Difference between pages "User:SadlerWestcott517" and "RF Attenuators"

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32 Easy SEARCH ENGINE OPTIMISATION Ideas For Small Businesses Econsultancy
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== Homebrew RF Attenuators ==
  
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SEARCH ENGINE OPTIMIZATION (Search Engine Optimization) is the method of creating a web site extra visible in search outcomes, additionally termed enhancing search rankings. This was made easier with the arrival of expertise and Google has change into the go-to go looking engine for Billions of individuals all all over the world. After getting the appropriate individuals clicking by way of from these search engine outcomes pages (SERPs), extra visitors is best. By creating content around the in style keywords that your audience is utilizing to find info online, you might be already giving great worth to your web site visitors.
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[[file:Atten_30dB_20dV_P1812-720px.jpg]]
  
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Moreover the rating components change through time. Search engines like google love great content and consumers want quality content to raised understand the value your group can provide. Here's how it works: Google (or any search engine you're using) has a crawler that goes out and gathers information about all the content material they'll find on the Web.
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== Attenuators ==
  
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When strategically placing your WEB OPTIMIZATION key phrases and phrases in your pages, it is vital to avoid over-optimization. Nevertheless, search engine algorithms continue to vary with time because the Internet evolves, so on-line retailers have to evolve with the engines. Image Title and ALT Tags - If you are using images in your web site or inside your weblog content material, you will also want to embrace your key phrase or phrase within the picture name and alt tag.
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[[file:Chart_mW_vs_dbM.PNG]]
  
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However, we do have a pretty good understanding of a number of the components that impact search engine results page (SERP) rankings. With a bit SEARCH ENGINE OPTIMIZATION information underneath your belt, you can be on your approach to enhancing your brand's search engine rating in no time. Think about how what you are promoting would profit in the event you might analyze search trends on Google , find search phrases that are associated to your enterprise domain and customise content material in your website to serve the precise wants of your prospects.
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=== 30 dB Attenuator ===
  
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If you need your web site to get traffic from Google or other serps, it's good to be sure that it contains content material created round the correct key phrases. Our paid subscriptions - Key phrase Instrument Professional and Key phrase Instrument API totally help all Google domains and languages and supply very correct search volume, value-per-click and Google Advertisements Competitors Data for key phrases in all 192 supported nations, 47,035 particular person places and forty six languages.
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* [http://leleivre.com/rf_pipad.html Pi Attenuator Calculator]
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[[file:Atten30dB_P116-720px.jpg]]
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[[file:30dB_Attenuator.PNG]]
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 +
* Built
 +
** Standard 5% resistor values
 +
** R1 = 820 in parallel with 22K = 790.6 ohms
 +
** R2 = 2 paralleled 120 Ohm 1/4W resistors paralleled with 470 ohms = 53.2 ohms
 +
** Flat from 0-30 MHz
 +
** Measured attenuation is flat
 +
*** -30.01dB at 1 MHz
 +
*** -30.24dB at 30 MHz
 +
** Input Impedance - 53.1 ohms, 21.3nF
 +
** SWR 1.06
 +
** 1/2W max (5VDC max, 0 ohm source)
 +
 
 +
* NanoVNA scan data
 +
 
 +
[[file:30dB_Attenuator_NanoVNA_Setup_Curve_900MHz.PNG]]
 +
 
 +
[[file:30dB_Attenuator_NanoVNA_Data_900MHz.PNG]]
 +
 
 +
* LTSPICE Simulation
 +
 
 +
[[file:LTSPice_30dB.PNG]]
 +
 
 +
=== 20 dB Attenuator ===
 +
 
 +
[[file:Atten_20dB_P115-720px.jpg]]
 +
 
 +
[[file:20dB_Attenuator.PNG]]
 +
 
 +
* Build
 +
** Standard 5% resistor values
 +
** R1 = 2 of 510 in parallel also in parallel with 8.2K = 247.3 ohms
 +
** R2 = 2 paralleled 150 Ohm 1/2W resistors paralleled with 330 ohms = 61.11 ohms
 +
** Flat from 0-30 MHz
 +
** Measured attenuation is flat
 +
** Input Impedance - tbd ohms, tbd nF
 +
** SWR tbd
 +
** 1W max (8.6 V max, 0 ohm source)
 +
 
 +
[[file:20dB_Attenuator_NanoVNA_Setup_Curve_900MHz.PNG]]
 +
 
 +
[[file:20dB_Attenuator_NanoVNA_Data_900MHz.PNG]]
 +
 
 +
* LTSPICE Simulation
 +
 
 +
[[file:LTSPice_20dB.PNG]]
 +
 
 +
=== 10 dB Attenuator ===
 +
 
 +
[[file:Atten_10dB_P115-720px.jpg]]
 +
 
 +
[[file:10dB_Attenuator.PNG]]
 +
 
 +
* Build
 +
** Standard 5% resistor values
 +
** R1 = 2 of 150 in parallel also in parallel with 1.5K = 71.43 ohms (0.3% error)
 +
** R2 = 3 of 330 Ohm 1/4W parallel resistors paralleled with 810 ohms = 96.85 ohms (0.62% error)
 +
** Flat from 0-30 MHz
 +
** Measured attenuation is flat
 +
** Input Impedance - tbd ohms, tbd nF
 +
** SWR tbd
 +
** 3/4W max (9.1 V max, 0 ohm source)
 +
 
 +
[[file:10dB_Attenuator_NanoVNA_Setup_Curve_900MHz.PNG]]
 +
 
 +
[[file:10dB_Attenuator_NanoVNA_Data_900MHz.PNG]]
 +
 
 +
* LTSPICE Simulation
 +
 
 +
[[file:LTSPice_10dB.PNG]]
 +
 
 +
=== Attenuator Construction ===
 +
 
 +
* Single side copper clad PCB
 +
** Approx 2"x1"
 +
* Clean with steel wool
 +
* Solder SMA connectors
 +
** Use large alligator clips to hold while soldering
 +
** Solder on sides only
 +
 
 +
[[file:Atten_01_SMAs_720px.jpg]]
 +
 
 +
* Cut "T" Shaped pads
 +
** I used nibbler
 +
* Center fits between connector ground pins
 +
* Glue down pads with Superglue
 +
 
 +
[[file:Atten_02_Pads_720px.jpg]]
 +
 
 +
* Solder center pin with big solder blob
 +
** A bit too high for direct contact
 +
* Verify raised pad does not short to ground
 +
 
 +
[[file:Atten_03_Solder CenterPads_720px.jpg]]
 +
 
 +
* Solder side resistor(s)
 +
* Leave room for center resistor(s)
 +
 
 +
[[file:Atten_04_Solder Side_Resistors_720px.jpg]]
 +
 
 +
* Measure side resistors from pad to ground
 +
* Should match value
 +
* Solder center resistor(s)
 +
 
 +
[[file:Atten_05_Solder Center_Resistors_720px.jpg]]
 +
 
 +
* Verify no shorts between centers and ground
 +
 
 +
== References ==
 +
 
 +
<video type="youtube">A5gGeV7CiQ0</video>

Revision as of 11:50, 7 September 2021

Homebrew RF Attenuators

Atten 30dB 20dV P1812-720px.jpg

Attenuators

Chart mW vs dbM.PNG

30 dB Attenuator

Atten30dB P116-720px.jpg

30dB Attenuator.PNG

  • Built
    • Standard 5% resistor values
    • R1 = 820 in parallel with 22K = 790.6 ohms
    • R2 = 2 paralleled 120 Ohm 1/4W resistors paralleled with 470 ohms = 53.2 ohms
    • Flat from 0-30 MHz
    • Measured attenuation is flat
      • -30.01dB at 1 MHz
      • -30.24dB at 30 MHz
    • Input Impedance - 53.1 ohms, 21.3nF
    • SWR 1.06
    • 1/2W max (5VDC max, 0 ohm source)
  • NanoVNA scan data

30dB Attenuator NanoVNA Setup Curve 900MHz.PNG

30dB Attenuator NanoVNA Data 900MHz.PNG

  • LTSPICE Simulation

LTSPice 30dB.PNG

20 dB Attenuator

Atten 20dB P115-720px.jpg

20dB Attenuator.PNG

  • Build
    • Standard 5% resistor values
    • R1 = 2 of 510 in parallel also in parallel with 8.2K = 247.3 ohms
    • R2 = 2 paralleled 150 Ohm 1/2W resistors paralleled with 330 ohms = 61.11 ohms
    • Flat from 0-30 MHz
    • Measured attenuation is flat
    • Input Impedance - tbd ohms, tbd nF
    • SWR tbd
    • 1W max (8.6 V max, 0 ohm source)

20dB Attenuator NanoVNA Setup Curve 900MHz.PNG

20dB Attenuator NanoVNA Data 900MHz.PNG

  • LTSPICE Simulation

LTSPice 20dB.PNG

10 dB Attenuator

File:Atten 10dB P115-720px.jpg

10dB Attenuator.PNG

  • Build
    • Standard 5% resistor values
    • R1 = 2 of 150 in parallel also in parallel with 1.5K = 71.43 ohms (0.3% error)
    • R2 = 3 of 330 Ohm 1/4W parallel resistors paralleled with 810 ohms = 96.85 ohms (0.62% error)
    • Flat from 0-30 MHz
    • Measured attenuation is flat
    • Input Impedance - tbd ohms, tbd nF
    • SWR tbd
    • 3/4W max (9.1 V max, 0 ohm source)

File:10dB Attenuator NanoVNA Setup Curve 900MHz.PNG

File:10dB Attenuator NanoVNA Data 900MHz.PNG

  • LTSPICE Simulation

LTSPice 10dB.PNG

Attenuator Construction

  • Single side copper clad PCB
    • Approx 2"x1"
  • Clean with steel wool
  • Solder SMA connectors
    • Use large alligator clips to hold while soldering
    • Solder on sides only

Atten 01 SMAs 720px.jpg

  • Cut "T" Shaped pads
    • I used nibbler
  • Center fits between connector ground pins
  • Glue down pads with Superglue

Atten 02 Pads 720px.jpg

  • Solder center pin with big solder blob
    • A bit too high for direct contact
  • Verify raised pad does not short to ground

Atten 03 Solder CenterPads 720px.jpg

  • Solder side resistor(s)
  • Leave room for center resistor(s)

Atten 04 Solder Side Resistors 720px.jpg

  • Measure side resistors from pad to ground
  • Should match value
  • Solder center resistor(s)

Atten 05 Solder Center Resistors 720px.jpg

  • Verify no shorts between centers and ground

References

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