Tubes with "Hammond" silk screened on them typically have a code consisting of two pairs of numbers separated by a dash.The format is YY-WW, where YY is the last two digits of the year and WW is the number of the week in that year. Many capacitors have a date code on them, but some do not.When you hit the "Submit" button you will see a message advising "Update Successful".
Thanks to the Electronics Industry Association (EIA) code conveniently placed on them by the manufacturer, many individual components can be dated to the year and week of production.
Due to Hammond and Leslie purchasing components in large quantities, using these codes as definitive signposts will not produce an accurate "born on" date.
Later Leslie motors have a sticker on them indicating their manufacturing date.
The formula is XXX-YYWW, where XXX is the manufacturer EIA code (190 indicates General Instrument in the present example), YY is the last two digits of the year of manufacture, and WW is the week of manufacture.
All available information must be taken as a whole, and, combined with some general tips and observations provided below, a narrow range of probable production years can be arrived at which in many cases will be accurate enough for most people's desires.
One thing to remember in this chronological quest is these instruments were built to be played, not (in most cases) to become museum pieces.Just to get started, 21H's are 1951 to 1958, 22H's are 1958 to 1963, 122/142/147/145's are late 1963 and later.Any other single speed model (45/47/51) is prior to late 1963.To help determine the manufacturing date of Hammond organs and Leslie speakers.Use this form if you would like to submit your Hammond Organ for inclusion in these tables.3227204 is a Tung-Sol tube manufactured during the fourth week of 1972.Tung-Sol 6550 tubes made for other companies (like RCA) have a four-digit date code only.Most of the tone generator wax and Mylar capacitors do, as well as pre- and power amplifier multi-section can electrolytic capacitors.The code typically takes the form of YYWW, where YY is the last two digits of the production year and WW is the production week. All of the speakers in Hammond organs, Hammond Tone Cabinets and Leslie cabinets dating from 1946 forward that I have seen have production date codes stamped on them. The coding scheme is XXXYWW where XXX is the company EIA code (Jensen = 220, Rola = 285, Heppner = 575), Y is the last digit of the production year, and WW is the production week.In the example shown, 190-7215 was made in the 15th week of 1972.Earlier Leslie motors have a stamped four digit code.