09-11-2017, 06:29 PM
(This post was last modified: 09-11-2017, 06:31 PM by Murphyv310.)
Hi.
Well we have a fully working radio.
In the end I decided to use the spare board I found today and swap out the IF transformer from the radio's board. It fortunately was the only one that was untouched, it would have been daft to swap two from the spare board to the sets own one.
I have replaced all three transistors in the donor board as the AF117's had tin whisker syndrome, I have also realigned the set as the tracking was well out, the MW oscillator trimmer was tightly screwed down and the slug in the oscillator coil was way above the can. I set up the the oscillator trimmer initially with it unscrewed three turns and then proceeded with aligning both to get correct tracking. Oddly enough the IF stages were just about spot on. Long wave has been a little bit more of an issue, both LW aerial and oscillator trimmers were way off and after getting the alignment right and adjusting the LW aerial coil position the results on Long Wave are a bit poor. I will have another look tomorrow before boxing up the set.
Once fully completed I'll give it a few days soak test and return it.
In the end I believe the two IF cans and some O/C print were the faults and of course tin whisker issues in the AF117's.
Well we have a fully working radio.
In the end I decided to use the spare board I found today and swap out the IF transformer from the radio's board. It fortunately was the only one that was untouched, it would have been daft to swap two from the spare board to the sets own one.
I have replaced all three transistors in the donor board as the AF117's had tin whisker syndrome, I have also realigned the set as the tracking was well out, the MW oscillator trimmer was tightly screwed down and the slug in the oscillator coil was way above the can. I set up the the oscillator trimmer initially with it unscrewed three turns and then proceeded with aligning both to get correct tracking. Oddly enough the IF stages were just about spot on. Long wave has been a little bit more of an issue, both LW aerial and oscillator trimmers were way off and after getting the alignment right and adjusting the LW aerial coil position the results on Long Wave are a bit poor. I will have another look tomorrow before boxing up the set.
Once fully completed I'll give it a few days soak test and return it.
In the end I believe the two IF cans and some O/C print were the faults and of course tin whisker issues in the AF117's.
