If you can add an RF detector probe to your test equipment inventory it might be

very useful for measuring RF levels at various points in the transceiver.?

OK. ?So a few more facts for the puzzle.?

OK. ?So a few more facts for the puzzle.

-One of the extra capacitors is 100 pF in parallel with L7. ?As per Wayne NB6M as written up in BitX Hacks Blog.

-I tried to measure mA again, and something is really odd. First, I am running power from a battery box, 12.85v. ?
All connections are Powerpoles. ?I checked the power at the power distribution block (inside the radio, behind the fuse) 12.90v. ?My multimeter is a Mastech MS8264. ?Black lead is plugged into "COM", red lead into "mA". ?The dial is set to 10 A ?DC. ?The value that I see is -1.10 A, rising slowly to -0.45 A. ?Yes, I said negative values, ?No, I don't have my wires crossed. ?What the heck!

Jerry,
Thanks for all of the good leads. ?It will take me bit to figure out some of them. ?A few I can respond to now.

"If all you are doing is pressing the PTT button, you won't see any RF going out.
On a single sideband rig, you only get RF to the antenna wen there is audio into the microphone."
? ? ? Yep, I have tried "hallooooing" into the mic - not apparent effect.

"Put tape over the ends of all the extra leads coming out of that Raduino"
? ? ?My leads are pretty tidy. ?Not promising that I did't already short something, but I usually keep things pretty tidy.

"Make sure your antenna connector is wired up properly.
Don't laugh, it happens."
? ? ?Well, I have replaced the separate leads as supplied by HFSigs, with a short piece of tiny coax to a BNC. ?I am using the supplied connector. ?How do I confirm that POS and GRND are connected to the proper side of the connector (board)?

It will take me a bit to figure out the rest of your feedback. ?Thank you very much!?

-I have a QRP dummy load (), and the voltage measured (between ground and VRMS pin is something like 0.57) (RF power = (0.57^2)/50= .0065 watts) when the mic is keyed.

Well, I sure am grateful for people with great test equipment!!!!

Sent from my iPhone

On Oct 24, 2017, at 6:46 PM, Vince Vielhaber <vev@...> wrote:


You either don't recall or you didn't read it. Yesterday afternoon I re-measured using a Tek 11402 scope and corrected my previous comment.

Vince.

On 10/24/2017 04:42 PM, Jerry Gaffke via Groups.Io wrote:
As I recall, you showed some alarmingly low signal levels as the
frequency went up.
If the si5351 can only give 8ma at dc, your notes suggest it gets
awfully small at 45mhz+SignalFreq
into the first mixer on the ubitx.

Though Gordon's right, there is some conduction through a schottky diode
even at 200mv or less.
Perhaps somehow the ubitx works well enough, but could do better if the
diode ring mixers were driven harder.

Jerry

On Tue, Oct 24, 2017 at 01:03 pm, Vince Vielhaber wrote:

I posted the RMS values of all four output modes yesterday. Do you
also want the P-P values?

--
Michigan VHF Corp.

You either don't recall or you didn't read it. Yesterday afternoon I
re-measured using a Tek 11402 scope and corrected my previous comment.

Vince.


On 10/24/2017 04:42 PM, Jerry Gaffke via Groups.Io wrote:

As I recall, you showed some alarmingly low signal levels as the
frequency went up.
If the si5351 can only give 8ma at dc, your notes suggest it gets
awfully small at 45mhz+SignalFreq
into the first mixer on the ubitx.

Though Gordon's right, there is some conduction through a schottky diode
even at 200mv or less.
Perhaps somehow the ubitx works well enough, but could do better if the
diode ring mixers were driven harder.

Jerry

On Tue, Oct 24, 2017 at 01:03 pm, Vince Vielhaber wrote:

I posted the RMS values of all four output modes yesterday. Do you
also want the P-P values?

On Oct 24, 2017, at 6:46 PM, Vince Vielhaber <vev@...> wrote:


You either don't recall or you didn't read it. Yesterday afternoon I re-measured using a Tek 11402 scope and corrected my previous comment.

Vince.

On 10/24/2017 04:42 PM, Jerry Gaffke via Groups.Io wrote:
As I recall, you showed some alarmingly low signal levels as the
frequency went up.
If the si5351 can only give 8ma at dc, your notes suggest it gets
awfully small at 45mhz+SignalFreq
into the first mixer on the ubitx.

Though Gordon's right, there is some conduction through a schottky diode
even at 200mv or less.
Perhaps somehow the ubitx works well enough, but could do better if the
diode ring mixers were driven harder.

Jerry

On Tue, Oct 24, 2017 at 01:03 pm, Vince Vielhaber wrote:

I posted the RMS values of all four output modes yesterday. Do you
also want the P-P values?

--
Michigan VHF Corp.

As I recall, you showed some alarmingly low signal levels as the
frequency went up.
If the si5351 can only give 8ma at dc, your notes suggest it gets
awfully small at 45mhz+SignalFreq
into the first mixer on the ubitx.

Though Gordon's right, there is some conduction through a schottky diode
even at 200mv or less.
Perhaps somehow the ubitx works well enough, but could do better if the
diode ring mixers were driven harder.

Jerry

On Tue, Oct 24, 2017 at 01:03 pm, Vince Vielhaber wrote:

I posted the RMS values of all four output modes yesterday. Do you
also want the P-P values?

There are many things that I don't know, and I sincerely thank all of you for the resource that is growing here in this group.

I am looking for some assistance troubleshooting a Bitx40.
Go easy on me, I have very little idea of what I am doing.

Let me tell you what I do know...
-This is my first HF radio, and my first kit build radio - what could possibly go wrong, right?
-I am running this radio from a 12v Battery. (12.4v -13.2v ish)
-100' of coax to an inverted V that has been tuned to the middle of the band.
-Receive works well.? I can regularly hear folks from the western half of North America, and frequently the east coast as well as others speaking Spanish (Mexico?? South America?)
-Transmit appears to not work.? I have not made any successful QSO's.
-I have a QRP dummy load (), and the voltage measured (between ground and VRMS pin is something like 0.57) (RF power = (0.57^2)/50= .0065 watts) when the mic is keyed.
-I have tested the voltages of all of the transistors and while not exactly the same, they are very close to the values published by?Randy, K7AGE
-I never saw the "Magic smoke"
-There are very few mods to this BitX40.? Allard's code, extra heat-sink one the raduino, and larger heat-sink on the board, extra capacitor on tuning pot, (there is one other capacitor that I added, but at the moment, I cannot precisely describe where I put it), external speaker/mic by BTech
-I don't have access to test equipment beyond a multi meter, small dummy load, and an antenna analyser.
-I have tried to measure Amps drawn, but I was likely doing something incorrectly as the values were not even close tho what is described in the BitX40 write up.
-Nothing gets hot when powered on, no visually obvious defects.
-I have listened (via WebSDR) to a frequency that I was transmitting on, and received nothing.? I'm not sure if I was too far away, or if I was really not transmitting.? I live far away from most everything so popping over to the next ham meeting is non-trivial.


So what can I test?? Are there any other troubleshooting guides out there?
Thanks for any ideas or suggestions that you might have.

WA7NJB

I'm going to have a look at the 2430A.

Current setup:
Tek 11402 Scope w/ 11A32 400MHz plugin
Tek P6121 10x probe - 1 meg termination in the scope
No bandwidth limiting

Adafruit si5351 board CLK2 terminated into 51 ohms.
Standalone Nano controlling it.
NOTE: CLK2 is also used for the following measurements.

There is a difference in output between 7.5MHz and 35.5MHz, but only about 15mv rms.

There's a bit of ringing on the square wave but that's probably in my setup.

Ok, with the above setup, at 11.020 MHz:

2ma setting: 190 mv rms.
4ma setting: 380 mv rms.
6ma setting: 560 mv rms.
8ma setting: 735 mv rms.

I posted the RMS values of all four output modes yesterday. Do you also want the P-P values?