Re: Tek 2215

Tothwolf
 

On Mon, 25 Jan 2016, David @DWH [TekScopes] wrote:

The replacements were physically smaller than the original parts. I
thought Tektronix might have selected the originals for good RF
performance but other than size, they are the same series of film
resistors used throughout the rest of the oscilloscope and a transient
response test showed that the new physically smaller replacements
worked fine.

I did not check it before since I did not have more than one resistor
to select from but the Dale MFF series datasheet says "very good high
frequency characteristics" for whatever that is worth:

http://www.33audio.com/enter/data/DaleFilmpart2.pdf
I believe I found them. They are actually the same Vishay/Dale CCF series I was going to use for R398 and R399, although it appears I inadvertently ordered 15 ohm instead of 51 ohm for those two (good thing I only purchased 10), so I guess those are going on the next parts order.

R378,R379,R388,R389 340 ohm 1% 1/2W metal film Dale MFF1226G340R0F

Replace with Vishay/Dale CCF60340RFKE36

R398,R399 51 ohm 5% 1/2W carbon comp Allen-Bradley EB5105

Replace with Vishay/Dale CCF6051R1FKE36 (51.1ohm, but close enough ;)

Join TekScopes@groups.io to automatically receive all group messages.