Welcome to Australia's only Vintage Radio and Television discussion forums. You are not logged in. Please log in below, apply for an account or retrieve your password.
Australian Vintage Radio Forums
  Home  ·  About Us  ·  Discussion Forums  ·  Glossary  ·  Outside Links  ·  Policies  ·  Services Directory  ·  Safety Warnings  ·  Tutorials

Tech Talk

Forum home - Go back to Tech talk

 Rola speakers date code?
« Back · 1 · Next »
 Return to top of page · Post #: 1 · Written at 11:53:15 AM on 7 September 2018.
Sue's avatar
 Sue
 Location: Daylesford, VIC
 Member since 13 January 2011
 Member #: 809
 Postcount: 326

Do Australian Rola speakers have a date code as part of their markings? I'm looking at one now marked 434/15; obviously the 15 means 15 ohms, but does 434 tell the date?


 
 Return to top of page · Post #: 2 · Written at 2:44:32 PM on 7 September 2018.
GTC's avatar
 GTC
 Location: Sydney, NSW
 Member since 28 January 2011
 Member #: 823
 Postcount: 6678

Going by various articles on speaker dating, if they followed the EIA coding standard, I'm guessing week 34 of 1954. I gather the EIA date code changed to 4 digits around 1961, so if it were 1964 I'd expect it to be 6434.

Does 1954 seem to suit the application?


 
 Return to top of page · Post #: 3 · Written at 11:19:33 AM on 8 September 2018.
Sue's avatar
 Sue
 Location: Daylesford, VIC
 Member since 13 January 2011
 Member #: 809
 Postcount: 326

I don't think so, it's a Rola C8MX with a big ferrite magnet. I thought perhaps 1964. Not 70s of course, by then they were Plessey.


 
 Return to top of page · Post #: 4 · Written at 4:13:54 PM on 8 September 2018.
GTC's avatar
 GTC
 Location: Sydney, NSW
 Member since 28 January 2011
 Member #: 823
 Postcount: 6678

Model 8MX is detailed in this February 1965 catalog: http://www.amvcnsw.com.au/austin1800/Service_Manuals/RolaLoudSpeaker.pdf

It seems the X indicates twin cone. It mentions that the C prefix indicates the "latest" barium ferrite magnet, so that date code may be 1964.


 
 Return to top of page · Post #: 5 · Written at 8:12:45 PM on 8 September 2018.
Sue's avatar
 Sue
 Location: Daylesford, VIC
 Member since 13 January 2011
 Member #: 809
 Postcount: 326

It probably is 1964, then. Elsewhere in Tech Talk there's a 1959 Kriesler with a Rola speaker marked "59" before the impedance code, suggesting that is indeed where they put the date code.

Thanks for the lead on the catalogue, that'll be useful when old speakers turn up. I've got the 1971 Plessey Loudspeaker catalogue, it will be interesting comparing the two.


 
 Return to top of page · Post #: 6 · Written at 10:09:58 PM on 12 September 2018.
Normf's Gravatar
 Location: Cargo, NSW
 Member since 19 June 2018
 Member #: 2256
 Postcount: 96

I have a Rola 12PX it has 1961 stamped on the rim and 30/15 on one of the radial arms near the terminals.
I'm guessing it's 15 ohm but don't know what the 30 indicates.
It is twin cone unit, it is marked 12PX00 on the magnet.
Looking at the PDF in link from GTC it shows that it has an F30 diaphragm, may that's what the 30 indicates.


 
 Return to top of page · Post #: 7 · Written at 5:02:33 PM on 13 September 2018.
Garyoz's avatar
 Location: Perth, WA
 Member since 19 November 2008
 Member #: 381
 Postcount: 240

There are a few Rola documents on Kev's site that my assist with the codes.

https://www.kevinchant.com/general-information.html


 
« Back · 1 · Next »
 You need to be a member to post comments on this forum.

Sign In

Username:
Password:
 Keep me logged in.
Do not tick box on a computer with public access.