Searching for thermistors to repair a uW power meter


DD1US
 

Dear all,

 

I have here an old power meter which was apparently built according to a description of Carsten Vieland DJ4GC.

 

It uses the principle of a bolometer.

 

Unfortunately, the thermistors are defective and I need to replace them.

 

They are apparently of the following type: Siemens NTC type K19 nominal 12kOhms

 

Does anyone here in the group have a pair (or two in case something goes wrong during the repair action) of

such thermistors which he would be willing to sell ?

 

Also if someone knows a shop etc where to buy them a hint would be appreciated.

 

Many thanks in advance for your answers.

 

Kind regards

 

Matthias

 

www.dd1us.de

 


Greg - ZL3IX
 

If you manage to find some, please let me know, Matthias. A couple of years ago I tried to find a pair of these thermistors to make a DJ4GC power meter, but I was unsuccessful. I don't believe they are made any more.


Robin Szemeti - G1YFG
 

Could you notuse surface mount types?  There are many electrically similar devices intiny packages .. if you can mount them ...


On Wed, 24 Feb 2021 at 18:33, Greg - ZL3IX <zl3ix@...> wrote:
If you manage to find some, please let me know, Matthias. A couple of years ago I tried to find a pair of these thermistors to make a DJ4GC power meter, but I was unsuccessful. I don't believe they are made any more.


--
Robin Szemeti - G1YFG


DF6NA Rainer
 

Hallo Matthias,

irre ich mich oder waren das nicht Dioden die DJ4GC verwendet hat ???

73, Rainer


Am 24.02.2021 um 13:47 schrieb DD1US:

Dear all,

 

I have here an old power meter which was apparently built according to a description of Carsten Vieland DJ4GC.

 

It uses the principle of a bolometer.

 

Unfortunately, the thermistors are defective and I need to replace them.

 

They are apparently of the following type: Siemens NTC type K19 nominal 12kOhms

 

Does anyone here in the group have a pair (or two in case something goes wrong during the repair action) of

such thermistors which he would be willing to sell ?

 

Also if someone knows a shop etc where to buy them a hint would be appreciated.

 

Many thanks in advance for your answers.

 

Kind regards

 

Matthias

 

www.dd1us.de

 



DD1US
 

Hello Rainer,

 

Yes, as I mentioned that should be the power meter as designed by Carsten Vieland DJ4GC.

 

Do you have some of them left or know a source ?

 

Kind regards

 

Matthias

 

www.dd1us.de

 

 

Von: UKMicrowaves@groups.io <UKMicrowaves@groups.io> Im Auftrag von DF6NA Rainer
Gesendet: Mittwoch, 24. Februar 2021 20:15
An: UKMicrowaves@groups.io
Betreff: Re: [UKMicrowaves] Searching for thermistors to repair a uW power meter

 

Hallo Matthias,

irre ich mich oder waren das nicht Dioden die DJ4GC verwendet hat ???

73, Rainer


Am 24.02.2021 um 13:47 schrieb DD1US:

Dear all,

 

I have here an old power meter which was apparently built according to a description of Carsten Vieland DJ4GC.

 

It uses the principle of a bolometer.

 

Unfortunately, the thermistors are defective and I need to replace them.

 

They are apparently of the following type: Siemens NTC type K19 nominal 12kOhms

 

Does anyone here in the group have a pair (or two in case something goes wrong during the repair action) of

such thermistors which he would be willing to sell ?

 

Also if someone knows a shop etc where to buy them a hint would be appreciated.

 

Many thanks in advance for your answers.

 

Kind regards

 

Matthias

 

www.dd1us.de

 

 


DD1US
 

Hi Greg,

 

Ok, will do.

 

Kind regards

 

Matthias

 

www.dd1us.de

 

 

Von: UKMicrowaves@groups.io <UKMicrowaves@groups.io> Im Auftrag von Greg - ZL3IX
Gesendet: Mittwoch, 24. Februar 2021 19:33
An: UKMicrowaves@groups.io
Betreff: Re: [UKMicrowaves] Searching for thermistors to repair a uW power meter

 

If you manage to find some, please let me know, Matthias. A couple of years ago I tried to find a pair of these thermistors to make a DJ4GC power meter, but I was unsuccessful. I don't believe they are made any more.


DD1US
 

Hi Robin,

 

Possibly.

 

The challenge is to thermally isolate the detector from unwanted influeces.

 

The K19 is very nice in this respect with a diameter of only 0.4mm and very thin leads.

 

Regards

 

Matthias

 

www.dd1us.de

 

 

Von: UKMicrowaves@groups.io <UKMicrowaves@groups.io> Im Auftrag von Robin Szemeti - G1YFG
Gesendet: Mittwoch, 24. Februar 2021 20:08
An: UKMicrowaves@groups.io
Betreff: Re: [UKMicrowaves] Searching for thermistors to repair a uW power meter

 

Could you notuse surface mount types?  There are many electrically similar devices intiny packages .. if you can mount them ...

 

 

On Wed, 24 Feb 2021 at 18:33, Greg - ZL3IX <zl3ix@...> wrote:

If you manage to find some, please let me know, Matthias. A couple of years ago I tried to find a pair of these thermistors to make a DJ4GC power meter, but I was unsuccessful. I don't believe they are made any more.


--
Robin Szemeti - G1YFG