AVO 8 Mk 5 - UK Vintage Radio Repair and Restoration Discussion Forum

Andrewausfa · 24th Dec 2017, 6:35 pm

I picked this one up recently for a not a lot and going over it this afternoon found it's reading low on DC volts. Not looked at AC volts. I've cleaned all the switchery and checked the resistances which seem fine. Below are the readings I'm getting, 3V range looks slightly high, others are low except for the 10v on the 10v range oddly.

Input/Range/Result

2.50/3/2.55
2.50/10/2.38
5.00/10/4.8
7.50/10/7.3
10/10/10
10/30/9.9
98/100/96
252/300/265
325/600/314

I'm thinking it's the 3V range resistance(s) that are out and I need to look harder at them but does anyone have any other thoughts? This one came with as a complete kit, case, leads, the lot so I thought it deserved some wider knowledge input and attention before relegating it to the pile of shame.

Thanks - Andrew

Sinewave · 24th Dec 2017, 9:02 pm

I'll watch this with interest, as I've got a few which read low here and there and am wondering how easy it would be to get them back into cal.

24th Dec 2017, 6:35 pm	#1
Andrewausfa Octode Join Date: Dec 2010 Location: St Ives, Cambridgeshire, UK. Posts: 1,180	AVO 8 Mk 5 I picked this one up recently for a not a lot and going over it this afternoon found it's reading low on DC volts. Not looked at AC volts. I've cleaned all the switchery and checked the resistances which seem fine. Below are the readings I'm getting, 3V range looks slightly high, others are low except for the 10v on the 10v range oddly. Input/Range/Result 2.50/3/2.55 2.50/10/2.38 5.00/10/4.8 7.50/10/7.3 10/10/10 10/30/9.9 98/100/96 252/300/265 325/600/314 I'm thinking it's the 3V range resistance(s) that are out and I need to look harder at them but does anyone have any other thoughts? This one came with as a complete kit, case, leads, the lot so I thought it deserved some wider knowledge input and attention before relegating it to the pile of shame. Thanks - Andrew __________________ Invisible airwaves crackle with life. Or they should do. BVWS Member

24th Dec 2017, 9:02 pm	#2
Sinewave Octode Join Date: May 2016 Location: Oxfordshire/Bucks borders, UK. Posts: 1,604	Re: AVO 8 Mk 5 I'll watch this with interest, as I've got a few which read low here and there and am wondering how easy it would be to get them back into cal. __________________ Avometer, vintage Fluke and Marconi collector. Also interested in vintage Yaesu and KW.