Difference between revisions of "N2PK VNA"
From Note to self
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| + | == Master oscillator == | ||
| + | I'm going to build the master oscillator from a Winner-Confield oscillator. Output needs to be adapted to 5V. | ||
| + | |||
| + | === Parts === | ||
| + | * CW470CT-ND Winner Confield oscillator | ||
| + | * TC1014-3.3VCT713CT-ND Microchip 3.3V Regulator | ||
| + | * MMBTH10-FDICT-ND (.28€) of KST10MTFCT-ND (0.18€) -> First one has a much larger stock. Is there something I am missing about the cheaper model? | ||
| + | * some caps and inductors for filtering 5V | ||
| + | * some resistors | ||
| + | |||
== Documentation == | == Documentation == | ||
* [http://n2pk.com/VNA/VNAarch.html How it works] | * [http://n2pk.com/VNA/VNAarch.html How it works] | ||
| Line 14: | Line 24: | ||
* C180, C170: 27pF (filter redesign) | * C180, C170: 27pF (filter redesign) | ||
| − | * R250: 3.3R 5% 0805 - I have 1.8R, 3.9R | + | * R250: 3.3R 5% 0805 - I have 1.8R, 3.9R -> Use 3.9 |
* C250, 280,281,292: 10uF 16V Tant 20% | * C250, 280,281,292: 10uF 16V Tant 20% | ||
* C213, C290 100nF X7R | * C213, C290 100nF X7R | ||
Revision as of 23:45, 19 October 2013
Contents
Master oscillator
I'm going to build the master oscillator from a Winner-Confield oscillator. Output needs to be adapted to 5V.
Parts
- CW470CT-ND Winner Confield oscillator
- TC1014-3.3VCT713CT-ND Microchip 3.3V Regulator
- MMBTH10-FDICT-ND (.28€) of KST10MTFCT-ND (0.18€) -> First one has a much larger stock. Is there something I am missing about the cheaper model?
- some caps and inductors for filtering 5V
- some resistors
Documentation
Notes
- The caps I bought
- For the anti-aliasing filters I use the redesign (with 0.15uH inductors instead of 0.22uH, as the latter are not in stock at digi-key)
Components
Missing
Bottom side
- R160a - R166a: I used 270k instead of 220k
- C115-117,126,127: 10uF 16V X5R 1210
- C180, C170: 27pF (filter redesign)
- R250: 3.3R 5% 0805 - I have 1.8R, 3.9R -> Use 3.9
- 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?)... According to Jacques, most small (pF) caps are NPO
- 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.
- Build notes talk about using silver solder, this is not really necessary I presume.
