The PHILCO Phorum
40-190 What is this? - Printable Version

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40-190 What is this? - Edisla - 07-19-2015

I don't think I posted this here but if I did sorry.

What is going on here?

[Image: http://i1289.photobucket.com/albums/b519/Edisla/IMG_2673_zps03jaajar.jpg]

RE: 40-190 What is this? - morzh - 07-19-2015

I wonder if his antenna coil was gone and this was no he repaired it.

RE: 40-190 What is this? - Arran - 07-19-2015

(07-19-2015, 03:44 PM)morzh Wrote:  I wonder if his antenna coil was gone and this was no he repaired it.

I'm not sure, most of the 1940 Philcos have a built in loop antenna for broadcast, and this one is no exception. It does not look very official though, like someone wound a coil around a toilet paper roll. Maybe it's some sort of home made noise filter since it only has one winding by the looks of things? Pull the chassis out and see if anything is smoked under there.
Regards
Arran

RE: 40-190 What is this? - DeckApe - 07-20-2015

Either that's a retrofit or my 40-190 is missing a toilet paper spindle paralleled to that cardboard muffler under the hood.

I'd like to know what the intent and the effect were...

RE: 40-190 What is this? - Joeztech - 08-01-2015

I would suggest that you disconnect the added toilet paper roll antenna and then disconnect each lead of the original rotating loop antenna below and check for open circuits in one coil winding. The antenna coil can be repaired but you would have to unfasten the electrostatic outer shield covering to get at the coils inside. Most likely a wire has corroded apart at one of the fastening points inside. I repaired and restored a 40-201 and worked on the one in it. This electrostatically shielded antenna loop was only used in 1940 models. It helps eliminate noise interference from neon lights and motors that may have a spark jumping inside them. The antenna circuit of the 1940 models with this feature have a high impedance RF amplifier grid circuit. 1941 models changed to a low impedance loop and grid circuit in the RF amplifier stage to reduce noise.

Joe

RE: 40-190 What is this? - Edisla - 08-02-2015

That should be easy since the covering is no longer on the antenna. You can see it exposed in the pic down left.

RE: 40-190 What is this? - Edisla - 08-02-2015

FYI - its not a toilet paper roll, something much sturdier. ;)

RE: 40-190 What is this? - DeckApe - 08-16-2015

I just realized the cardboard covering was missing off your antenna. There was some sort of a metal mesh grid in there originally, which I'm assuming was part of the antenna. This might be intended as a sub for said mesh grid.

RE: 40-190 What is this? - Edisla - 10-07-2015

I believe the mesh is to help reduce noise and is not really needed.

I plan on just covering it to look original and not worry about the mesh.

I could be wrong ;)

RE: 40-190 What is this? - Edisla - 10-07-2015

FYI - Still not sure what this is Icon_sad

RE: 40-190 What is this? - Ron Ramirez - 10-07-2015

Well, one thing is for certain, and that is the fact that the "toilet paper" coil is not original...