Yaesu FT-101 HF Transceiver

Posted on Feb 6, 2014

The 6JS6C tube is a TV Deflection Tube, or `Sweep Tube`. Although not meant for transmitting, it exhibits sufficient performance for RF operation through 30 MHz. Each tube can dissipate 30 watts of plate power. The base is a 12-pin socket. There will come a time when the finals in your FT101E will need replacing. The FT-101 transceivers were origi

Yaesu FT-101 HF Transceiver
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nally equipped with 6JS6C tubes manufactured by NEC and Toshiba. Other manufacturers tube properties are slightly different from the original 6JS6C tubes. Therefore, a simple modification to the neutralization circuit must be made to the final section of the transceiver. The modification consists of replacing the fixed value 100 pf 1000 VDC mica capacitor with a 10 pf 1000 VDC mica capacitor. This capacitor, C125, is in series with the 10 pf variable neutralizing capacitor off of the plate circuit. If this modification has not already been completed on your rig, be sure to use a mica or silver mica of at least 1000 VDC. Do not substitute a different type because the heat in the final compartment will change the value, and your tubes will fail prematurely. Also, be very careful to keep all leads short and in exactly the same orientation as the original capacitor. Before re-neutralizing, open the variable neutralizing capacitor all the way to minimum engagement and follow the neutralizing instructions in the manual. While dipping the PLATE, remember to adjust the neutralizing capacitor for equal value meter reading "dips" (Ic meter position) on both sides of the peak when tuning the PLATE control. WARNING! You are tuning a capacitor in the High Voltage compartment, +600 Volts are present! Always use non-metallic tuning tools. After neutralization, reset the bias to 60ma with CARRIER and MIC settings at minimum. QST- The...

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