开云体育

ctrl + shift + ? for shortcuts
© 2025 开云体育
  1. Yaesu-FT-101
  2. Messages
Single Messages Topics Expanded Polls

Re: FT-101e ALC issue

 

Hi Buddy,
VR2 on the processor board seems fine. I did find several cold solder joints on the processor board that was causing erratic alc readings when trying to adjust VR2 and also very low output power with the processor turned on. I ended up re-soldering the entire processor board which solved those problems. I've recapped the power supply p.c.b. and replaced the two diodes in the alc circuit underneath the finals. I replaced a bad electrolytic on the screen grid of the driver tube. I've checked every component with my modern component testers and I'm hitting a brick wall now.

This was an ebay buy that a local ham purchased. I do a lot of repairs on all sorts of radios for the local guys. I had to do a lot of studying on this radio and am aware of the cb crowd. I would guess that this one was used for the 11m band.? lol.? I'm going to try to keep plugging away today on it. I'll try messing around with the alc control on the processor board again.

Thank you for your reply Buddy. Have a good day.
Bob Dostall
Senior Technician
Vasu Communications


On Mon, Jun 7, 2021 at 11:44 PM kc4umo <buddymclawhorn@...> wrote:

Hi Bob,

Interesting problem.? And with full output I do not think the finals would cause that but I have seen strange things before.

Really does sound like something in the ALC circuit. Have you checked the ALC control itself?? I have seen those become intermitted before.

?

With that in note I have also seen wiring issues that gives false ALC readings. Remember these were used by many cb’ers.

I will pull the notes and see what I can find in the next day or so.? Really sounds like something simple.

?

Buddy

?

From: [email protected] <[email protected]> On Behalf Of bobd@...
Sent: Monday, June 7, 2021 11:29 AM
To: [email protected]
Subject: [Yaesu-FT-101] FT-101e ALC issue

?

I've been troubleshooting an FT-101e with an ALC issue. I get full power out at all times. After about 10 minutes of warmup, the alc fails to deflect much to the left. It works great for a few a minutes. I've checked and replaced as needed all of the components in the alc circuit that feed to the processor board.
I disconnected the white wire that feeds the processor board and my -1.2v steadily drops to about -.3v.
I don't know where else to look. Would gassy finals cause this? Even though I still get full output power?
Any help would be greatly appreciated.
Bob KF8IY

Join [email protected] to automatically receive all group messages.