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Yaesu FT-101EE

Radio Tech

Radio Operator
Sep 9, 2008
858
309
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North Carolina
www.gokarters.com
Ant one have any good quality pictures of the bottom side of this rig?
Or have a rig torn down at the moment?

Had one come into the shop today with the final tubes removed. one was cracked. He had took it to another tech that just started pulling stuff out and he stopped him. There was a burnt component under the tube socket that has been removed. By looking at the two pieces I can not tell if it was a resistor or a diode let along just where it was mounted at.

Oh, has anyone ever replaced the 6JS6 with 6KD6? My info says they are the same.
 

I couldn't find my cross referance so I just compared the specs of both tubes. They are very similar in specs and should be interchangable. In fact the 6KD6 has 33 watts plate dissapation compared to the 6JS6's 30 watts. The 6KD6 makes a nice litte RF amp tube. When I was still in school I built a small amp using a pair of them and ran an easy 100 watts on SSB with it.
 
Garth, how do you think the 6LB6 compares to the 6JS6C ? I was told by someone they have used this tube as a direct substitute.
 
My old Sylvania tube manual shows them to be quite compatable,in fact they have the exact same pin-outs. the 6KD6 has the pin 9 to consider as I mentioned above. I would at least try either the 6KD6 or the 6LB6 but do it in pairs. NEVER mix tube types.
 
There has been quite a few discussions on Tube subs for the 101, I would suggest Googling the subject before making any decisions on the matter. I will say from experience, because the tube us listed as a sub does not mean it will work well in a particular circuit.
 
There has been quite a few discussions on Tube subs for the 101, I would suggest Googling the subject before making any decisions on the matter. I will say from experience, because the tube us listed as a sub does not mean it will work well in a particular circuit.


That's why I look at the individual tube specs and compare them rather than rely on a simple yes/no answer regarding subs.
 
That's why I look at the individual tube specs and compare them rather than rely on a simple yes/no answer regarding subs.

Even when you do this it is not enough with this radio, it just does not work well with any tubes that spec close/the same..

The 101 can be a crapper, and it IS worth a little Research before changing the tubes for it.
 
When changing to an American tube from the original Japanese tubes there has to be a modification done to the neutralizing circuit .

There will come a time when the finals in your FT101E will need replacing. The FT-101 transceivers were originally 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.

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.
http://www.qsl.net/nw2m/ft101.html
 
This is another comment from RFParts-

[FONT=Verdana, Arial, Helvetica, sans-serif]Notes:
(a) When replacing Japanese 6JS6C tubes in FT-101 transceivers with U.S. brand, it is necessary to replace the 100 pF series feedback capacitor with a 10 pF / 1KV dipped mica cap or two 20 pF mica caps in series (equaling 10 pF / 1 KV) before neutralizing.
(Note: Total series feedback capacitance of 10-20 pF is acceptable.)
[/FONT]
Read This Before Installing Tubes
 
QRN, I saw the pin 9 difference. I was thinking that it would not be a problem since the Yaesu has this pin socket open. There is nothing connected to it. I just checked the one tube that is not cracked and it shows 90 percent with no shorts. So going to look around and see if I can find another to match it.



EDIT
After going through a box of NOS tubes I picked up a few months ago I found three 6JS6. They check good so tube is not a problem now.



Still trying to track down the missing component.
 
Last edited:
Yes thats common knowledge, was a factory service bulletin regarding the cap change... You'll have to dig a bit deeper for the discussion on various sweep tubes as replacements for the 6JS6.. Even the swap for 6146 tubes can be problematic..

Yeah, I've heard a lot of problems changing over to that tube.I personally would probably stick with the 6js6c tube and cap change if the originals were not available.
 

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