round attenuator dissasembly?


militaryoperator
 

Does anyone know how to take apart a round attenuator? I have a Weinschel 50W one faulty.

Thought I'd try and look inside. 

Looks like the fins screw off the body?

Ben.


militaryoperator
 

To answer my own question.  The ends unscrew from the body, watch you don't loose little spring and gold plunger.

Metal tube inside finned outer. Slice of ceramic inside metal tube, tight push-fit, with integrated film R's not smd, so impossible to repair.

Options: make replacement slice with very flat smd r's or even with holes in slice so r can sit flush, several r's in series parallel to handle power. 

Will have lost higher freq facility though I guess but should be good to Ghz or so.

Ben.



-----Original Message-----

Subject: [UKMicrowaves] round attenuator dissasembly?

Does anyone know how to take apart a round attenuator? I have a Weinschel 50W one faulty.
Thought I'd try and look inside. 
Looks like the fins screw off the body?
Ben.


Graham G3VKV
 

Take care Ben,
from their catalogue   Graham G3VKV

Most Aeroflex / Weinschel products contain beryllium oxide substrate. DO NOT sand, scrap or tamper with this substrate in any way. For more information about beryllium oxide or disposal, refer to the Material Safety Data Sheet or contact Aeroflex / Weinschel. 


militaryoperator
 


Take care Ben,
from their catalogue   Graham G3VKV

Most Aeroflex / Weinschel products contain beryllium oxide substrate. DO NOT sand, scrap or tamper with this substrate in any way. For more information about beryllium oxide or disposal, refer to the Material Safety Data Sheet or contact Aeroflex / Weinschel. 



Bugger. Too late Graham. 

Ben. 


militaryoperator
 

Take care Ben,
from their catalogue   Graham G3VKV

Most Aeroflex / Weinschel products contain beryllium oxide substrate. DO NOT sand, scrap or tamper with this substrate in any way. For more information about beryllium oxide or disposal, refer to the Material Safety Data Sheet or contact Aeroflex / Weinschel. 


They said:

Hello…. SN: BH2917 was MFR 8/04/1999 – unit is almost 23 years old.  This would be a non-repairable due to its age.
 With  Regards, Customer Relations Specialist, Weinschel.

As the small slice looks futuristic for 1999 I wonder how they fit them now?

So, have a nice cylindrical heatsink should  I need such !!

Ben


Andy
 

Use it quickly before the Berylliosis kills you off 🙂


From: UKMicrowaves@groups.io <UKMicrowaves@groups.io> on behalf of militaryoperator via groups.io <Military1944@...>
Sent: Friday, January 29, 2021 4:51 AM
To: UKMicrowaves@groups.io <UKMicrowaves@groups.io>
Subject: Re: [UKMicrowaves] round attenuator dissasembly?
 
Take care Ben,
from their catalogue   Graham G3VKV

Most Aeroflex / Weinschel products contain beryllium oxide substrate. DO NOT sand, scrap or tamper with this substrate in any way. For more information about beryllium oxide or disposal, refer to the Material Safety Data Sheet or contact Aeroflex / Weinschel. 


They said:

Hello…. SN: BH2917 was MFR 8/04/1999 – unit is almost 23 years old.  This would be a non-repairable due to its age.
 With  Regards, Customer Relations Specialist, Weinschel.

As the small slice looks futuristic for 1999 I wonder how they fit them now?

So, have a nice cylindrical heatsink should  I need such !!

Ben


John Fell
 

Ben,
I could be wrong , but when I opened up an O/C inline 1W rated pad from a junk bin  I found the sputter deposited /laser trimmed resistive elements had more or less vapourised .
However the R was deposited on thin ceramic substrate and that was retained along the long edges with what looked like Beryllium foil .Very tight /more or less impossible to get out without cracking the ceramic .
So basically do not cut/file or swallow the foil bits and you should live to enjoy the RF 'speriments you are doing .
73
John
G0API

On Fri, 29 Jan 2021 at 12:51, militaryoperator via groups.io <Military1944=aol.com@groups.io> wrote:
Take care Ben,
from their catalogue   Graham G3VKV

Most Aeroflex / Weinschel products contain beryllium oxide substrate. DO NOT sand, scrap or tamper with this substrate in any way. For more information about beryllium oxide or disposal, refer to the Material Safety Data Sheet or contact Aeroflex / Weinschel. 


They said:

Hello…. SN: BH2917 was MFR 8/04/1999 – unit is almost 23 years old.  This would be a non-repairable due to its age.
 With  Regards, Customer Relations Specialist, Weinschel.

As the small slice looks futuristic for 1999 I wonder how they fit them now?

So, have a nice cylindrical heatsink should  I need such !!

Ben


militaryoperator
 

Ben,
I could be wrong , but when I opened up an O/C inline 1W rated pad from a junk bin  I found the sputter deposited /laser trimmed resistive elements had more or less vapourised .
However the R was deposited on thin ceramic substrate and that was retained along the long edges with what looked like Beryllium foil .Very tight /more or less impossible to get out without cracking the ceramic .
So basically do not cut/file or swallow the foil bits and you should live to enjoy the RF 'speriments you are doing .
73
John
G0API



Sounds exactly the same as this one John. 

I have kept the gold edge trimmings, I thought I might be able to make a replacement slice, maybe with cutouts and sma R's inserted etc. 

Give me something to do whilst going up the walls. 

Ben G4BXD


Graham G3VKV
 

Ben,
I would read this instead only 166 pages -  and look on the auction site for a new attenuator.

Communicating Health Risks Working Safely with Beryllium (energy.gov)

Graham G3VKV


Andy G4JNT
 

Even back in the 1970s - 80s they were making a big fuss about it.   My Mother was an occupational health nurse at the old Austin-Rover Longbridge plant and I remember her talking about the Beryllia kit they had on standby.   Quite where the substance would have been used in the motor industry I don't know, but she certainly got all perturbed seeing the "Warning Contains BeO" sign on one of my packages. 

Andy


On Fri, 29 Jan 2021 at 21:46, Graham G3VKV via groups.io <g3vkv=btinternet.com@groups.io> wrote:
Ben,
I would read this instead only 166 pages -  and look on the auction site for a new attenuator.

Communicating Health Risks Working Safely with Beryllium (energy.gov)

Graham G3VKV


alwyn.seeds1
 

Dear All,

The very common hazards in electronics are BeO thermal links and Beryllium Copper alloys used in spring stock and in RF vacuum device construction.

Eimac Varian used to include BeO hazard sheets with most of their valves and I remember long debates as to whether the insulating seals in 4CX250Bs were Beryllium Oxide- I think it was decided that they were not, though the thermal links of conduction cooled versions were. External anodes frequently used Beryllium Copper for better machining- machinists often suffered from lung disease, though it may have been incorrectly attributed to smoking.

Lots of RF power transistors from the 1960s to the 1980s used BeO packaging for better heat conductivity and RF attenuators/loads frequently deposit the resistive element on BeO, again for better heat conductivity.

So I would not dismantle a BeO containing device and would be careful cutting up old valves which may contain a variety of toxic substances as well as the Beryllium Copper hazard.

Those who worked in the manufacturers would know more.

Regards,

Alwyn G8DOH

   
_____________________________________________________

Alwyn Seeds, Director
SynOptika Ltd.,
114 Beaufort Street,
London,
SW3 6BU,
England.


SynOptika Ltd., Registered in England and Wales: No. 04606737
Registered Office: 114 Beaufort Street, London, SW3 6BU, United Kingdom.
_____________________________________________________


Robin Szemeti - G1YFG
 

While I would agree with you that Be Oxide is nasty stuff, beryl copper is relatively benign and has been used for non-sparking hand tools for many decades without issue. It can safely be cut and drilled without risk, although you may not want to sand it.

On Sat, 30 Jan 2021 at 12:14, alwyn.seeds1 <a.seeds@...> wrote:
Dear All,

The very common hazards in electronics are BeO thermal links and Beryllium Copper alloys used in spring stock and in RF vacuum device construction.

Eimac Varian used to include BeO hazard sheets with most of their valves and I remember long debates as to whether the insulating seals in 4CX250Bs were Beryllium Oxide- I think it was decided that they were not, though the thermal links of conduction cooled versions were. External anodes frequently used Beryllium Copper for better machining- machinists often suffered from lung disease, though it may have been incorrectly attributed to smoking.

Lots of RF power transistors from the 1960s to the 1980s used BeO packaging for better heat conductivity and RF attenuators/loads frequently deposit the resistive element on BeO, again for better heat conductivity.

So I would not dismantle a BeO containing device and would be careful cutting up old valves which may contain a variety of toxic substances as well as the Beryllium Copper hazard.

Those who worked in the manufacturers would know more.

Regards,

Alwyn G8DOH

   
_____________________________________________________

Alwyn Seeds, Director
SynOptika Ltd.,
114 Beaufort Street,
London,
SW3 6BU,
England.


SynOptika Ltd., Registered in England and Wales: No. 04606737
Registered Office: 114 Beaufort Street, London, SW3 6BU, United Kingdom.
_____________________________________________________


--
Robin Szemeti - G1YFG


alwyn.seeds1
 

Dear Robin,

One of the founders of Varian, who did a lot of BeCu turning at Stanford, died prematurely of Be lung damage.

I suppose it’s all a matter of how much exposure and your susceptibility.

Regards,

Alwyn
_____________________________________________________

Alwyn Seeds, Director
SynOptika Ltd.,
114 Beaufort Street,
London,
SW3 6BU,
England.


SynOptika Ltd., Registered in England and Wales: No. 04606737
Registered Office: 114 Beaufort Street, London, SW3 6BU, United Kingdom.
_____________________________________________________


Robin Szemeti - G1YFG
 

Yep, I suspect a long term occupational exposure is not good ... but for the stuff amateurs are likely to do its not an issue, but a well made cautionary point.   The Be Oxide however is very much worth avoiding, even in small quantities. We had specific disposal routes for damaged BeO containing devices when I was at the beeb.



On Sat, 30 Jan 2021 at 16:12, alwyn.seeds1 <a.seeds@...> wrote:
Dear Robin,

One of the founders of Varian, who did a lot of BeCu turning at Stanford, died prematurely of Be lung damage.

I suppose it’s all a matter of how much exposure and your susceptibility.

Regards,

Alwyn
_____________________________________________________

Alwyn Seeds, Director
SynOptika Ltd.,
114 Beaufort Street,
London,
SW3 6BU,
England.


SynOptika Ltd., Registered in England and Wales: No. 04606737
Registered Office: 114 Beaufort Street, London, SW3 6BU, United Kingdom.
_____________________________________________________


--
Robin Szemeti - G1YFG