Bush TV22 LOPt question - UK Vintage Radio Repair and Restoration Discussion Forum

Giulio Maiocco · 11th Mar 2008, 10:53 am

Hello,

I have seen somebody on this forum (maybe Beery?) offering new laminations for the TV22 LOPT, please could someone tell me how risky/difficult is to pull the old laminations from the LOPT and install the new ones? The laminations are quite a bit rusty. Also, how much for a new set of laminations?

Thanks a lot

Giulio Maiocco

Ed_Dinning · 11th Mar 2008, 10:23 pm

Hi Giulio, there were 2 types of lamination used used with these transformers. The early unes used a "T" shape, which was expensive and wasteful, the later ones used a longer "I" shape.
The primary windings can be extracted from the EHT overwing with some heat and a little care. This can easily be re-wound. The EHT overwind is virtually impossible to do due to the difficulty of getting the wire. Most faults seem to be on the primary and I have re-wound quite a few of these.
My experiments to produce a modern version of this transformer were only successful in as far as the primary were concerned. A lot more work is needed if I am to produce a non-wavewound EHT winding.

Ed

Giulio Maiocco · 12th Mar 2008, 10:10 am

Hi Ed,

The LOPT we are talking about is the later model, using the "I" shaped laminations. The transformer is still working, but my friend Angelo (the owner of this TV22) would like to change the laminations, as the ones currently mounted are quite a bit rusted and the core becomes a bit warm... My question is also about the core change of a spare LOPT Angelo is trying to get.

Thanks a lot

Giulio

11th Mar 2008, 10:53 am	#1
Giulio Maiocco Tetrode Join Date: Jan 2006 Location: Fossano (CN) Italy Posts: 71	Bush TV22 LOPt question Hello, I have seen somebody on this forum (maybe Beery?) offering new laminations for the TV22 LOPT, please could someone tell me how risky/difficult is to pull the old laminations from the LOPT and install the new ones? The laminations are quite a bit rusty. Also, how much for a new set of laminations? Thanks a lot Giulio Maiocco

11th Mar 2008, 10:23 pm	#2
Ed_Dinning Dekatron Join Date: Jan 2004 Location: Newcastle upon Tyne, Tyne & Wear, UK. Posts: 8,195	Re: Bush TV22 question Hi Giulio, there were 2 types of lamination used used with these transformers. The early unes used a "T" shape, which was expensive and wasteful, the later ones used a longer "I" shape. The primary windings can be extracted from the EHT overwing with some heat and a little care. This can easily be re-wound. The EHT overwind is virtually impossible to do due to the difficulty of getting the wire. Most faults seem to be on the primary and I have re-wound quite a few of these. My experiments to produce a modern version of this transformer were only successful in as far as the primary were concerned. A lot more work is needed if I am to produce a non-wavewound EHT winding. Ed

12th Mar 2008, 10:10 am	#3
Giulio Maiocco Tetrode Join Date: Jan 2006 Location: Fossano (CN) Italy Posts: 71	Re: Bush TV22 question Hi Ed, The LOPT we are talking about is the later model, using the "I" shaped laminations. The transformer is still working, but my friend Angelo (the owner of this TV22) would like to change the laminations, as the ones currently mounted are quite a bit rusted and the core becomes a bit warm... My question is also about the core change of a spare LOPT Angelo is trying to get. Thanks a lot Giulio