Disgusting smell from radio chassis. - UK Vintage Radio Repair and Restoration Discussion Forum

Pete_kaye · 18th Apr 2008, 2:43 pm

I am stripping down an old 1935 TRF described elsewhere and was cleaning around the dropper and noticed a terrible smell-like dust,dirt and mouldy fish.Is it from the decaying dropper which has white asbestos centre?The cabinet smells fine inside.

Nickthedentist · 18th Apr 2008, 2:44 pm

The classic smelly thing in old radios is any failing selenium rectifier

Don't forget that dead mice occasionally turn up too

geofy · 18th Apr 2008, 2:47 pm

Could be from a selenium rectifier, these smell pretty gross when they fail.

Just don't breath in that asbestos dust.

Geof

Nickthedentist · 18th Apr 2008, 2:54 pm

Hang on, I'm sure selenuim recs weren't around in 1935... could be a replacement though, I suppose

BassoonBloke · 18th Apr 2008, 3:30 pm

Hi All,
just as a point of interest, i have a very early Ekco Radio at home (mains powered, 1930) and it uses a large long HW Selenium rectifier. So they were definately around.
Thinking about it my Pye Sunrise (E-AC 1932 i think) also uses a single, centre tapped selenium rectifier as a voltage doubler in its power supply.

And boy do they stink when they finally let go!! (think open case triplers in 1400 series tv's when they give up the ghost - Phew!!)

Cheers,
Alan.

BassoonBloke · 18th Apr 2008, 3:57 pm

You know i could be wrong about selenium rectifiers. According to a search on the web, they first appeared in 1933. Maybe i got a bit confuzzed, and was thinking of metal rectifiers - D'oh !!

Apologies,
Alan.

Darren-UK · 18th Apr 2008, 4:04 pm

What glue would've been used on the cabinet 70+ years ago? Would it have been made from animal-derived substances? I'm wondering if the radio's been exposed to damp and/or stored under certain conditions which have caused this glue to degrade and stink.

Aerodyne · 18th Apr 2008, 5:45 pm

I've not come across any type of metal oxide rectifier in a prewar radio that failed so as to cause a stink like the one mentioned here. Neither is the animal glue that most surely would have been used for cabinet assembly going to cause much smell. All in all, failing another more likely cause, the dead mouse/rat has it...
-Tony

Steve_P · 19th Apr 2008, 12:48 am

Take the Electrolytics out, and any non-valve diodes. If the dropper reads bad, chuck this too. Put the case, back and knobs in a bag with some cat litter for a week. Clean the chassis as much as you can, remove the valves and do the same with this. (Cat litter is great for absorbing nasty smalls.)

Remove, seal and dispose of any Asbestos.

Should shift it.

Cheers,

Steve P.

howard · 19th Apr 2008, 7:31 am

Hello,

It's sure smelly down here in Surrey ... I have a Hacker RP37A here which I'm sure was the target of a territorial tom cat and even two years after I restored it, it still stinks. Maybe cat litter will do the trick ... shame it wasn't available to the cat .....

Howard

Alan Stepney · 19th Apr 2008, 9:42 am

The great advantage of selenium rectifiers is that often you can detect when they are faulty from across the room.
None of this time wasting, removing the back, checking voltages, etc.

One quick whiff, and, "yes, I know whats wrong".

Aerodyne · 19th Apr 2008, 10:42 am

Alan is right, of course - with TV EHT rectifier tray elements, but I still maintain that I've not come across a selenium or other type of metal rectifier in a radio that has created anything like the stench of those old TV triplers and quadrupler trays. If anything, radio rectifiers seem to go high resistance and virtually stop working. Anyone know different?
-Tony

dave_n_t · 19th Apr 2008, 3:08 pm

Quote:

Originally Posted by Aerodyne

If anything, radio rectifiers seem to go high resistance and virtually stop working. Anyone know different?
-Tony

Well, in about 1973 I had a gram selenium rectifier go really bad

. (The gram was a Grundig job, with stereo s/e EL84 output). I was only into transistors then, so the obvious replacement using an encapsulated silicon bridge was right up my street. (Sadly, the gram eventually fell out of favour at home and while I was away at college was ditched

).

dave

Oldtimer74 · 19th Apr 2008, 7:27 pm

Warning. Selenium compounds are toxic if inhaled. I don`t have the latest data but in 1992 the limit for selenium compounds in air (other than hydrogen selenide which is only half as toxic) was 0.1 mg/cubic metre for long term exposure. short term exposure was not quoted.
If anything the limit now could be lower.
Don`t breathe the stuff!!
Pat

PJL · 19th Apr 2008, 7:43 pm

The heat from the dropper causes substantial airflow. Cigarette tar, coal tar, cooking oils all accumulate on the chassis around the dropper. Add water and you release some of those smells.

My guess anyway...

SPCh · 20th Apr 2008, 8:58 pm

My money's on the selenium rectifier:
the smell is almost unique in nature, and unforgettable.
(I've had the decomposing mice and tobacco smoke, but they don't come anywhere close -
from a servicing viewpoint, you change the rectifier without even bothering to find the Trader Sheet).

The only other place I've ever encountered it
(sorry, Moderators, too much info, I know, but not quite OT)
was when I had a tooth drilled to relieve the pressure on an abscessed nerve.

After 40 years I still haven't quite got rid of the taste !

Pete_kaye · 21st Apr 2008, 2:32 pm

Well that produced the biggest response I have ever had.

To clarify;the chassis was already out of the wooden case and wasn't damp.I was concerned that I was inhaling some poisonous fumes but I seem to be still here

. I will return to it soon.and I think I will wear a fume/dust mask.
I would post a copy of the smell but we haven't got the technology yet.

18th Apr 2008, 2:43 pm	#1
Pete_kaye Octode Join Date: Jun 2005 Location: Sheffield, South Yorkshire, UK. Posts: 1,227	Disgusting smell from radio chassis. I am stripping down an old 1935 TRF described elsewhere and was cleaning around the dropper and noticed a terrible smell-like dust,dirt and mouldy fish.Is it from the decaying dropper which has white asbestos centre?The cabinet smells fine inside.

18th Apr 2008, 2:44 pm	#2
Nickthedentist Dekatron Join Date: Jan 2005 Location: Oxford, UK. Posts: 17,846	Re: Disgusting smell The classic smelly thing in old radios is any failing selenium rectifier Don't forget that dead mice occasionally turn up too

18th Apr 2008, 2:47 pm	#3
geofy Retired Dormant Member Join Date: Jun 2006 Posts: 1,798	Re: Disgusting smell Could be from a selenium rectifier, these smell pretty gross when they fail. Just don't breath in that asbestos dust. Geof

18th Apr 2008, 2:54 pm	#4
Nickthedentist Dekatron Join Date: Jan 2005 Location: Oxford, UK. Posts: 17,846	Re: Disgusting smell Hang on, I'm sure selenuim recs weren't around in 1935... could be a replacement though, I suppose

18th Apr 2008, 3:30 pm	#5
BassoonBloke Pentode Join Date: Feb 2006 Location: East London, UK. Posts: 231	Re: Disgusting smell Hi All, just as a point of interest, i have a very early Ekco Radio at home (mains powered, 1930) and it uses a large long HW Selenium rectifier. So they were definately around. Thinking about it my Pye Sunrise (E-AC 1932 i think) also uses a single, centre tapped selenium rectifier as a voltage doubler in its power supply. And boy do they stink when they finally let go!! (think open case triplers in 1400 series tv's when they give up the ghost - Phew!!) Cheers, Alan.

18th Apr 2008, 3:57 pm	#6
BassoonBloke Pentode Join Date: Feb 2006 Location: East London, UK. Posts: 231	Re: Disgusting smell You know i could be wrong about selenium rectifiers. According to a search on the web, they first appeared in 1933. Maybe i got a bit confuzzed, and was thinking of metal rectifiers - D'oh !! Apologies, Alan.

18th Apr 2008, 4:04 pm	#7
Darren-UK Retired Dormant Member Join Date: Apr 2003 Location: Blackpool, Lancashire, UK. Posts: 4,061	Re: Disgusting smell What glue would've been used on the cabinet 70+ years ago? Would it have been made from animal-derived substances? I'm wondering if the radio's been exposed to damp and/or stored under certain conditions which have caused this glue to degrade and stink.

18th Apr 2008, 5:45 pm	#8
Aerodyne Octode Join Date: Jun 2004 Location: Hampton Vale, Peterborough, UK. Posts: 1,698	Re: Disgusting smell I've not come across any type of metal oxide rectifier in a prewar radio that failed so as to cause a stink like the one mentioned here. Neither is the animal glue that most surely would have been used for cabinet assembly going to cause much smell. All in all, failing another more likely cause, the dead mouse/rat has it... -Tony

19th Apr 2008, 12:48 am	#9
Steve_P Dekatron Join Date: Sep 2003 Location: Bolton, Greater Manchester, UK. Posts: 6,644	Re: Disgusting smell Take the Electrolytics out, and any non-valve diodes. If the dropper reads bad, chuck this too. Put the case, back and knobs in a bag with some cat litter for a week. Clean the chassis as much as you can, remove the valves and do the same with this. (Cat litter is great for absorbing nasty smalls.) Remove, seal and dispose of any Asbestos. Should shift it. Cheers, Steve P. __________________ If we've always had it, why is the Car Boot open? You're not sneaking another Old TV in are you...?

19th Apr 2008, 7:31 am	#10
howard Nonode Join Date: May 2005 Location: Godalming, Surrey, UK. Posts: 2,593	Re: Disgusting smell Hello, It's sure smelly down here in Surrey ... I have a Hacker RP37A here which I'm sure was the target of a territorial tom cat and even two years after I restored it, it still stinks. Maybe cat litter will do the trick ... shame it wasn't available to the cat ..... Howard

19th Apr 2008, 9:42 am	#11
Alan Stepney Rest in Peace Join Date: Feb 2008 Location: Dorset, UK. Posts: 947	Re: Disgusting smell The great advantage of selenium rectifiers is that often you can detect when they are faulty from across the room. None of this time wasting, removing the back, checking voltages, etc. One quick whiff, and, "yes, I know whats wrong".

19th Apr 2008, 10:42 am	#12
Aerodyne Octode Join Date: Jun 2004 Location: Hampton Vale, Peterborough, UK. Posts: 1,698	Re: Disgusting smell Alan is right, of course - with TV EHT rectifier tray elements, but I still maintain that I've not come across a selenium or other type of metal rectifier in a radio that has created anything like the stench of those old TV triplers and quadrupler trays. If anything, radio rectifiers seem to go high resistance and virtually stop working. Anyone know different? -Tony

19th Apr 2008, 7:27 pm	#14
Oldtimer74 Rest in Peace Join Date: Apr 2008 Location: Worcester, Worcestershire, UK. Posts: 330	Re: Disgusting smell Warning. Selenium compounds are toxic if inhaled. I don`t have the latest data but in 1992 the limit for selenium compounds in air (other than hydrogen selenide which is only half as toxic) was 0.1 mg/cubic metre for long term exposure. short term exposure was not quoted. If anything the limit now could be lower. Don`t breathe the stuff!! Pat

19th Apr 2008, 7:43 pm	#15
PJL Dekatron Join Date: Sep 2005 Location: Seaford, East Sussex, UK. Posts: 5,997	Re: Disgusting smell The heat from the dropper causes substantial airflow. Cigarette tar, coal tar, cooking oils all accumulate on the chassis around the dropper. Add water and you release some of those smells. My guess anyway...

20th Apr 2008, 8:58 pm	#16
SPCh Rest in Peace Join Date: Nov 2004 Location: Antwerp, Belgium Posts: 345	Re: Disgusting smell My money's on the selenium rectifier: the smell is almost unique in nature, and unforgettable. (I've had the decomposing mice and tobacco smoke, but they don't come anywhere close - from a servicing viewpoint, you change the rectifier without even bothering to find the Trader Sheet). The only other place I've ever encountered it (sorry, Moderators, too much info, I know, but not quite OT) was when I had a tooth drilled to relieve the pressure on an abscessed nerve. After 40 years I still haven't quite got rid of the taste !

21st Apr 2008, 2:32 pm	#17
Pete_kaye Octode Join Date: Jun 2005 Location: Sheffield, South Yorkshire, UK. Posts: 1,227	Re: Disgusting smell Well that produced the biggest response I have ever had.To clarify;the chassis was already out of the wooden case and wasn't damp.I was concerned that I was inhaling some poisonous fumes but I seem to be still here. I will return to it soon.and I think I will wear a fume/dust mask. I would post a copy of the smell but we haven't got the technology yet.