FT-857@groups.io | Low power output on SSB and CW

Low power output on SSB and CW

#857D

Alex, VE9WS Всі повідомлення цього користувача #54204 Hello group, I wonder if I get the ceramic filter problem on my FT-857D. TX power on FM looks good, I can see it draws 12-15 amps on the power supply. But on CW and SSB, it does not draw more than 4 amps, and the ALC does not kick in. Any suggestions? Thank you. Alex VE9WS
Ronald E Smith Всі повідомлення цього користувача #54205 Hi Alex. ALWAYS expect that the 455Khz TOKO Ceramic Filters are a problem. Always. If they have never been changed, change them. And be very careful changing them. They are not easy to get off. The ground plane on the 857 and 897 Main Units are a wicked Heatsink. You need good tools to do it. Not to mention all the very small components around them on the bottom side of the PCB. Then test again. It will most certainly have an effect and likely fix your issue. Ronnie VE3NLS Innovative Circuits Electronics Repair Centre #2040 30/31 Side Road West Oro-Medonte, Ontario L0L 2L0 E-mail ron@... Mobile 705-791-6634 From: <FT-857@groups.io> on behalf of "Alex, VE9WS via groups.io" <alex.ve9ws@...> Reply-To: <FT-857@groups.io> Date: Sunday, November 10, 2024 at 2:54 PM To: <FT-857@groups.io> Subject: [FT-857] Low power output on SSB and CW #857D Hello group, I wonder if I get the ceramic filter problem on my FT-857D. TX power on FM looks good, I can see it draws 12-15 amps on the power supply. But on CW and SSB, it does not draw more than 4 amps, and the ALC does not kick in. Any suggestions? Thank you. Alex VE9WS
J.D. Barron Всі повідомлення цього користувача #54206 I don't thank that there is a ceramic filter in the CW and SSB path. There is a crystal filter, but also there is an if AMP in there. I don't have the schematic nearby right now, but look at the path from the SSB filter to the down stream amp to the left.
Ronald E Smith Всі повідомлення цього користувача #54207 That is correct. My apologies. CF1004 is the Ceramic filter for SSB/CW. Thanks for the correction. Still if those 455 Khz filters are crusty looking they should be changed. And perhaps it could be the IF amp as stated or any one of those PIN diodes that select the mode. It is a pretty busy IF section. Ronnie VE3NLS Innovative Circuits Electronics Repair Centre #2040 30/31 Side Road West Oro-Medonte, Ontario L0L 2L0 E-mail ron@... Mobile 705-791-6634 From: <FT-857@groups.io> on behalf of "J.D. Barron via groups.io" <jeter.d.barron@...> Reply-To: <FT-857@groups.io> Date: Sunday, November 10, 2024 at 5:41 PM To: <FT-857@groups.io> Subject: Re: [FT-857] Low power output on SSB and CW #857D I don't thank that there is a ceramic filter in the CW and SSB path. There is a crystal filter, but also there is an if AMP in there. I don't have the schematic nearby right now, but look at the path from the SSB filter to the down stream amp to the left.
J.D. Barron Всі повідомлення цього користувача #54208 That is correct and they are really cheap from Yaesu. If you do change them don't be afraid of using a high wattage gun for those ground pins. I use a 140 watt Weller gun, but you have to be careful of the small nearby parts or remove them first. It is a fairly easy job of you are careful. Sometimes when working I cover and isolate nearby parts with some aluminum or Kapton tape to remind me to be careful.
J.D. Barron Всі повідомлення цього користувача #54209 Sorry to interrupt again, but you should use an oscilloscope to trace the signal path. Changing parts with no clear reason is just looking for problems in the dark.
Alex, VE9WS Всі повідомлення цього користувача #54210 Thank you! That confirms my thoughts. I initially thought of microphone not having enough gain. Tested with another mic and then CW both have the same results. I might send it to Yeasu to replace both CF1004 and CF1005(?) as I don't have a high wattage gun, or worth of an investment. 73, Alex VE9WS
Ronald E Smith Всі повідомлення цього користувача #54211 Don’t spend that kind of money on it Alex. The shipping there and back plus the US exchange is nuts. Give me a call. I repair these all the time. And I apologize to the moderator if this is out of line. Ronnie VE3NLS Innovative Circuits Electronics Repair Centre #2040 30/31 Side Road West Oro-Medonte, Ontario L0L 2L0 E-mail ron@... Mobile 705-791-6634 From: <FT-857@groups.io> on behalf of "Alex, VE9WS via groups.io" <alex.ve9ws@...> Reply-To: <FT-857@groups.io> Date: Sunday, November 10, 2024 at 8:41 PM To: <FT-857@groups.io> Subject: Re: [FT-857] Low power output on SSB and CW #857D Thank you! That confirms my thoughts. I initially thought of microphone not having enough gain. Tested with another mic and then CW both have the same results. I might send it to Yeasu to replace both CF1004 and CF1005(?) as I don't have a high wattage gun, or worth of an investment. 73, Alex VE9WS

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