Eddystone 750 wreck - Page 5 - UK Vintage Radio Repair and Restoration Discussion Forum

Vintage Engr · 9th Oct 2021, 4:32 pm

Congratulations, a lot of hard work & perseverance, but a really great result.

I also have a 750 stored away that I keep meaning to start on. Mine's a 'one-owner from-new', so I'm fortunate in that respect, - I got it from a house-clearance. There is even an original letter inside from Stratton & Co. , referring to a replacement volume control fitted by them.
I've just ordered some steel fishing line to replace the broken drive-cord, so the fun will no doubt start!

David.

PJL · 9th Oct 2021, 8:24 pm

You will have to lift the band 1 coils in the RF box to replace the Hunts used for AGC decoupling and any others you feel inclined to do. There are a couple of other Hunts and the two small rat turds used as LT decoupling.

The 2nd oscillator box contains 3 Hunts, two for LT decoupling and one for anode feed decoupling. The BFO box also contains three suspect capacitors (black) similarly used for decoupling. The 0.1uF bolt down capacitors all tested leaky so I just replaced them all. The square capacitors tested OK but I replaced a couple as they were coupling capacitors. I checked all resistors and replaced those out of tolerance.

The HT voltage measured too high, enough to overheat the VR150, in part due to my mains voltage of 248V. I used a 24V bucking transformer to bring it down to a more reasonable figure.

I made brass brackets for the 0.1uF capacitors but I see other restorers have just soldered them to the nearest earth tag.

I don't regret doing the full restoration in one hit as you won't want to fault find and fix as you go as these sets were not designed with the service engineer in mind

deliverance · 9th Oct 2021, 9:06 pm

Your hard work has paid off looks the business now.

Radio1950 · 17th Oct 2021, 8:26 pm

Congratulations.
Very interesting read.

I am starting today to assist just a little with restoration and alignment of a 750.

9th Oct 2021, 4:32 pm	#81
Vintage Engr Heptode Join Date: Jan 2008 Location: Shrewsbury, Shropshire, UK. Posts: 838	Re: Eddystone 750 wreck Congratulations, a lot of hard work & perseverance, but a really great result. I also have a 750 stored away that I keep meaning to start on. Mine's a 'one-owner from-new', so I'm fortunate in that respect, - I got it from a house-clearance. There is even an original letter inside from Stratton & Co. , referring to a replacement volume control fitted by them. I've just ordered some steel fishing line to replace the broken drive-cord, so the fun will no doubt start! David.

9th Oct 2021, 8:24 pm	#82
PJL Dekatron Join Date: Sep 2005 Location: Seaford, East Sussex, UK. Posts: 5,997	Re: Eddystone 750 wreck You will have to lift the band 1 coils in the RF box to replace the Hunts used for AGC decoupling and any others you feel inclined to do. There are a couple of other Hunts and the two small rat turds used as LT decoupling. The 2nd oscillator box contains 3 Hunts, two for LT decoupling and one for anode feed decoupling. The BFO box also contains three suspect capacitors (black) similarly used for decoupling. The 0.1uF bolt down capacitors all tested leaky so I just replaced them all. The square capacitors tested OK but I replaced a couple as they were coupling capacitors. I checked all resistors and replaced those out of tolerance. The HT voltage measured too high, enough to overheat the VR150, in part due to my mains voltage of 248V. I used a 24V bucking transformer to bring it down to a more reasonable figure. I made brass brackets for the 0.1uF capacitors but I see other restorers have just soldered them to the nearest earth tag. I don't regret doing the full restoration in one hit as you won't want to fault find and fix as you go as these sets were not designed with the service engineer in mind Attached Thumbnails

9th Oct 2021, 9:06 pm	#83
deliverance Heptode Join Date: Apr 2015 Location: Manchester, UK. Posts: 710	Re: Eddystone 750 wreck Your hard work has paid off looks the business now.

17th Oct 2021, 8:26 pm	#84
Radio1950 Hexode Join Date: Apr 2017 Location: Buderim, Queensland, Australia. Posts: 428	Re: Eddystone 750 wreck Congratulations. Very interesting read. I am starting today to assist just a little with restoration and alignment of a 750.