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I ordered Dec 23. Arrived Feb 22 in USA. Paypal had DHL tracking entered on Feb 19.听 I never received notice of it being shipped. Also, there were no duties or taxes.

--
Jason Schlager
KM6AUS

The uBitx surface mount R's and C's are all in the 1206 package.
The surface mount 2n3904's are are mmbt3904's.
The audio amp is the TDA2822M variant (M says it's in the 8 pin DIP package).

So "didn't have power on SSB" means you didn't see power into a wattmeter (with dummy load) when attempting to transmit?
Have you tried transmitting CW with a hand key?
Is that scope good to 10mhz or so?

Inspect the entire board carefully under good light and with magnification for damage somewhere in shipping.
Often the torroids have trouble with broken or shorted wires, or enamel left on the wire, or an otherwise
poor solder job.听 However, if the receiver worked, all torroids except those between Q90 and the IRF510's
are probably ok, and the mixers and local oscillators are fine.
The TX side of the BiDi amps is probably ok since they are simple and auto-stuffed and seldom have trouble.

Switch to one of the low bands like 80m or 40m, hopefully within range of the scope
Remove power (PA-PWR) from the IRF510's so you don't have to worry about dummy loads and such
while debugging the transmitter, when things are working you should see a couple volts of RF at the
gates of the IRF510's.

When pressing PTT with no input to the microphone, all those 2n3904's at Q90,911,912,92,93,96,97听
should have around 0.6 volts dc between base and emitter, and the emitter should be a little bit above ground.听
You can check this with a DVM.听 Do they all look ok?

When speaking into the mike or using the hand key, I believe the base of Q90 will have something on the
order of 50mv rms of RF on it at the operating frequency, can you see that with the scope?

If Q90 is getting RF, then听follow that on through the other stages, should see a volt or two rms
of RF at the gates of the IRF510's.听 The gates of the IRF510's should be biased by RV2 and RV3 to
around 3 or 4 volts (but DON'T twiddle RV2 and RV3 unless monitoring quiescent drain current at PA-PWR).听

If you do see RF at the IRF510 gates, then it's time to attach a dummy load and restore PA-PWR,
see if the dummy load gets signifcant power when attempting to transmit.
If not, do the drains of the IRF510's get 12v dc when ptt is pressed?
Does PA-PWR current go up to 200ma or so (100ma of quiescent drain current per IRF510) when pressing ptt
with no audio into the mike, demonstrating that the IRF510's are probably working fine?

Jerry, KE7ER

Should we add Carl's case to the ubitx.net enclosures section.

I purchased one of these, by the way, and the quality is excellent!!

--Neil, W2NDG

Hello Walter,

I have been doing some work around this same subject. You can take the low-level audio signal to an external amplifier by connecting the signal in to Vol-H (R170). This is the yellow wire coming off of the audio connector (diagram on HF Signals is incorrect). You can also reduce the headphone volume by inserting two small value resistors (under 100 ohm) in series with the output of the audio amp. Do this by connecting the output of the amp to pins 4&5 of the headphone jack. Now put the resistors across pins 1&2. I hope that makes sense! Google the Realistic DX-160 schematic to see what I鈥檓 talking about.

My name is Qonita, and I am a student i my last semester. I'd like to learn about BITX40 because it is very suitable for my last project.听

I design a case for my uBITX. see the attached PDF File.听 I print them on my 3D Printer and have had very good feedback from the ones I have sold.听 Take a look.

On Wed, Feb 28, 2018 at 05:33 am, Kerr Smith wrote:

Hi Walter,

There is a clear schematic at the following location (found on the hfsignals site):



This is for version 3 of the UBITX.

As for getting a selection of SMD resistors I would suggest getting a mixed pack from somewhere like Banggood:



I have bought several of these small kits in the past and they are a great way to instantly (after shipping of course) get a wide range of resistor values.

I hope this helps,

Kerr

Outstanding Schematic and SMD source.听 What value SMD's do you think these are? I see 0603,0805, 1206.听 What is the standard size using for electronic projects like these?

Thanks for your help
听
--
73, W9KJO
Walter

On Wed, Feb 28, 2018 at 05:15 am, Thomas Smith wrote:

Hi Walter,

What are you using to power your UBITX?听 If you are using a power supply plugged into your wall, this may be coupling 60 (50?) Hz noise into your rig.听 If you are powering it from the wall, can you use a battery (even just temporarily) to see if that is the source?

Tom

On Wed, Feb 28, 2018 at 1:23 PM, Walter <W9KJO@...> wrote:

I notice while using headphones with my new UBITX that there is a low level hum in my headphones.听 I only seem to notice this with the headphones at low volume.

Is there a fix for this?

Thanks

--
73, W9KJO
Walter

听

听

It is powered off the batteries from my solar system, 12vdc system used only for my ham radio station, no inverter (yet).听 Four large deep cycle batteries charged by an MPPT Controller.听 I check it for noise often.听 I have a power supply on the batteries to make up for low charge at night but it was off at the time as that charger is disconnected by my Internet relays during the daytime.听 I'm pretty sure there wasn't any noise introduced from my power supply,BTW

BTW, I am so impressed by the Solar System, now 2 years old, That I am going to build a second system to power much of my house in the near future.听 These panels even provide charge under cloud cover, it drops from 15 amps to 3 or 4 amps but that is enough to keep the batteries at charge even when operating my station at 27 amp current draw with the batteries making up the difference.听 The duty cycle is low enough, even while in digitial modes, that it keeps up on only a few amps.听 I even use my 12vdc HF Amp while on solar power.听 It's been amazing and reliable.

I do have a DC Boost Regulator installed in my UBITX to raise the PA Voltage to a stable 24vdc.听 I thought this might be the noise so I disconnected it and used only the 13.8vdc from my batteries but the noise was still present.听 So the boost regular it not causing the noise.

--
73, W9KJO
Walter

Hi Walter,

There is a clear schematic at the following location (found on the hfsignals site):



This is for version 3 of the UBITX.

As for getting a selection of SMD resistors I would suggest getting a mixed pack from somewhere like Banggood:



I have bought several of these small kits in the past and they are a great way to instantly (after shipping of course) get a wide range of resistor values.

I hope this helps,

Kerr

I totally agree with you Michael.听 I think some realized it after they got things together.听 I've seen them put the large 4 or 8 pin mic jacks next to the tuning knob.听 That would drive me nuts.听听 Yours looks clean and smooth.听听 Ne mess cables in the front.听 Even the side would be a better option than the front in my opinion.听

73, Michael
KM4OLT

I ordered mine on the 29th of December 2017, and I haven't gotten notice of shipping yet.
Dan W2DLC

Carl,

Bad connection on the power jack, see if you can find another jack from a discarded walwart the fits snugly.
Some have a slightly small hole and can be drilled to enlarge to fit.

Raj

Well, I just got a paypal notice that the tracking of my uBitx as been issued. I ordered my uBitx on Jan 2 and today is Feb 28. So soon I'll have the uBitx in hand, not sure when I'll get a chance to build it up but hopefully it will be soon.

-Obe (KC4VZT)
Middleburg, FL

Have you already aligned the PA BIAS and PA DRIVE according to the instructions on hfsignals.com?

1. Attach a dummy load to the antenna
2. Insert a ammeter (you may use your VOM meter in high amps range) into the PA power supply鈥檚 positive line
3. Keep the PA BIAS preset (RV1) to fully clockwise position. Now when you press the PTT button, the ammeter should read about zero.
4. Increase PA BIAS without speaking into the mic until the PA current shows 100 ma
5. Give a loud and long HAAAALLLOOWW into the mic and the current should jump to slightly over 1 amp
6. Adjust the RV136 to increase the PA drive if the current doesn鈥檛 jump all the way to 1A
7. Keep monitoring your signal on a nearby receiver.

73 Allard PE1NWL

I notice while using headphones with my new UBITX that there is a low level hum in my headphones.听 I only seem to notice this with the headphones at low volume.

Is there a fix for this?

Thanks

--
73, W9KJO
Walter

If I use the Speaker jack with headphones, then I naturally have to turn the audio down very low.听 However, if doing digital modes then the audio is too low for the signal link.听

What would I need to do to install a second jack for headphones and lower the audio for headphones while leaving the speaker volume up higher?听

Would a simple resistor work or is more required for such a modification?

Is there a place to tap into a constant audio level that is not affected by the volume control?听 Kind of like a line level output?

Thanks for your help.
--
73, W9KJO
Walter