Potential MPC74 Fukushima resistors GB for EUVL's FX5

[Horio]

I could use a new scope...kidding.

All I need from you guys is your patience. I'm just happy to help contribute to the F5X project, and help the people in Japan with our donation at the end of this GB.

 

[EUVL]

What to see how it looks like inside ?




Patrick

 

[Horio]

Oh that's cool.

FYI, I only have (200) 0R22 resistors left to measure!

 

[alazira]

Thanks EUVL,
Gives me some ideas, like eliminating the leads and soldering direct. Perhaps it would be possible to trim it to give the exact resistance one wanted?

 

[pmchoong]

What to see how it looks like inside ?




Patrick

Thanks. Which part of the F5X is this? Looks like a very tedious work.

 

[EUVL]

Fukushima MPC74 0R1.

 

[necplusultra]

Any update on the R matching?

Will these be sent out to individual buyers or packaged through the rest of the GB pertaining to the EUVL FX5 builds?

Reason is I only ordered these resistors and nothing else for the FX5.

regards.

 

[Horio]

The 0.22R resistors are matched, and grouped into sets of (8). The 0.47R matching should hopefully not take too much longer. The resistors are going to be sent through the regional distributors, along with the PRP resistors.

 

[necplusultra]

Thanks for the update Horio.

Who is the regional distributer for Canada?

 

[Horio]

That would be me.

 

[BigE]

Excellent work Horio!

When do you forsee the 0.22R resistors beign shipped?

 

[Horio]

We are getting close. Just a few more 0R47 resistors left to match, and then we will start getting things put together for shipping.

Thanks everyone for your patience, as it does take a while to match 2000 resistors at operating currents.

 

[BigE]

Thank you for all your hard work! It is very appreciated.

 

[chalkandtalk]

Seconded!!

 

[westsider1]

It may be too late for me to get in on this but I could really use quantity 6 of the MPC74 0R47 K - that is the one that is 0.1 ohm at low temperature and 1.0 ohm at high temperature. Would be using these to restore a vintage DC coupled audio amp.
The amp only uses 4 but I am feeling lucky that six would get me a couple of not-too-far-off matches...

 

[westsider1]

Read all previous posts - paid for quantity 8 of the 0R47 - keeping fingers crossed.

I am so very appreciative of the effort being made here. Thank-you all.

No one would even reply to an enquiry for small quantities. I tracked down the stocking distributor in Germany (previous post) but they were not responsive. All the clearance company has left are two other resistor values...

 

[Nikon1975]

Dear Westsider1,

I am not sure what you are saying about the resistance being 0.1 at low temperature and 1 at high temperature. I think this resistors are very stable at their value. If you cannot get them from the GB, I may help you, as I have some spares. From what I see the measured value is very consistent in the same batch, although they are rated 10 %

Davide

 

[westsider1]

Resistance Value

I was corrected by another astute member.
0.1 to 1.0 is the range of available resistor values.
E.g. 0.10 ohm, 1.2 ohm, 1.5 ohm, etc.

But these are positive temperature coefficent "thermistors" whose resistance increases with temperature.
So, e.g. 0R22 would be a value of 0.22 ohm at some test temperature or test current (e.g. 20C / or 1 amp) but the resistance then increases with current (as the temperature of the part increases).

 

[Nikon1975]

I think you are confusing. These are standard resistors, and keep their spec pretty well with temperature.

D.

 

[NicMac]

The MPC74 resistors have a Temp. coeff. of resistance specified to +/-350ppm/˚C.
I assume this means that their resistance may change up to 0.035% when the temperature is changed by on degree, or 3.5% for a change in temperature of 100˚C.
Definitely very lousy thermistors