Difference between revisions of "N2PK VNA"
From Note to self
(→Missing) |
(→Missing) |
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* C213, C290 100nF X7R | * C213, C290 100nF X7R | ||
* C280,281,292 | * C280,281,292 | ||
| + | ==== Top side ==== | ||
| + | * C251 100nF X7R | ||
| + | * Q190,270: npn tx | ||
| + | * C125: 1uF 25V X7R 10% | ||
=== Questions === | === Questions === | ||
* All caps seem to be NPO, X7R, X5R, or Tant. NPO = temperature independant, X7R & X5R = ceramic, Tant = tantalum. Problem: I only have an assortment, no other specs (prob. ceramic?)... | * All caps seem to be NPO, X7R, X5R, or Tant. NPO = temperature independant, X7R & X5R = ceramic, Tant = tantalum. Problem: I only have an assortment, no other specs (prob. ceramic?)... | ||
* R160a - R166a should be 221K. They are part of (what I assume to be) an RC filter, and a load for that filter (the input impedance of that buffer IC is probably quite high). These are digital lines. I don't have those values, so I was thinking about taking 1k2/75pF for the RC filter, and 270k for the load. I don't see why it should be very critical. | * R160a - R166a should be 221K. They are part of (what I assume to be) an RC filter, and a load for that filter (the input impedance of that buffer IC is probably quite high). These are digital lines. I don't have those values, so I was thinking about taking 1k2/75pF for the RC filter, and 270k for the load. I don't see why it should be very critical. | ||
Revision as of 01:25, 16 October 2013
Contents
Documentation
Notes
Components
Missing
Bottom side
- R160a - R166a: I used 270k instead of 220k
- C115-117,126,127: 10uF 16V X5R 1210
- C180-C184
- C170-C174
- R250: 3.3R 5% 0805 - I have 1.8R, 3.9R
- C250, 280,281,292: 10uF 16V Tant 20%
- C213, C290 100nF X7R
- C280,281,292
Top side
- C251 100nF X7R
- Q190,270: npn tx
- C125: 1uF 25V X7R 10%
Questions
- All caps seem to be NPO, X7R, X5R, or Tant. NPO = temperature independant, X7R & X5R = ceramic, Tant = tantalum. Problem: I only have an assortment, no other specs (prob. ceramic?)...
- R160a - R166a should be 221K. They are part of (what I assume to be) an RC filter, and a load for that filter (the input impedance of that buffer IC is probably quite high). These are digital lines. I don't have those values, so I was thinking about taking 1k2/75pF for the RC filter, and 270k for the load. I don't see why it should be very critical.
