A long time since looking at such a radio
to check-over/repair as no known history and not powered up in any way
http://home.graffiti.net/diverse:graffiti.net/cr280.jpg
Took apart section by section with bits in separate labelled bags
I will test the valves later today
ECH42, EF41, EBC41,EL42
Seems surprisingly good condition inside. Will have to replace the 12V (-ve
supply) lead and speaker lead as perished and the on/off switch is ohmic.
The vibrator had obviously been removed at some point (putty-stuff is split)
in the past. what to look out for when testing these and how to remove that
putty-like goo if necessary, warming with hot-air?. I assume test with load
attached but what to do if a problem within the vibrator.?

What ohmage speaker? 2.5, 3 or 4 ohm ?
Could measure primary R of the output matcher more accurately if any help
but primary 692 ohm and secondary between 0.1 and 0.2 ohm

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

3 of the valves tested fine but the ECH42 was very C/H leaky but I happened
to
have one of these valves lying around

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

On 2008-06-14, N_Cook wrote:
....
The vibrator had obviously been removed at some point (putty-stuff is split)
in the past. what to look out for when testing these and how to remove that
putty-like goo if necessary, warming with hot-air?. I assume test with load
attached but what to do if a problem within the vibrator.?
....

I doubt there's much chance of finding a replacement vibrator these
days, if its contacts have gone. I wonder if anyone has come up with
a design for a solid-state (plug compatible) replacement?

Mike.

Remove _ for valid address wrote in message
...
On 2008-06-14, N_Cook wrote:
...
The vibrator had obviously been removed at some point (putty-stuff is
split)
in the past. what to look out for when testing these and how to remove
that
putty-like goo if necessary, warming with hot-air?. I assume test with
load
attached but what to do if a problem within the vibrator.?
...

I doubt there's much chance of finding a replacement vibrator these
days, if its contacts have gone. I wonder if anyone has come up with
a design for a solid-state (plug compatible) replacement?

Mike.

I have some schema for similar Ekco CR... radios and the vibrator would seem
to contain a valve or 2 inside as well as coil and bell-mechanism.

If you can get inside the can , do they have oil or anything inside ? under
that goo would there be a contact adjustment aperture ?
A long time ago I seem to remember trying to deal with one where the contact
make-break was very irregular and I never could make it work properly


--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

"N_Cook" wrote in message
...
Remove _ for valid address wrote in message
...
On 2008-06-14, N_Cook wrote:
...
The vibrator had obviously been removed at some point (putty-stuff is
split)
in the past. what to look out for when testing these and how to remove
that
putty-like goo if necessary, warming with hot-air?. I assume test with
load
attached but what to do if a problem within the vibrator.?
...

I doubt there's much chance of finding a replacement vibrator these
days, if its contacts have gone. I wonder if anyone has come up with
a design for a solid-state (plug compatible) replacement?

Mike.

I have some schema for similar Ekco CR... radios and the vibrator would seem
to contain a valve or 2 inside as well as coil and bell-mechanism.

If you can get inside the can , do they have oil or anything inside ? under
that goo would there be a contact adjustment aperture ?
A long time ago I seem to remember trying to deal with one where the contact
make-break was very irregular and I never could make it work properly


--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/


There are no adjustments inside a vibrator. No oil. The "putty-stuff" that you
saw is likely to be an asphalt or tarry substance used to seal the mechanism
from outside air. Vibrators were purged and filled with nitrogen to reduce the
possibility of oxidation of the contacts.

If you can open the vibrator casing, and get to the innards, you might be able
to repair the contacts (if that's the problem) and reseal with epoxy. Not much
else to go wrong inside, other than the coil burning out. Oh yeah, the leafs
that the contacts are on might lose their temper (springiness) and cause the
contacts to have inadequate contact pressure. If that happens, the vibrator is
wasted.

There are still sources for vibrators (not cheap!!!).
http://www.turnswitch.com/radio1.htm

Antique Electronics Supply (http://www.tubesandmore.com/) has solid state
replacements for $30 USD.

--
Dave M
MasonDG44 at comcast dot net (Just substitute the appropriate characters in the
address)

Experience: What you get when you don't get what you want

On 2008-06-15, N_Cook wrote:
Remove _ for valid address wrote in message
...
On 2008-06-14, N_Cook wrote:
...
The vibrator had obviously been removed at some point
(putty-stuff is split)
in the past. what to look out for when testing these and how
to remove that
putty-like goo if necessary, warming with hot-air?.
I assume test with load
attached but what to do if a problem within the vibrator.?
...

I doubt there's much chance of finding a replacement vibrator these
days, if its contacts have gone. I wonder if anyone has come up with
a design for a solid-state (plug compatible) replacement?

Mike.

I have some schema for similar Ekco CR... radios and the vibrator would seem
to contain a valve or 2 inside as well as coil and bell-mechanism.

If you can get inside the can , do they have oil or anything inside ? under
that goo would there be a contact adjustment aperture ?
A long time ago I seem to remember trying to deal with one where the contact
make-break was very irregular and I never could make it work properly

I've only ever taken one radio vibrator apart. It looks just like
a small relay inside a soundproofed can (foam inside). There's a mass
sprung on the arm, to make it mechanically resonant, plus two
changeover contacts and one contact in series with the coil.
Total 6 connections (one terminal is common on both changeover
contacts and the contact in series with the coil.

There is a mechanical adjustment screw for the NC contact to the coil.

It has no "goo" or "oil" or anything like that, just a crimp at the
bottom of the can onto the paxolin base on which the pins mount.
Surprisingly, the foam rubber stuff looks as good as new, this
one must be at least 50 years old. I could imagine some other
rubber compositions could turn to "goo" by now.

Mike.

On Jun 15, 6:35*pm, "DaveM" wrote:
"N_Cook" wrote in message

...





Remove _ for valid address wrote in message
...
On 2008-06-14, N_Cook wrote:
...
The vibrator had obviously been removed at some point (putty-stuff is
split)
in the past. what to look out for when testing these and how to remove
that
putty-like goo if necessary, warming with hot-air?. I assume test with
load
attached but what to do if a problem within the vibrator.?
...

I doubt there's much chance of finding a replacement vibrator these
days, if its contacts have gone. I wonder if anyone has come up with
a design for a solid-state (plug compatible) replacement?

Mike.

I have some schema for similar Ekco CR... radios and the vibrator would seem
to contain a valve or 2 inside as well as coil and bell-mechanism.

If you can get inside the can , do they have oil or anything inside ? under
that goo would there be a contact adjustment aperture ?
A long time ago I seem to remember trying to deal with one where the contact
make-break was very irregular and I never could make it work properly

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

There are no adjustments inside a vibrator. *No oil. *The "putty-stuff" that you
saw is likely to be an asphalt or tarry substance used to seal the mechanism
from outside air. *Vibrators were purged and filled with nitrogen to reduce the
possibility of oxidation of the contacts.


Many vibrators have adjusting screws inside them.




If you can open the vibrator casing, and get to the innards, you might be able
to repair the contacts (if that's the problem) and reseal with epoxy. *Not much
else to go wrong inside, other than the coil burning out. *Oh yeah, the leafs
that the contacts are on might lose their temper (springiness) and cause the
contacts to have inadequate contact pressure. *If that happens, the vibrator is
wasted.

There are still sources for vibrators (not cheap!!!).http://www.turnswitch..com/radio1.htm

Antique Electronics Supply (http://www.tubesandmore.com/) has solid state
replacements for $30 USD.

--
Dave M
MasonDG44 at comcast dot net *(Just substitute the appropriate characters in the
address)

Experience: What you get when you don't get what you want- Hide quoted text -

- Show quoted text -

"sparky" wrote in message
...
On Jun 15, 6:35 pm, "DaveM" wrote:
"N_Cook" wrote in message

...





Remove _ for valid address wrote in message
...
On 2008-06-14, N_Cook wrote:
...
The vibrator had obviously been removed at some point (putty-stuff is
split)
in the past. what to look out for when testing these and how to remove
that
putty-like goo if necessary, warming with hot-air?. I assume test with
load
attached but what to do if a problem within the vibrator.?
...

I doubt there's much chance of finding a replacement vibrator these
days, if its contacts have gone. I wonder if anyone has come up with
a design for a solid-state (plug compatible) replacement?

Mike.

I have some schema for similar Ekco CR... radios and the vibrator would seem
to contain a valve or 2 inside as well as coil and bell-mechanism.

If you can get inside the can , do they have oil or anything inside ? under
that goo would there be a contact adjustment aperture ?
A long time ago I seem to remember trying to deal with one where the contact
make-break was very irregular and I never could make it work properly

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

There are no adjustments inside a vibrator. No oil. The "putty-stuff" that you
saw is likely to be an asphalt or tarry substance used to seal the mechanism
from outside air. Vibrators were purged and filled with nitrogen to reduce the
possibility of oxidation of the contacts.


Many vibrators have adjusting screws inside them.


Yes.. absolutely correct.. Been so long since I've been inside a vibrator I
had forgotten.

--
Dave M
MasonDG44 at comcast dot net (Just substitute the appropriate characters in the
address)

Experience: What you get when you don't get what you want

In article ,
says...


Very poor selection of solid state vibrators at Antique Electronics Supply
better to go to the people that actually make them. They have pin out diagrams
and all sorts of these things available.

http://www.radiosforoldcars.com/

Or Direct to the vibrator page.

http://www.radiosforoldcars.com/vibratorsF.htm


John k9uwa