JI1FGX/DU9 Amateur Radio Diary, Mindanao, Philippines, IOTA OC-130.
English. Japanese.



Yesterday's access.
Introduction. [Lily Diary.
A diary of life in Mindanao.

   
25/07/13  IARU HF Contest
25/07/10 Software updates
25/07/08 DXV500ZS linear amplifier repair
25/07/07 CQ Machine Program
25/06/21 LoTW system upgrade
25/06/18 RG8 for 3.5MHz arrived
25/06/15  Time setting Ver0.5
25/06/14 Drone Habsan ZINO arrives
25/06/12 Philippine Independence Day
25/06/11 Algeria 7X2RF QSL card.
25/06/10 Translation API Program
25/06/09 DXCC150 award certificate arrived
25/06/08 AutoCWType_Ver1.4.1
25/06/07 Introducing the Shack
25/06/06 A portrait drawn by ChatGPT.
25/05/26 Windows full-width/half-width switching.
25/05/17 OK2ZAW BCD to 16 converter.
25/05/16 For 3.5MHz Zepp antenna.
Stepping motors
25/05/15 3.5MHz stepping motor design.
25/05/14 3.5MHz tuning coil installed.
25/05/11 3.5MHz antenna installation completed.
25/05/03 JTDX Autonomous Driving Program Ver0.4.3.
25/04/26 Drone Habsan ZINO.
25/04/25 Time setting Ver0.3.
25/04/24 AutoCWType_Ver1.3.
25/04/23 Preparing for FTDX3000 LCD repair.
25/04/22 Installation plan for 3.5MHz Zepp antenna.
25/04/21 AutoCWType_Ver1.1.
25/04/20 10,14MHz antenna installation completed.
25/04/19 JTDX Autonomous Driving Program Ver0.4.1.
25/04/19 14MHz antenna pole installed.
25/04/18 ThinkPad X390 repair completed.
25/04/17 Search is now possible.
25/04/15 Preparing the 10MHz dipole.
25/04/12 Hexbeam Part8.
25/04/06 My ThinkPad X390 is broken.
25/04/05. Time setting program.
25/03/31 JTDX Autonomous Driving Program.
25/03/30 Automatic log sending from CWType to Hamlog.
25/03/21 Hexbeam Part 7.
25/03/20 FreeDV Part 3 First QSO.
25/03/18 FreeDV Part 2 QSO in the shack.
25/03/16 Hexbeam Part 6.
25/03/15 Install FreeDV Part1.
25/03/09 Hexbeam Part5.
25/03/07 Hexbeam Part 4.
25/03/05 28MHz antenna modification
25/03/01 FTDX3000 is broken!
25/02/28 Pileup at 50MHz FT8.
25/02/28 DXV500ZS linear amplifier repair.
25/02/27 Tower pipe rebuilding plan.
25/02/26 Direction to Japan from Ozamiz.
25/02/26 28MHz is not available.
25/02/23 DXV500ZS linear amplifier repair.
25/02/22 Hexbeam Part 3
25/02/21 Hexbeam Part 2
25/02/18 28MHz antenna construction.
25/02/17 18,24MHz antenna height construction.
25/02/16 Z26NS Cosovo.
25/02/14 21MHz FT8
25/02/12 7,21MHz antenna repair.
25/02/08 Operating CW at 21MHz.
25/02/05 DXV500ZS linear amplifier failure.
25/01/19 Input Director.
25/01/14 Temporary license renewal.
DXV500ZS linear amplifier repair in Samway (2025/02/23) 
Diary for February 05, 2025but
Samway's DXV500ZS linear amplifier is smoking and won't turn on!
The fuse is not blown, but one cement resistor is heating red when the switch is left ON.
I emailed Mr. Ohashi at Samway.
He diagnosed a broken 100 ohm cement resistor, a bad relay, and probably a bad FET in Q1!

It was shipped via EMS on February 6 and arrived on February 21. This is still early.
Arrived parts

Relay RY1 G2R-1 DC12V 1 piece
Resistors R4,5 Cement 100Ω 5W 2 pcs.
FET Q1 2N7000 1 piece
Parts Total
EMS Shipping
660 yen
$352
$132
1,144 yen
1,900 Yen
I had trouble removing the relay.
And the Chinese-made desoldering wire you can buy at mail-order stores in the Philippines doesn't suck it up at all.
Pump-type desoldering equipment is not powerful enough

So I had no choice but to destroy the relay and remove the terminals.
 
As expected, one of the two cement resistors was broken.
The FETs are interchangeable 2N7000 and the arrangement of the legs is different, so this is what it looks like
2N7000 is a new part
S (source) is in the same position, but G (gate) and D (drain) are in different positions.
  
I'm not sure if I'm getting presbyopia lately, but I can't see the small FET letters.
I sent an email to Mr. Ohashi to see if the wiring of the compatible FET legs is correct, so I won't be able to energize it until Monday!
February 22, 2024   February 26, 2025