Marconi P20B questions - UK Vintage Radio Repair and Restoration Discussion Forum

stevehertz · 11th Mar 2021, 1:16 pm

On a Macaroni P20B portable..

See photo 1. There's a small black oblong fibre plate through which two white wires pass. There's a nut missing from the bolt. Is that all that's missing? just replace the missing 6BA nut?

See photos 2 & 3. Someone has cut off the four pin battery connector plug. I need to know the positions of the black, red, white and blue wires for resoldering purposes. If you know this, please refer to the side of the plug where the wires are inserted.

Finally, I don't suppose anyone has got a donor set for parts as the circular dark brown dial scale is damaged on mine.

Thanks!

ms660 · 11th Mar 2021, 2:01 pm

https://www.vintage-radio.net/forum/...6&d=1256665399

Red = HT+
Black = HT-

Blue = LT+
White = LT-

So far as I can make out.

Lawrence.

snowman_al · 11th Mar 2021, 2:02 pm

Just a 6BA nut, not even a small washer...
No battery plug on mine either, but Red is +ve HT, Black is -ve HT, Blue is +ve LT and White is -ve LT if it helps.
And an old thread here with a diagram https://www.vintage-radio.net/forum/...92&postcount=3 (#7 I think) but several other results for B114 battery replacement.
Alan

stevehertz · 11th Mar 2021, 2:33 pm

Excellent, thank you gentlemen.

Now, just that dial face needed..

11th Mar 2021, 1:16 pm	#1
stevehertz Dekatron Join Date: Sep 2011 Location: Rugeley, Staffordshire, UK. Posts: 8,826	Marconi P20B questions On a Macaroni P20B portable.. See photo 1. There's a small black oblong fibre plate through which two white wires pass. There's a nut missing from the bolt. Is that all that's missing? just replace the missing 6BA nut? See photos 2 & 3. Someone has cut off the four pin battery connector plug. I need to know the positions of the black, red, white and blue wires for resoldering purposes. If you know this, please refer to the side of the plug where the wires are inserted. Finally, I don't suppose anyone has got a donor set for parts as the circular dark brown dial scale is damaged on mine. Thanks! Attached Thumbnails __________________ A digital radio is the latest thing, but a vintage wireless is forever.. Last edited by stevehertz; 11th Mar 2021 at 1:36 pm.

11th Mar 2021, 2:01 pm	#2
ms660 Dekatron Join Date: Apr 2011 Location: Cornwall, UK. Posts: 13,454	Re: Marconi P20B questions https://www.vintage-radio.net/forum/...6&d=1256665399 Red = HT+ Black = HT- Blue = LT+ White = LT- So far as I can make out. Lawrence.

11th Mar 2021, 2:02 pm	#3
snowman_al Octode Join Date: Dec 2018 Location: Llandeilo, West Wales, UK. Posts: 1,092	Re: Marconi PB20 questions Just a 6BA nut, not even a small washer... No battery plug on mine either, but Red is +ve HT, Black is -ve HT, Blue is +ve LT and White is -ve LT if it helps. And an old thread here with a diagram https://www.vintage-radio.net/forum/...92&postcount=3 (#7 I think) but several other results for B114 battery replacement. Alan Attached Thumbnails __________________ Never Leave Well Enough Alone...

11th Mar 2021, 2:33 pm	#4
stevehertz Dekatron Join Date: Sep 2011 Location: Rugeley, Staffordshire, UK. Posts: 8,826	Re: Marconi P20B questions Excellent, thank you gentlemen. Now, just that dial face needed.. __________________ A digital radio is the latest thing, but a vintage wireless is forever..