tag:blogger.com,1999:blog-5462678272949384534.post5710848698647861773..comments2023-10-16T16:24:51.773+01:00Comments on Ham Radio Ireland - EI2KC: A problem with my Watson W-25AM power supplyAnthony Murphyhttp://www.blogger.com/profile/01840266019811924856noreply@blogger.comBlogger7125tag:blogger.com,1999:blog-5462678272949384534.post-72269708948758366582016-04-13T15:15:03.114+01:002016-04-13T15:15:03.114+01:00I am looking for the black screw thing that holds ...I am looking for the black screw thing that holds a wire on to the post of my W-25AM. Any idea where I can get one?Anonymoushttps://www.blogger.com/profile/08481204723381331105noreply@blogger.comtag:blogger.com,1999:blog-5462678272949384534.post-84424614240525236482011-03-02T19:56:07.845+00:002011-03-02T19:56:07.845+00:00Hi check capacitor C6 on PCB board.
It is connecte...Hi check capacitor C6 on PCB board.<br />It is connected to 5th and 6th leg of lm324. this part of op-amp is looking after current limit level.<br />for test you can remove diode D3 but the current limiter will no longer work. Incrising value of this cap should sort your problem.<br />Just in case don't test this with radio use car head lamp bulb as load.Anonymoushttps://www.blogger.com/profile/10722982829652379668noreply@blogger.comtag:blogger.com,1999:blog-5462678272949384534.post-71454170757930917512010-09-08T20:09:26.564+01:002010-09-08T20:09:26.564+01:00Ok Anthony, I hope the problem can be fixed. I don...Ok Anthony, I hope the problem can be fixed. I don't know how this supply is regulated, but from the size I think it is not a switching one. So I think then one of the final transistors broke.<br />I guess the other ham has experience with it. Good luck...<br />73, BasPE4BAS, Bashttps://www.blogger.com/profile/12958141238330445285noreply@blogger.comtag:blogger.com,1999:blog-5462678272949384534.post-79126756699538294982010-09-08T08:42:57.088+01:002010-09-08T08:42:57.088+01:00Bas, the power supply is doing this in the shack o...Bas, the power supply is doing this in the shack of another ham who took it away to look at it. It is broken I think. It was not connected to the ground system. I have the FT-1000MP, FT-897 and the MFJ-941E tuner all connected to ground but they are connected to each other too. The Watson PSU was never connected to ground. I had it away from the shack last night and the problem was still happening.HamRadioIrelandhttps://www.blogger.com/profile/11008583900692977974noreply@blogger.comtag:blogger.com,1999:blog-5462678272949384534.post-26840888062525951582010-09-08T08:24:57.470+01:002010-09-08T08:24:57.470+01:00Hi Anthony, this is either a RFI problem or you go...Hi Anthony, this is either a RFI problem or you got a earthloop somewere. Did you connect everything with separate wires to your ground connection? So if you did, try to remove them one for one to see if it makes any difference. I did have the same problem <a href="http://pe4bas.blogspot.com/2010/09/cleaning-up-shack.html" rel="nofollow"> you can read it here</a>. Although I don't have meters on my supply my radio switched of at a certain amount of power (SSB). Good luck, 73, BasPE4BAS, Bashttps://www.blogger.com/profile/12958141238330445285noreply@blogger.comtag:blogger.com,1999:blog-5462678272949384534.post-59445337234225258042010-09-07T22:51:52.810+01:002010-09-07T22:51:52.810+01:00Paul, I was using SSB on HF and giving a whistle. ...Paul, I was using SSB on HF and giving a whistle. This problem happens even with just one radio connected. The current draw varies according to the RF power selected on the radio. The PSU was working fine and one day my 2m FM rig started to switch off as I was talking and then I noticed the voltage dropping.HamRadioIrelandhttps://www.blogger.com/profile/11008583900692977974noreply@blogger.comtag:blogger.com,1999:blog-5462678272949384534.post-8556313565153692542010-09-07T22:41:39.547+01:002010-09-07T22:41:39.547+01:00Hi Anthony, it looks like a heavy current draw is ...Hi Anthony, it looks like a heavy current draw is causing the voltage drop - A 100w radio draws about 20 amps on FM, what is the current draw on the supplies ammeter when you key up ?Paul M0PCZhttps://www.blogger.com/profile/15826957754325181436noreply@blogger.com