New Member and need to identify a set (Jonell A50) - Page 2 - UK Vintage Radio Repair and Restoration Discussion Forum

AC/HL · 15th Apr 2018, 2:37 pm

This one?: https://vintage-radio.net/forum/showthread.php?t=37327

GeorgeChristofi · 18th Apr 2018, 9:09 pm

Quote:

Originally Posted by Pete_kaye

I have one of these but not near it at the moment . I remember it being similar to AceA50 and used the circuit for it. The Jonell is using less components and probably could be improved. I do remember 6K7 and 6V6.
There was not much wrong with it but very weak without a good external aerial . Mine had no back on it so I improvised one.the original thread might still be on here,from 2007.

Many Thanks Pete. I have traced mine through to a certain extent and it is as you say, an Ace 50. I gave the chassis a dose of compressed air today in preparation for removing the stuff on the top of the chassis so I can deal with the rust. I'm also going to test the transformers and choke for operation as well as do an insulation test to make sure they are not burnt. After that, its a case of test, swap and change where needed and rebuild. There are some ropey looking caps under the trimmer plate. Did you take that off on yours or just work on it in situ?

Quote:

Originally Posted by AC/HL

This one?: https://vintage-radio.net/forum/showthread.php?t=37327

Many thanks for that. It has some useful info for me with regards to my set.

Pete_kaye · 20th Apr 2018, 11:56 am

I remember stopping at the stage where a plate was strongly soldered to the chassis and not going further Do you have pic of the back that you can post?

GeorgeChristofi · 20th Apr 2018, 5:55 pm

Mine was backless when I got it. I was hoping to find a picture somewhere of a back so I could recreate it somehow.

Pete_kaye · 22nd Apr 2018, 10:11 am

That's 2 of us . I made one from a piece off a radiogram .

GeorgeChristofi · 22nd Apr 2018, 1:32 pm

Ok... I have started taking it to bits.

First thing that jumps up is the fact that the mains transformer is just (as suggested here before) is just a heater supply. The HT is coming straight off the mains supply and being fed via a rotten 50 ohm resistor directly to pins 3 and 5 in what to me means that the tube is being used as a half wave rectifier. This also would explain the extra filter capacitors on the HT. I have removed both the transformer and the choke and found that at least one wire has chafed through to the chassis causing a short, also a heater wire has been melted by contact to a valve base. Many other issues with the set. I quickly metered out the on/off switch and that seems to be open too. I'm hoping its a dirt issue rather than full failure but we shall see.

This is going to be more in depth than just a quick cap swap, especially now I am dealing with a live chassis set. I shall keep you all informed!

For those who want to see pre dismantle pictures, I loaded a quick gallery at http://www.terminalcomputers.com/radio/index.html

George

AC/HL · 22nd Apr 2018, 9:31 pm

Continued here: https://www.vintage-radio.net/forum/...20#post1037320

15th Apr 2018, 2:37 pm	#21
AC/HL Dekatron Join Date: Nov 2003 Location: Heckmondwike, West Yorkshire, UK. Posts: 9,642	Re: New Member and need to identify a set (Jonell) This one?: https://vintage-radio.net/forum/showthread.php?t=37327

20th Apr 2018, 11:56 am	#23
Pete_kaye Octode Join Date: Jun 2005 Location: Sheffield, South Yorkshire, UK. Posts: 1,227	Re: New Member and need to identify a set (Jonell A50) I remember stopping at the stage where a plate was strongly soldered to the chassis and not going further Do you have pic of the back that you can post?

20th Apr 2018, 5:55 pm	#24
GeorgeChristofi Triode Join Date: Apr 2018 Location: Northampton, Northamptonshire, UK. Posts: 41	Re: New Member and need to identify a set (Jonell A50) Mine was backless when I got it. I was hoping to find a picture somewhere of a back so I could recreate it somehow.

22nd Apr 2018, 10:11 am	#25
Pete_kaye Octode Join Date: Jun 2005 Location: Sheffield, South Yorkshire, UK. Posts: 1,227	Re: New Member and need to identify a set (Jonell A50) That's 2 of us . I made one from a piece off a radiogram .

22nd Apr 2018, 1:32 pm	#26
GeorgeChristofi Triode Join Date: Apr 2018 Location: Northampton, Northamptonshire, UK. Posts: 41	Re: New Member and need to identify a set (Jonell A50) Ok... I have started taking it to bits. First thing that jumps up is the fact that the mains transformer is just (as suggested here before) is just a heater supply. The HT is coming straight off the mains supply and being fed via a rotten 50 ohm resistor directly to pins 3 and 5 in what to me means that the tube is being used as a half wave rectifier. This also would explain the extra filter capacitors on the HT. I have removed both the transformer and the choke and found that at least one wire has chafed through to the chassis causing a short, also a heater wire has been melted by contact to a valve base. Many other issues with the set. I quickly metered out the on/off switch and that seems to be open too. I'm hoping its a dirt issue rather than full failure but we shall see. This is going to be more in depth than just a quick cap swap, especially now I am dealing with a live chassis set. I shall keep you all informed! For those who want to see pre dismantle pictures, I loaded a quick gallery at http://www.terminalcomputers.com/radio/index.html George

22nd Apr 2018, 9:31 pm	#27
AC/HL Dekatron Join Date: Nov 2003 Location: Heckmondwike, West Yorkshire, UK. Posts: 9,642	Re: New Member and need to identify a set (Jonell A50) Continued here: https://www.vintage-radio.net/forum/...20#post1037320