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General Vintage Technology Discussions For general discussions about vintage radio and other vintage electronics etc. |
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8th Aug 2020, 4:05 am | #1 |
Heptode
Join Date: May 2005
Location: Adelaide, South Australia
Posts: 541
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AVO VCM Data book errors ?
Is anyone aware of a list or similar of AVO VCM data book errors or inconsistencies, I've came across a couple just recently and was thinking there there may be more.
I was checking a new in box LL4 - Avo data gives 18mA as the anode current, after going through the preliminaries I switched to TEST and saw the meter needle rise up close to 40mA, after quickly double checking the bias setting and found it correct I switched off - something was not right. An internet search found conflicting info that supports 40mA anode current - I suspect the Avo book is incorrect. EL34/6CA7 there is an entry for each in the data book with slightly different data most notably the anode current - I was of the opinion that they were one and the same. It is not surprising for errors to creep in after all it was compliled by humans. |
8th Aug 2020, 11:26 am | #2 |
Moderator
Join Date: Jan 2003
Location: Ipswich, Suffolk, IP4, UK.
Posts: 21,193
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Re: AVO VCM Data book errors ?
In the 23rd Edition of The AVO Valve Data Manual the CT160 settings for testing an ECC88 are incorrectly given as 641237510. This should read 641237410
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Graham. Forum Moderator Reach for your meter before you reach for your soldering iron. |
8th Aug 2020, 12:13 pm | #3 |
Nonode
Join Date: Mar 2008
Location: Aberdeen, UK.
Posts: 2,839
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Re: AVO VCM Data book errors ?
There have been a number of inconsistencies in old AVO VDM's over the years. Many of us own an old 2nd hand one which have corrections pencilled-in or inked-in, at the bottom of pages, by previous owners. And, have made additions ourselves.
However, if in doubt, I always cross reference to an old Iliffe Valve Data Book, or a set of old Bernard's VD books. Cross-referencing seemingly irrefutable data is something I learnt from my previous time-consuming retirement pastime - Family History Research. For example, the LDS Genealogy Data Base is the biggest in the world & is an ideal quick starting point, but like valve data, I learnt to double or mostly treble check against the likes of Parish Records & National BMD records, before being absolutely sure for Family Tree insertion. So -AVO's VDM isn't the "be all & end all" of valve data, or the correct setting of their own VCM Thumbwheel Switch Numbering. Regards, David |
10th Aug 2020, 3:47 pm | #4 |
Heptode
Join Date: May 2005
Location: Adelaide, South Australia
Posts: 541
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Re: AVO VCM Data book errors ?
I keep both Miniwatt and RCA data books on the shelf and do refer to them if something doesn't seem "right" - most of the time if I do have reason to reach for either book I find the settings match the Avo data manual, but there have been a few exceptions, my homebuilt tester is wired so the Avo switch and voltage settings can be used which is great, it is nice to be able to use the same manual for that and also my MKI/II VCM, I guess I'll just have to do the same as everyone else and pencil in any corrections I find.
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