Thank you Adam by the suggestion, this is the way I meassure the power output of my WSPR/FT8 beacon (Vpp*0,35)^2/RL in this case ((17V*0,35)^2)/50 would yield 700 mW approx. The initial testing has been very much satisfactory, in reception as reported in pskreporter.info the greatest distance reported so far is some well over 19K Km (JA), on TX I was able to work a couple of PY stations (some 2000 Km away) when the band wasn't quite opened yet; what else can a small device like this be asked (attached is the pskreporter.info logbook over the past day or so, reports to my station is of the permanent beacon I have, not the D4D). I'd shared in some of the experiences in building the kit, the blog is in Spanish but Google translate will yield a half decent translation give or take a couple of words. Thank you for the very good support while building the kit. 73 de Pedro, LU7DID  ?
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Colla,
The diode mod suggested by KD1JV can increase RF output about 1 dB. 在 2019年10月16日，上午5:30，Dr. Pedro E. Colla (LU7DID) < lu7did@...> 写道：
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I had only applied the input level mod but I decided later it wasn’t wise to start adding mods to a circuit I am not familiar with and then completed the building as vanilla as possible. 73 Pedro LU7DID Did you add the optional modification diode to suppress spurious transmissions? If so, this will likely account for the output power drop.
Conor
On Tue, 15 Oct 2019, 22:07 Dr. Pedro E. Colla (LU7DID), < lu7did@...> wrote: Although the power meter shows about 200-300 mW output the current is 22 mA on RX and 290 mA on TX, at 12Vcc this is 3.5W of power input, not sure what is the expected yield of the PA but even taking as low as 50% it should be a good over 1.5W of output. SWR is 1:1.2. The current is aligned with other posts I saw and being regarded as normal for 20 mts. So I can not square the meassured output power with this.
I'm doing some FB contacts at the regional level on 20 mts which isn't bad, this is not a surprise, my beacon is using 100 mW and still being reported all over the world, FT8 is an amazing mode.
73 de Pedro, LU7DID
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Colla,
Glad that you can make QSO with D4D now. The efficiency of the TX driver and final is low because they are biased in type A or A/B. The power measurement is a bit tricky due to the DSB spectrum. Based on 290mA, I suppose you will get more than 0.5 watt. You can verify using an oscilloscope. The peak to peak RF voltage should be somewhere at 17V, I suppose. 在 2019年10月16日，上午5:07，Dr. Pedro E. Colla (LU7DID) < lu7did@...> 写道：
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Show quoted text
Although the power meter shows about 200-300 mW output the current is 22 mA on RX and 290 mA on TX, at 12Vcc this is 3.5W of power input, not sure what is the expected yield of the PA but even taking as low as 50% it should be a good over 1.5W of output. SWR is 1:1.2. The current is aligned with other posts I saw and being regarded as normal for 20 mts. So I can not square the meassured output power with this.
I'm doing some FB contacts at the regional level on 20 mts which isn't bad, this is not a surprise, my beacon is using 100 mW and still being reported all over the world, FT8 is an amazing mode.
73 de Pedro, LU7DID
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I had only applied the input level mod but I decided later it wasn’t wise to start adding mods to a circuit I am not familiar with and then completed the building as vanilla as possible. 73 Pedro LU7DID
Did you add the optional modification diode to suppress spurious transmissions? If so, this will likely account for the output power drop.
Conor
On Tue, 15 Oct 2019, 22:07 Dr. Pedro E. Colla (LU7DID), < lu7did@...> wrote: Although the power meter shows about 200-300 mW output the current is 22 mA on RX and 290 mA on TX, at 12Vcc this is 3.5W of power input, not sure what is the expected yield of the PA but even taking as low as 50% it should be a good over 1.5W of output. SWR is 1:1.2. The current is aligned with other posts I saw and being regarded as normal for 20 mts. So I can not square the meassured output power with this.
I'm doing some FB contacts at the regional level on 20 mts which isn't bad, this is not a surprise, my beacon is using 100 mW and still being reported all over the world, FT8 is an amazing mode.
73 de Pedro, LU7DID
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Did you add the optional modification diode to suppress spurious transmissions? If so, this will likely account for the output power drop.
Conor
On Tue, 15 Oct 2019, 22:07 Dr. Pedro E. Colla (LU7DID), < lu7did@...> wrote: Although the power meter shows about 200-300 mW output the current is 22 mA on RX and 290 mA on TX, at 12Vcc this is 3.5W of power input, not sure what is the expected yield of the PA but even taking as low as 50% it should be a good over 1.5W of output. SWR is 1:1.2. The current is aligned with other posts I saw and being regarded as normal for 20 mts. So I can not square the meassured output power with this.
I'm doing some FB contacts at the regional level on 20 mts which isn't bad, this is not a surprise, my beacon is using 100 mW and still being reported all over the world, FT8 is an amazing mode.
73 de Pedro, LU7DID
|
Although the power meter shows about 200-300 mW output the current is 22 mA on RX and 290 mA on TX, at 12Vcc this is 3.5W of power input, not sure what is the expected yield of the PA but even taking as low as 50% it should be a good over 1.5W of output. SWR is 1:1.2. The current is aligned with other posts I saw and being regarded as normal for 20 mts. So I can not square the meassured output power with this.
I'm doing some FB contacts at the regional level on 20 mts which isn't bad, this is not a surprise, my beacon is using 100 mW and still being reported all over the world, FT8 is an amazing mode.
73 de Pedro, LU7DID
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Hi Conor,
Thank you for the tip. The TX is working now. Although with very limited power. Hard to measure but in the order of 200 mW. SWR is Ok.
73 de Pedro, LU7DID
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Does the TX light go on? If it does, check the solder joints for the three coils. If there is enamel still on the ends of their wires, they may not form a proper connection.
I had this problem recently. I simply reheated the solder joints and waited until the enamel melted off and burned away. This solved the issue for me.
Conor
On Tue, 15 Oct 2019, 18:41 Dr. Pedro E. Colla (LU7DID), < lu7did@...> wrote: RX apparently fixed, C2/C3 were the corresponding to 40m therefore the oscillator didn't started.
Now going after the TX part which isn't working.
73 de Pedro, LU7DID
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RX apparently fixed, C2/C3 were the corresponding to 40m therefore the oscillator didn't started.
Now going after the TX part which isn't working.
73 de Pedro, LU7DID
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Hi Adam,
What would be your suggested mod to transform the D4D into a single band multipurpose transceiver by generating the frequency from an external DDS?
73 de Pedro, LU7DID
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Hi, Finished the build of the D4D kit without significant issues after a cold soldering prevented the VOX to work properly. Did some test during the build but not the receiver test. Upon finishing it doesn't seems to work neither RX nor TX. Focusing on RX first. Energy is Up, green led is lit. Audio is present at the audio out socket, a clear constant tone and a more subtle hish noise. Spectrogram is attached. No signals are decoded. My nearby transmitting beacon in 14 MHz is shown as multiple signals (probably because of overloading) but the reception is weak, no decoding can be made by WSJT-x. No other signals are decoded. Even if there are activity. D4D is working with my best antenna during the test. Before to start following the circuit step by step any general suggestion for troubleshoot based on common past issues (I look for them at the forum but found none). Thanks in advance!!! 73 de Pedro LU7DID 
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Re: Handedness of winding doesn't matter?
There is no right way. Either way is okay. 在 2019年10月15日，上午8:44，Bryan Brauer < bryan@...> 写道：
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Why not just rewind the right way? Bryan B. Brauer, PEConsulting Engineer
Hi,?
I just wound this with the opposite handedness of the example in the build instructions. I just wanted to be doubly sure that it doesn't matter, for this particular component. It's fine this way, right? I'm just concerned that there might be some subtle board layout consideration that makes it better to wind it the other way.
? ? ? 
Thanks, Adrian, KR0DAK
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Re: Handedness of winding doesn't matter?
Why not just rewind the right way? Bryan B. Brauer, PEConsulting Engineer
Hi,?
I just wound this with the opposite handedness of the example in the build instructions. I just wanted to be doubly sure that it doesn't matter, for this particular component. It's fine this way, right? I'm just concerned that there might be some subtle board layout consideration that makes it better to wind it the other way.
? ? ? 
Thanks, Adrian, KR0DAK
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Re: Handedness of winding doesn't matter?
Direction of winding does not matter.
-- Larry Lovell
73's N7RGW
Cell: 214-697-1729
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Re: Handedness of winding doesn't matter?
In your application it should make no difference.? It's when you
are winding a two or more winding transformer that it becomes a
problem as the wires won't come off the core in the proper
arrangement.? Electrically it makes no difference.? In other words
the physical layout for the board holes is what matters.?
Electrically there would be no difference.
Lee, w0vt
On 10/14/2019 3:05 PM, Adrian Boyko
wrote:
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Show quoted text
Hi,?
I just wound this with the opposite handedness of the
example in the build instructions. I just wanted to be doubly
sure that it doesn't matter, for this particular component.
It's fine this way, right? I'm just concerned that there might
be some subtle board layout consideration that makes it better
to wind it the other way.
? ? ? 
Thanks,
Adrian, KR0DAK
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Handedness of winding doesn't matter?
Hi,?
I just wound this with the opposite handedness of the example in the build instructions. I just wanted to be doubly sure that it doesn't matter, for this particular component. It's fine this way, right? I'm just concerned that there might be some subtle board layout consideration that makes it better to wind it the other way.
? ? ? 
Thanks, Adrian, KR0DAK
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Hi Adam,
Thank you for your quick response. It turned out to be a cold soldering point on R16 GND side.
73 Pedro, LU7DID
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Hello,
This email message is a notification to let you know that the following files have been updated in the Files area of the [email protected]
group.
Uploaded By:
Adam Rong <rongxh@...>
Description:
In this version, we have updated the modifications to include the latest information.
Cheers,
The Groups.io Team
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Colla,
Sorry for replying late. Check if you have swapped Q5 and Q6. 2N3906 and 3904 are very similar looking. 在 2019年10月14日，上午7:48，Dr. Pedro E. Colla (LU7DID) < lu7did@...> 写道：
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Hi,
Building the D4D at Step 2 WITH the MOD on pag 25 implemented when testing the step upon powering the circuit the relay clicks but the amber LED goes and stays on.
On previous STEP 1 testing the green LED went ON correctly.
Any hint?
73 de Pedro, LU7DID
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Hi,
Building the D4D at Step 2 WITH the MOD on pag 25 implemented when testing the step upon powering the circuit the relay clicks but the amber LED goes and stays on.
On previous STEP 1 testing the green LED went ON correctly.
Any hint?
73 de Pedro, LU7DID
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Dr. Pedro E. Colla (LU7DZ)
Larry Lovell