Reading potentiometer date codes - UK Vintage Radio Repair and Restoration Discussion Forum

magicbus · 5th Mar 2020, 9:22 pm

Hi all

I want to find out about date codes on Morganite and Lesa branded pots from the 1960's (primarily from old guitars)

I have seen numerous examples, some seem not to have any codes, some do. Whether these even are date codes I don't know

I have seen the following codes on some early 60s Lesa pots - stamped on the side

1MΩA 1567 5 15
0.25MΩ 1104 12 14
0.25MΩ 1104 1 15

I feel the 1567 and 1104 are part numbers

Then I have morganite pots with codes like
AV
UL
VM

I was told that XA =jan 66 - but if A= jan, M makes no sense!

- could probably find more examples

Finally I have a pot with the following inked on the side - not sure what brand this is - again early 60s guitar pot
DCC 1MΩQIC MAR808161

thanks all, hope someone here can help me!
Jules

Diabolical Artificer · 6th Mar 2020, 7:00 am

If they're Gibson pots there's this yank on Youtube who knows his date codes, goes by Trogladite Guitar something. Knowing what people are like about guitars there's bound to be a site about pot codes.
Ggfgv
Andy.

Paul JD · 6th Mar 2020, 6:36 pm

Any of the "big name" American guitars from that era (Fender, Gibson etc) will have had CTS or Stackpole pots which are easy to date, lots of information here http://www.guitarhq.com/pots.html. Unfortunately that doesn't seem to help with yours.

Lesa pots were made in Italy which would suggest yours may have come from Eko or Vox guitars? (Vox guitars were made in Italy at the Eko factory). This article seems to suggest it might not be possible to date Lesa pots https://www.vintageguitarandbass.com..._pot_codes.php

trobbins · 6th Mar 2020, 11:36 pm

Unravelling a date code can sometimes require lots of examples (and effort to acquire a large sample size), with some alternative dating information to support the accuracy of the date code. But well worth it imho.

One example of a date code 'chase' - https://www.guitargear.net.au/discus...?topic=50550.0

magicbus · 8th Mar 2020, 11:12 pm

Thanks for the answers so far - I was hoping the dating scheme would already be well-known. If 'I' got skipped as a month, (as was the case in the guitargear.net.au thread) it would make M=December

Will go through all my pots and re-evaluate!

Potentially one step closer - thanks again.

5th Mar 2020, 9:22 pm	#1
magicbus Diode Join Date: Mar 2020 Location: Milton Keynes, Buckinghamshire, UK. Posts: 2	Reading potentiometer date codes Hi all I want to find out about date codes on Morganite and Lesa branded pots from the 1960's (primarily from old guitars) I have seen numerous examples, some seem not to have any codes, some do. Whether these even are date codes I don't know I have seen the following codes on some early 60s Lesa pots - stamped on the side 1MΩA 1567 5 15 0.25MΩ 1104 12 14 0.25MΩ 1104 1 15 I feel the 1567 and 1104 are part numbers Then I have morganite pots with codes like AV UL VM I was told that XA =jan 66 - but if A= jan, M makes no sense! - could probably find more examples Finally I have a pot with the following inked on the side - not sure what brand this is - again early 60s guitar pot DCC 1MΩQIC MAR808161 thanks all, hope someone here can help me! Jules

6th Mar 2020, 7:00 am	#2
Diabolical Artificer Dekatron Join Date: Jul 2009 Location: Sleaford, Lincs. UK. Posts: 7,670	Re: Reading potentiometer date codes If they're Gibson pots there's this yank on Youtube who knows his date codes, goes by Trogladite Guitar something. Knowing what people are like about guitars there's bound to be a site about pot codes. Ggfgv Andy. __________________ Curiosity hasn't killed this cat...so far.

6th Mar 2020, 6:36 pm	#3
Paul JD Pentode Join Date: Oct 2018 Location: Coventry, West Midlands, UK. Posts: 220	Re: Reading potentiometer date codes Any of the "big name" American guitars from that era (Fender, Gibson etc) will have had CTS or Stackpole pots which are easy to date, lots of information here http://www.guitarhq.com/pots.html. Unfortunately that doesn't seem to help with yours. Lesa pots were made in Italy which would suggest yours may have come from Eko or Vox guitars? (Vox guitars were made in Italy at the Eko factory). This article seems to suggest it might not be possible to date Lesa pots https://www.vintageguitarandbass.com..._pot_codes.php

6th Mar 2020, 11:36 pm	#4
trobbins Heptode Join Date: Oct 2009 Location: Melbourne Australia Posts: 901	Re: Reading potentiometer date codes Unravelling a date code can sometimes require lots of examples (and effort to acquire a large sample size), with some alternative dating information to support the accuracy of the date code. But well worth it imho. One example of a date code 'chase' - https://www.guitargear.net.au/discus...?topic=50550.0

8th Mar 2020, 11:12 pm	#5
magicbus Diode Join Date: Mar 2020 Location: Milton Keynes, Buckinghamshire, UK. Posts: 2	Re: Reading potentiometer date codes Thanks for the answers so far - I was hoping the dating scheme would already be well-known. If 'I' got skipped as a month, (as was the case in the guitargear.net.au thread) it would make M=December Will go through all my pots and re-evaluate! Potentially one step closer - thanks again.