Ultralight SWR indicator? (Part 1)

Well done Martin @DK3IT and Ondra @OK1CDJ.

I bought 4 and very happy with testing so far.

73 de Pedro, CT1DBS/CU3HF

Hi Martin

I ordered the kit from Hamshop for about three weeks. It is the perfect accessory for the Monutain Topper MTR3!

Many thanks to Martin and Hamshop!!!

vy 73 de Matt HB9FVF

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Can you please post the link?

Hi Barry
is already above but:

vy 73 de Matt HB9FVF

Thanks Matt!

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Actually that link also comes up in Czech until you click on the Union Jack flag :uk: at the top right of the screen.

73 Ed.

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Mounted a tinySWR in my MTR3 the same way…

I couple this with an EFHW tuner built into a dental floss case. Also visible are the two posts which serve as the paddle of a built-in touch keyer. I log using a small card clipped to the back of the radio. In this way sitting down (usually not a good idea) isn’t necessary. A tethered spacepen (stores in an attached soda straw) serves as writing instrument.

  • Fred KT5X (aka WS0TA)
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Martin,

The Mouser list has 3 components that are out of stock with long lead times. Could you have a look at that list and suggest replacement components if possible. I have the boards, just need the components.

HNY and 73,

Mike AD5A

NanoVNA is a good option once you run through the menu a couple times. It takes 1-2 minutes to change bands and check SWR. It will also show instant feedback to changes made to antenna.

I’ve learned with my Mountain-Toppers/TrailFriendly End-Fed Half-wave if the setup is generally the same (sloper far end 20’ above ground) SWR is pretty consistent. When checking SWR If 40m is good - 20m will be good also.

Erik
KE8OKM

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Hi,
can you please specify the components with availability issues?
Thanks!
73 de Martin, DK3IT

Hi Barry. Here is a photo of the tinySWR built into an MTR5B, upper left. Also built it into my MTR3. - Fred KT5X / WS0TA

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Here is the Mouser project list link, https://www.mouser.com/ProjectManager/ProjectDetail.aspx?AccessID=7968437adc

The components out of stock are:

Resistor - SMD 820 OHM 1/8 watt
Zener Diode 3.3V 600 ohm
Metal Oxide Resistor 100 ohms

73 and HNY,

Mike AD5A

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Hello, colleagues =)

I want to build TinySWR indicator on prototype board. I have FT23-43 cores, but them looks very small and hard to wind in my case.
Also I have FT-50-43. It seems like I am able just replace small core with bigger one without changing number of turns.

Is this assumption correct?

br,
Yury

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Yes, 73 Chris

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There is another option

73 Armin

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Hello :wave: again DR OP :smiley:

I am building TinySWR by my own (without kit).
I gathered almost all parts except D1 and D2.

It would be great if you suggest DIP mount alternatives or SMD for D1 and D2 because I am not able to find these parts.

Thank you in advance!

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If you want to build the indicator with non-SMD components, you can always use the original design by Hans Steinort (DF3OS) from

http://sem.pl/sp5jnw/konstrukcje/atudf3oshtm/atudf3oseng.pdf

The TinySWR circuit is based on that design, with improvements from Dieter Engels (DJ6TE) and Hannes Hiller (DL9SCO).

I only changed the values of certain components, modified the LED array, and designed a SMD PCB so that it is easier to assemble.

Hope that helps.

73 de Martin, DK3IT

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Thank you, Martin

This helped a lot.

Now it is clear for me that it’s a regular zener diode with voltage 3.3V.
In original version it was 2.7V (2V7).

Sorry for stupid question.

I think I start with original version with two led SWR indicators.

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The last question,
Probably someone has better knowledge =)

Why line voltage indicator was moved from “hot” line to secondery winding of current transformer?

I have compiled a list of the parts at Reichelt:

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