Green Hunts Caps - UK Vintage Radio Repair and Restoration Discussion Forum

PaulR · 1st Jun 2020, 8:24 pm

I have been overhauling an Armstrong 400 series receiver which my son bought recently. It is full of green Hunts capacitors, both electrolytic and lower value film ones of some sort. It was distorting at low frequencies and replacing all the electrolytics has cured this. That leaves the film ones. I know the reputation of Mouldseal caps but have never come across these later ones which seem to be encased in metal under the green plastic cover. Does anyone have any experience of the reliability of them? The amp appears to work ok and there are so many in the pre-amp boards in particular that I don't want simply to replace them all.

He intends to use the amp quite intensively as he works from home as a software developer and music helps him to concentrate. It does exactly the opposite for me!

Thanks

G6Tanuki · 1st Jun 2020, 8:34 pm

Aby chance of some photos?

In the 60s and 70s there were loads of 'plastic encapsulated' capacitors produced; RS offered a range of these (with grey encapsulation); Callins/TCC (in a green case) was another brand - and they do not age well.

jjl · 2nd Jun 2020, 8:53 am

I think that I know the type of cap you mean. They were used a lot in British mainframe computers of the '60s and '70s and are often branded Erie rather than Hunts - I believe that Erie took over Hunts some time in the late '60s.
They have some sort of plastic film dielectric and seem reliable - I harvested hundreds of them from scrap computer boards when I was an impoverished schoolboy and never found a bad one.

John

PaulR · 2nd Jun 2020, 9:21 am

Thanks for the replies.

Here are a couple of photos. They look nothing like the usual Hunts caps. In view of John's comments I think I will leave them alone for now. I was fortunate when I replaced the electrolytics as the pcb traces remained intact, but I think that these old ones are a bit fragile and I don't want to spoil what seems to have been a successful job.

dazzlevision · 2nd Jun 2020, 9:52 am

Yes, they are plastic film dielectric and reliable, apart from sometimes, the wire lead connection to the body failed.

Radiospares/RS Components used to sell them as their own brand and they had a grey outer sleeve.

PaulR · 2nd Jun 2020, 10:00 am

I did replace just two on the power supply board .... and one of the leads came off as I flexed it! I will send it back as it is.

Thanks

1st Jun 2020, 8:24 pm	#1
PaulR Dekatron Join Date: Oct 2003 Location: Southport Lancashire, UK. Posts: 3,233	Green Hunts Caps I have been overhauling an Armstrong 400 series receiver which my son bought recently. It is full of green Hunts capacitors, both electrolytic and lower value film ones of some sort. It was distorting at low frequencies and replacing all the electrolytics has cured this. That leaves the film ones. I know the reputation of Mouldseal caps but have never come across these later ones which seem to be encased in metal under the green plastic cover. Does anyone have any experience of the reliability of them? The amp appears to work ok and there are so many in the pre-amp boards in particular that I don't want simply to replace them all. He intends to use the amp quite intensively as he works from home as a software developer and music helps him to concentrate. It does exactly the opposite for me! Thanks __________________ Paul

1st Jun 2020, 8:34 pm	#2
G6Tanuki Dekatron Join Date: Apr 2012 Location: Wiltshire, UK. Posts: 13,996	Re: Green Hunts Caps Aby chance of some photos? In the 60s and 70s there were loads of 'plastic encapsulated' capacitors produced; RS offered a range of these (with grey encapsulation); Callins/TCC (in a green case) was another brand - and they do not age well.

2nd Jun 2020, 8:53 am	#3
jjl Octode Join Date: Jan 2003 Location: Ware, Herts. UK. Posts: 1,082	Re: Green Hunts Caps I think that I know the type of cap you mean. They were used a lot in British mainframe computers of the '60s and '70s and are often branded Erie rather than Hunts - I believe that Erie took over Hunts some time in the late '60s. They have some sort of plastic film dielectric and seem reliable - I harvested hundreds of them from scrap computer boards when I was an impoverished schoolboy and never found a bad one. John

2nd Jun 2020, 9:21 am	#4
PaulR Dekatron Join Date: Oct 2003 Location: Southport Lancashire, UK. Posts: 3,233	Re: Green Hunts Caps Thanks for the replies. Here are a couple of photos. They look nothing like the usual Hunts caps. In view of John's comments I think I will leave them alone for now. I was fortunate when I replaced the electrolytics as the pcb traces remained intact, but I think that these old ones are a bit fragile and I don't want to spoil what seems to have been a successful job. Attached Thumbnails __________________ Paul

2nd Jun 2020, 9:52 am	#5
dazzlevision Dekatron Join Date: Sep 2003 Location: Near Swindon, North Wiltshire, UK. Posts: 3,608	Re: Green Hunts Caps Yes, they are plastic film dielectric and reliable, apart from sometimes, the wire lead connection to the body failed. Radiospares/RS Components used to sell them as their own brand and they had a grey outer sleeve.

2nd Jun 2020, 10:00 am	#6
PaulR Dekatron Join Date: Oct 2003 Location: Southport Lancashire, UK. Posts: 3,233	Re: Green Hunts Caps I did replace just two on the power supply board .... and one of the leads came off as I flexed it! I will send it back as it is. Thanks __________________ Paul