AR88 curious voltages - Page 2 - UK Vintage Radio Repair and Restoration Discussion Forum

cendoubleu · 9th Jan 2009, 8:14 pm

Thanks Jim that makes it a lot more clear now. Trouble is I covered electronic theory 30+ years ago but haven't really used it for the last 25 so I'm a bit rusty!
As regards voltages, I use a DMM so input resistance is probably 10M ohms so that would make a difference. I hadn't appreciated that the input resistance of older meters was that low, having used an AVO 30 years ago which was 20,000.
I fixed the tone control problem last night. Just a dry joint on the tone pot, so thatw as an easy one! If I get time this weekend, I shall be changing the remaining bathtub caps and then can investigate the BFO prob.
Thanks everyone for all your help and interest it is much appreciated

9th Jan 2009, 8:14 pm	#21
cendoubleu Tetrode Join Date: Jan 2007 Location: Lincoln, Lincs. UK. Posts: 94	Re: AR88 curious voltages Thanks Jim that makes it a lot more clear now. Trouble is I covered electronic theory 30+ years ago but haven't really used it for the last 25 so I'm a bit rusty! As regards voltages, I use a DMM so input resistance is probably 10M ohms so that would make a difference. I hadn't appreciated that the input resistance of older meters was that low, having used an AVO 30 years ago which was 20,000. I fixed the tone control problem last night. Just a dry joint on the tone pot, so thatw as an easy one! If I get time this weekend, I shall be changing the remaining bathtub caps and then can investigate the BFO prob. Thanks everyone for all your help and interest it is much appreciated