RJ connector, and that helped but didnt totally solve the issue. The mic connector may need to be replaced eventually.
Price $875 Shipped Conus
