It is currently Thu Aug 16, 2018 3:27 am

Home-made paint pot tuning coil

Posts: 196
Joined: Wed Mar 05, 2014 7:52 pm
Location: Lancashire

Home-made paint pot tuning coil

Post by Sparks » Sun Jan 10, 2016 9:55 pm

Home-made tuning coil. The screening can is made from a small Humbrol paint pot as shown in the picture. I burned the old paint out and sprayed it with matt grey primer obtained from Halfords (UK). The black base is a disk of 3mm shiny black acrylic sheet. The connections are 6ba nuts & bolts and solder tags. Inside it are three 47uH chokes. Two in series for the aerial coil, with the aerial going to the centre. The other choke lies next to the lower aerial coil and forms the reaction! Works extremely well!
Paint pot tuning coil.JPG

Posts: 2513
Joined: Sun Jun 10, 2012 7:23 pm
Location: Basildon

Re: Home-made paint pot tuning coil

Post by crackle » Mon Jan 11, 2016 11:35 am

What a good idea, and it looks very professional.

Posts: 6972
Joined: Sun Aug 14, 2011 11:02 am
Location: Co. Limerick

Re: Home-made paint pot tuning coil

Post by Michael Watterson » Tue Jan 12, 2016 11:04 am

Is it Aluminium Alloy or Steel?

There is a scientific reason by coil covers are aluminium, copper, brass and never tin-plate, except for coils enclosed in an outer ferrite or dust cup / cover. Hence coils with air, brass, dust, ferrite core are usually alloy cover and the transistor circuit coils with outer ferrite cup only use a tinned steel cover for mechanical support, not screening.

Posts: 287
Joined: Mon Apr 23, 2012 6:42 pm
Location: Witney, Oxon

Re: Home-made paint pot tuning coil

Post by Herald1360 » Fri Jan 15, 2016 1:26 pm

The rust on the tin suggests tinplated steel. The tiny resistor sized ferrite cored inductors inside are probably far enough away from the cover not to be affected much by its material.

For individual one off assemblies, they are what they are and if they work well, fine. Reproducibility for production runs doesn't matter!

Return to General Work Shop Discussion

Who is online

Users browsing this forum: No registered users and 1 guest