LED power output indicator

[M0YDH]

Hello all
Following CQ-TV 258 article by Dave G4FRE on these indicators, I purchased two PCB's from the shop.
I didn't find the build very easy because there's no designated place for C2 and C3 on the component side silk screen. The board layout doesn't look like the the colour picture of the PCB on page 14. A photo of an assembled circuit would have been tremendously helpful.
I finished it and will show what I did to cope with the above in a moment.

Indicator first test using HT

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This shows the lights illuminated by rectified RF from the indicator. I hope this means that I've built it correctly. I ran out of hands to alter VR1 under Tx conditions!

Here's the component side

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Note the long track off pin 3 location for the main IC.

Here's a close up [before I cleaned the flux - yuk]

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I've put 1nF capacitor across pins 2 and 3 [+ supply] in mid-air. I've used a piece of Molex connector sprue waste to make a new track off pin 2 at 45 degrees. The surface mount electrolytic then could be soldered between pins 2 and 3 of the IC per the circuit diagram. It's not pretty.
Is this what people intended? Has anyone skilled in electronics built one of these boards up and has a photo to share?
May we have a clear picture of the image on page 15. I can't tell in either the PDF or the printed magazine where the indicator wire is going to be close to the transverter output track as per Dave's writing.
What do you think please?

All the best

David M0YDH

[G4FRE]

Noel just sent me a BATC pcb to check out, which I have just built. C2 shown in the article is in the wrong position and it along with it's tracks were not included on their PCB.

I have edited the pcb overview in my software to show much clearer where the components are fitted and the correct component designations. C2, a chip component is mounted on the PCB. C3 a leaded electrolytic is mounted on top of C2

I will take pictures at the weekend

A lead is connected from the c4 d1 junction on the power detector to the input pin on the LED meter PCB. The ground return is via the metal chassis

Hope that helps
Dave
g4fre

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[M0YDH]

Yes Dave thank you. I look forward to seeing your pictures.
73. David
May 2018 edit
Here's the pcb mod that I made on my second board

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I hope that helps anyone making indicators from first batch PCB's.

[M0YDH]

Hello
Here's the sensor and rectifier in action in my 70cm Mini-kits amplifier. They're fixed to the lid of the Mini-kits LPF case. The wire loop picks up stray RF well.

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Clearly it works well and the circuit schematic is correct.

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I adjusted the pot to leave a spare unlit bar at full power.

Thank you everyone. I hope the PCB's in the club shop get revised in line with Dave's design at the next batch.

Cheers
David M0YDH

[2W0ODS]

Made mine this weekend, pictures attached.
I ordered a bar LED with 7 Green and 3 Red, thinking the 3 Reds would come on at high power, I didn't check the circuit before I ordered the LED so didn't realise it was a common +Vdc for the LED array.

However I don't actually mind it in reverse as if only RED light up it means my power is down and something is wrong, so worked out better in the end.
Will build the RF circuitry tomorrow on a bit of VERO board.

[g0mjw]

Put it on the other side of the board perhaps?

[2W0ODS]

Put it on the other side of the board perhaps?

Yeah I did think of that, but I don't actually mind it starting at red as it indicates my transmitter isn't working properly.
And I'd have to move the pot over too as it protrudes higher than the LED. Food for thought if I do change my mind.

One thing that has me puzzled is the initial picture from the OP (M0YDH) his first LED segment isn't illuminated rather than the last segment... For some reason he's put Pin 11 of the LED and Pin one of the LM3914 to Ground?

[2W0ODS]

I changed my mind

Just de-soldered the LED Array and pot, flipped them over to the other side of the board, now it goes green to red... Obviously you have to mount the board upside down but that doesn't matter. The other thing is now when it's mounted the silkscreen of the connections are viewable.

Thought I'd post this in case anyone else decides to use a LED Array with multiple colours.

Pictures attached:

[M0YDH]

I think the PCB's are no longer in the shop. I found it easier to build G4FRE's design on stripboard than the muddle I got into with the PCB.
If it helps another builder, pictured is today's indicator board. LED 1 is between pins 10 and 11 and it lights up left to right in the picture. I used a component tester to find the anode and cathode of the LED unit then labelled them. The 10K potentiometer is on the track side. Its pins are visible by the electrolytic capacitor.

73
David M0YDH