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Components and Circuits For discussions about component types, alternatives and availability, circuit configurations and modifications etc. Discussions here should be of a general nature and not about specific sets. |
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27th Jun 2017, 10:45 am | #1 |
Rest in Peace
Join Date: Oct 2006
Location: North Wiltshire, UK.
Posts: 638
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LA4730 pot core
I have a few of these in my spares box. Google isn't much help. Has anyone got any info on these items? The only other markings are 8720K which means nothing to me. TIA
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27th Jun 2017, 1:43 pm | #2 |
Dekatron
Join Date: Feb 2007
Location: Lynton, N. Devon, UK.
Posts: 7,088
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Re: LA4730 pot core
Nothing in my 1978/79 Mullard Quick Reference Guide (although the LA series does exist).
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27th Jun 2017, 3:13 pm | #3 |
Octode
Join Date: Feb 2009
Location: Bletchley, Buckinghamshire, UK.
Posts: 1,223
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Re: LA4730 pot core
Book 3 Part 4 of the Mullard Technical Handbook lists the RM cores with full data, but unfortunately mine is dated December 1979 and only goes up to LA4576. If you can find someone with a later edition they may be able to help.
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3rd Jul 2017, 5:28 pm | #4 |
Rest in Peace
Join Date: Oct 2006
Location: North Wiltshire, UK.
Posts: 638
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Re: LA4730 pot core
Thanks for looking both. I will continue to see what comes up in the future.
cheers. |
4th Jul 2017, 4:44 pm | #5 |
Nonode
Join Date: May 2007
Location: Redruth, Cornwall, UK.
Posts: 2,579
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Re: LA4730 pot core
Hi
I had a look in my two Quick Reference Guides dated 1984 and 1988 but unfortunately they're not listed. It would seem they are part of the RM series as Dave mentioned. With reference to page 411 in the 1988 Quick Reference Guide: RM5 (LA4000 series) RM6-R (LA4100 series) RM7 (LA4200 series) RM8 (LA4300 series) RM10 (LA4500 series) I'm fairly sure there were RM12 and RM14 pot cores which I take it are physically larger than say the RM10. On the back cover of the guide is listed the Mullard approved suppliers for their components. Regarding Ferrite for Inductors, it lists STC Electronic Services, Sasco, and Hawnt. I appreciate these businesses may not be operating now but I was thinking if anyone has a catalogue for the listed suppliers then the relevant technical data may be to hand. Out of interest, do you have a pic of your LA4730 and approximate dimensions? Regards Symon. |
5th Jul 2017, 1:35 am | #6 |
Nonode
Join Date: Oct 2010
Location: Tintinara, South Australia, Australia
Posts: 2,340
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Re: LA4730 pot core
Mullard ferrites became Ferroxcube and they are still around. Not sure they will be of any help for such an old product though.
http://www.ferroxcube.com/ Terry |
10th Jul 2017, 1:44 am | #7 |
Rest in Peace
Join Date: Oct 2006
Location: North Wiltshire, UK.
Posts: 638
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Re: LA4730 pot core
Thanks Symon and Terry. I do remember that I purchased mine from STC or whatever their retail outlet was called at the time. I will try to take a photo of one of mine. I can measure the coil former diameter as well. Their construction looks like the RM series cores that are available on eBay etc but your data would indicate that mine are larger than RM10. Someone may well have a catalogue which lists the larger cores. I guess that I must have had a catalogue when I bought my cores in the 1980s. STC were selling large job lots of quartz xtals, all frequencies, shapes and sizes at the time and I have the feeling that they were closing their retail outlet. I may be wrong though.
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11th Jul 2017, 3:48 am | #8 |
Nonode
Join Date: Oct 2010
Location: Tintinara, South Australia, Australia
Posts: 2,340
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Re: LA4730 pot core
I thought I had a substitution list for various brands of ferrites, but a dig through the boxes in the shed has failed to turn it up.
If it turns up, I'll scan and post it here. Terry |
11th Jul 2017, 9:14 pm | #9 |
Dekatron
Join Date: Jan 2004
Location: Newcastle upon Tyne, Tyne & Wear, UK.
Posts: 8,195
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Re: LA4730 pot core
Hi Hermit, a quick look through my data does not show any numbers going up as far as LA4730, I do seem to remember one of the forum members publishing a cross ref list a few years ago, anyone remember this?
The old standby of the STC "yellow bible" from 1982 only lists up to LA4547 Ed |