Farnell FG1 Function Generator. - UK Vintage Radio Repair and Restoration Discussion Forum

theredhouseinn · 6th Sep 2022, 9:29 am

Diodes went s/c and burnt out the mains tx.
I have repaired the former and rewound with new wire.
Now the difficult bit, how to clean off the pitch and varnish from the lams.
I have tried petrol, parrafin, white spirit, acetone, and in the ultrasonic cleaner at 70 degees, but none will shift the crud.
Has anyone successfully cleaned lams without damaging them?
John.

Diabolical Artificer · 7th Sep 2022, 5:46 am

I used a low heat oven, petrol and elbow grease to good effect in the past. Have also used Nitromorse, luckily had some old formula stuff.

Andy.

theredhouseinn · 10th Sep 2022, 4:50 pm

Thanks Andy.
The old memory needs a jog sometimes, I have a can of nitromorse in the cupboard.
I soaked the lams in it for 24 hours, brushed them off in water with a tooth brush, soaked them in wd40 for a day, got all the lams back in except for a damaged one when I took them out.
Stuck the mains on it, 22 volts spot on.
John.

6th Sep 2022, 9:29 am	#1
theredhouseinn Hexode Join Date: Jan 2013 Location: Kelvedon, Essex, UK. Posts: 273	Farnell FG1 Function Generator. Diodes went s/c and burnt out the mains tx. I have repaired the former and rewound with new wire. Now the difficult bit, how to clean off the pitch and varnish from the lams. I have tried petrol, parrafin, white spirit, acetone, and in the ultrasonic cleaner at 70 degees, but none will shift the crud. Has anyone successfully cleaned lams without damaging them? John.

7th Sep 2022, 5:46 am	#2
Diabolical Artificer Dekatron Join Date: Jul 2009 Location: Sleaford, Lincs. UK. Posts: 7,669	Re: Farnell FG1 Function Generator. I used a low heat oven, petrol and elbow grease to good effect in the past. Have also used Nitromorse, luckily had some old formula stuff. Andy. __________________ Curiosity hasn't killed this cat...so far.

10th Sep 2022, 4:50 pm	#3
theredhouseinn Hexode Join Date: Jan 2013 Location: Kelvedon, Essex, UK. Posts: 273	Re: Farnell FG1 Function Generator. Thanks Andy. The old memory needs a jog sometimes, I have a can of nitromorse in the cupboard. I soaked the lams in it for 24 hours, brushed them off in water with a tooth brush, soaked them in wd40 for a day, got all the lams back in except for a damaged one when I took them out. Stuck the mains on it, 22 volts spot on. John.