Yaesu FT101E - UK Vintage Radio Repair and Restoration Discussion Forum

supremme · 23rd Nov 2012, 1:51 am

I recently bought a yaesu ft101e, which takes many years standing, I bought the steel mill that does not transmit. after opening the lids, and see that everything is more or less normal, decico connect and to my surprise the computer on, go on light vfo but clicks and a burning smell started coming out with some smoke, the team turned around and saw it burn 1K5/5W R40, C11 200pf/1kv also damaged. I put R40nueva with 2 series resistors 1k ceramic type +560 ohm / 5W also disconnecting the capacitor C11. c40 resistance heating still very fast. clicks are heard. Thanks

PeterRoberts · 30th Nov 2012, 9:01 am

Hi,

I would suggest that you try the Yahoo Group dedicated to the FT-101 for more guidance, but I can give you some pointers.

First of all, you must be aware that high voltages are present within the radio and that you must take the necessary precautions when working inside the radio.

The capacitors C11, C13, C125 and C131 are known to go leaky with age and may need replacing. If it were me, I would replace all these in any case.

Also check on the screen grid resistors on the driver, R5 & R37. You obviously have a fault in the driver/PA stages, and may even have internal short circuits in either of the PA valves or the driver.

I suggest that you remove the valves from the driver and PA and check these for any internal short circuits. Do not replace the valves until the voltages in the radio are as indicated (within a reasonable tolerance) to those in the service manual. If you don't have a copy of the service manual you can get one from the foxtango.org website.

Good luck,

Peter
G4DJB

James Duncan · 21st Dec 2012, 3:30 pm

Never apply power to any valved equipment that has been stored for a long time.the capacitors will just heat up and cause heavy load resulting in damage, at times even exploding, big mess!!
Always power up via a variac or at least with a couple of 40 watt light bulbs in series with the power, let things soak for a few hours, then soak through one lamp for another few hours.

The caps in your radio will have done the damage but if you had powered up taking precautions it is more than likley your radio would have been OK.
No problem, change the caps, replace burnt resistors and also follow the advice given on this site.

cheers
MM0HDW

23rd Nov 2012, 1:51 am	#1
supremme Retired Dormant Member Join Date: Nov 2012 Location: Alicante, España. Posts: 8	Yaesu FT101E I recently bought a yaesu ft101e, which takes many years standing, I bought the steel mill that does not transmit. after opening the lids, and see that everything is more or less normal, decico connect and to my surprise the computer on, go on light vfo but clicks and a burning smell started coming out with some smoke, the team turned around and saw it burn 1K5/5W R40, C11 200pf/1kv also damaged. I put R40nueva with 2 series resistors 1k ceramic type +560 ohm / 5W also disconnecting the capacitor C11. c40 resistance heating still very fast. clicks are heard. Thanks

30th Nov 2012, 9:01 am	#2
PeterRoberts Pentode Join Date: Dec 2011 Location: Camberley, Surrey, UK. Posts: 145	Re: Yaesu FT101E Hi, I would suggest that you try the Yahoo Group dedicated to the FT-101 for more guidance, but I can give you some pointers. First of all, you must be aware that high voltages are present within the radio and that you must take the necessary precautions when working inside the radio. The capacitors C11, C13, C125 and C131 are known to go leaky with age and may need replacing. If it were me, I would replace all these in any case. Also check on the screen grid resistors on the driver, R5 & R37. You obviously have a fault in the driver/PA stages, and may even have internal short circuits in either of the PA valves or the driver. I suggest that you remove the valves from the driver and PA and check these for any internal short circuits. Do not replace the valves until the voltages in the radio are as indicated (within a reasonable tolerance) to those in the service manual. If you don't have a copy of the service manual you can get one from the foxtango.org website. Good luck, Peter G4DJB

21st Dec 2012, 3:30 pm	#3
James Duncan Pentode Join Date: May 2010 Location: Wick, Scotland, UK. Posts: 227	Re: Yaesu FT101E Never apply power to any valved equipment that has been stored for a long time.the capacitors will just heat up and cause heavy load resulting in damage, at times even exploding, big mess!! Always power up via a variac or at least with a couple of 40 watt light bulbs in series with the power, let things soak for a few hours, then soak through one lamp for another few hours. The caps in your radio will have done the damage but if you had powered up taking precautions it is more than likley your radio would have been OK. No problem, change the caps, replace burnt resistors and also follow the advice given on this site. cheers MM0HDW