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

General Discussion

Forum home - Go back to General discussion

 Aerial Coil Replacement
« Back · 1 · Next »
 Return to top of page · Post #: 1 · Written at 7:17:19 PM on 21 October 2019.
Alarum's Gravatar
 Location: Toowoomba, QLD
 Member since 6 July 2019
 Member #: 2359
 Postcount: 12

Good evening,

Is it possible to find replacements for a melted aerial coil?

I noticed that one of the tuning screws on the coil was sitting at an angle and decided to remove it to have a look. Inside, I found the coil literally melted.

The radio is a Music Masters A6 short and medium wave model. The coil attaches to the aerial via the broadcast switch.

So what is the part actually called? How would it have melted like that? Most important, is it possible to find replacements?

Antenna Coil


 
 Return to top of page · Post #: 2 · Written at 10:16:34 PM on 21 October 2019.
Marcc's avatar
 Location: Wangaratta, VIC
 Member since 21 February 2009
 Member #: 438
 Postcount: 3698

It is interesting, I have never seen one melted. It would be an idea to post a photo; Might have a circuit. More commonly but rare to see, an IF primary do that when someone shorts the trimmer to ground (as it has b+ on it).

That if the fact it may be lightning strike, or the unit is without ground and shorted via that coil. I would be a tad suspect of its electrical integrity at this early point.

The aerial coil, oscillator coil and tuning gang are a matched set. So getting the correct one may be a challenge, but not necessarily impossible.

Marc


 
 Return to top of page · Post #: 3 · Written at 3:25:32 AM on 23 October 2019.
Brad's avatar
 Administrator
 Location: Greenwich, NSW
 Member since 15 November 2005
 Member #: 1
 Postcount: 5497

Photo uploaded.


‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾
A valve a day keeps the transistor away...

 
 Return to top of page · Post #: 4 · Written at 7:14:22 AM on 23 October 2019.
Fred Lever's Gravatar
 Location: Toongabbie, NSW
 Member since 19 November 2015
 Member #: 1828
 Postcount: 569

Just looked at the photo, um, that's a problem!

I wonder if the damage is 1/ heat related or 2/ ageing or 3/ chemical reaction?

If its heat, must be a lightning discharge and its "fried".

The incoming coil has to match the original for inductance at least, to achieve lining up with the tuning dial markings.

Being practical and a gung ho type, I would just wire in a similar looking aerial coil from some radio and see if the core would adjust to get stations where the dial says they should be. That is a very simplistic approach but cannot hurt anything and you may get lucky and hit the sweet spot and the drama is fixed.
Practical problem is you need a box full of old coils to try!

Fred.


 
 Return to top of page · Post #: 5 · Written at 5:10:36 PM on 23 October 2019.
Ian Robertson's Gravatar
 Location: Belrose, NSW
 Member since 31 December 2015
 Member #: 1844
 Postcount: 1289

I have an AWA WW2 Amenities Receiver that runs on 6vDC.

The aerial coil in that was similarly cooked.

Not hard to work out what happened. The antenna wire fell across the battery.

Maybe your set met with a similar accident? Car battery and charger in the workshop?


 
 Return to top of page · Post #: 6 · Written at 5:31:29 PM on 23 October 2019.
Alarum's Gravatar
 Location: Toowoomba, QLD
 Member since 6 July 2019
 Member #: 2359
 Postcount: 12

Looking at my photos that I took of the wiring before touching anything, the adjustment screw underneath was still sitting at an angle so I'm 99.9% confident that the coil was already melted when I bought the radio.

Sounds like it will be a hit or miss affair with finding a replacement coil. This radio might just have to sit on the shelf for a bit!


 
« 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.