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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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28th Dec 2015, 4:35 pm | #1 |
Triode
Join Date: Aug 2005
Location: Woking, Surrey, UK.
Posts: 34
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Aladdin Coil Formers
Does anyone happen to have any data on Aladdin Industries coil formers circa 1950's 3/8in diameter, about an inch high, dust slug, twin lug mounting?
I'm looking for accurate dimension information so that I can make some replicas. Thanks |
28th Dec 2015, 9:13 pm | #2 |
Dekatron
Join Date: Feb 2003
Location: Cottingham, East Yorkshire, UK.
Posts: 5,737
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Re: Aladdin Coil Formers
I've attached a few pics of an Aladdin style former and a rough sketch, which might help.
I say Aladdin 'type' because there is no maker's name on the former, but I'm pretty sure that's what it is. I've shown the dimensions in mm, though of course at the time, they would have been imperial, but in 'old money' the size does correspond to 3/8" diam x 1" tall, with a 1/4" diameter slug. The former has two pairs of holes in the base for anchoring wire, as well as two for fixing. The top of the former has a rim onto which a paxolin ring with six solder lugs is a push fit. (The sketch is not to scale, but I hope it has all the info you may need). As an aside, I wouldn't have thought Aladdin formers would perform well at higher frequencies, being black plastic, which may have a high carbon content and be lossy. Easy way to find out is to pop one in a microwave oven for say 30 secs, with a bowl of water (but not actually in the water!). If it doesn't get hot at microwave frequencies it should be fine at HF, if not VHF). Hope that helps a bit.
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David. BVWS Member. G-QRP Club member 1339. |
28th Dec 2015, 9:32 pm | #3 |
Dekatron
Join Date: Apr 2012
Location: Wiltshire, UK.
Posts: 13,951
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Re: Aladdin Coil Formers
Those style of coil-formers were used in the WWII-era RF25, RF26 and RF27 "Gee" frontends which worked happily up to 80-odd MHz.
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28th Dec 2015, 11:05 pm | #4 |
Banned
Join Date: Jun 2015
Location: Mareeba, North Queensland, Australia
Posts: 2,704
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Re: Aladdin Coil Formers
Alas it's one thing that "hobby" stores don't keep anymore!! I have loads of excellent receiver schematics that I have always wanted to try, but no coil data.
Or if there is coil data there are no formers available to wind them. Another thing that Australian magazines did, was to use "coil packs", where all the coils are mounted onto a sub chassis usually with the mixer/oscillator and RF valve bases attached, and in some cases a very nice 3 gang tuner. One area of my non expertise is RF !! at least RF at DC levels, as the other engineers called HF radio. ( All my experience with RF starts at 2.2 gigs and upwards). I have tried all the commonly available plastics ( pill bottles, PVC electrical conduit, perspex rod, all with horrible Q ) even paxoilin tubing is now unavailable, and that would do for frequencies up to 30 megs. I did fix one thing though, when all the "old" stores closed down, I bought up every IF transformer I could find!. But that means I only have 455 khZ IF's as FM didn't start until just a few years ago in Australia ( mebbe 30 years ago) and double conversion receivers were not very common here. I am interested in what ssaunders comes up with !! regards Joe |