Ion,
I managed to get my uBITX on frequency today.? Just used the MM and figured if it was 250Hz off @143000 and 1000Hz off at 166250...then I split the difference
by 3 and subtracted that from 143000 to get 135,250 (which is the magic number for my radio).
The 10 meter band is right on now according to my K3.
Now I just wish the receive would sound? a little cleaner. Are you satisfied how yours sounds? Mine seems better if I lower the IF by 250Hz (IF-250).
Also the TX output is terrible on the higher freq bands and carrier null is bad on the lower bands.
What is potentiometer RV1 for tx drive? Mine is all the way up.
Thanks for your help and being patient with me:)
73's Michael
n2zdbv
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Digital / Audio connector names?
Hi all,
having a great time with my ubitx, but in my hast to assemble with the shortest flying leads possible i was a little over enthusiastic and cut a little short. im wondering what the plugs are known as so as to order a couple of replacements.
Thanks for all the awesome info on this list!
cheers
Joel
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Re: KD8CEC firmware and basic Manager settings
#ubitx-help
Hi Nigel,
Thank you for your help!
I now have my uBITX right on frequency at 28.4 MHz using what I calculated to be the best Master Cal number...
Still have to work on the carrier null, power output on high F bands, and audio quality.
73's Michael
n2zdb
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Here are a couple of links that summarize the audio chip issues.
Putting a resistor in series with the headphone jack can protect against the chip being shorted out. In my case I put two series resistors, one for the right and one for the left channel on the headphone jack. That way I can use either mono or stereo speakers and headphones with the uBITX.
Tom, wb6b
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The BFO being too close is what I also found to be a source of too much 'carrier leakage'.? I think I was getting about 1 to 3 milliwatts leakage when the BFO was set to my liking and transmitting ssb.? .? This was after I had modified the filter by replacing the 5 100 pf capacitors with 5 82 pf capacitors. I had also modified the BITX by replacing the outputs and a few other resistor changes as have been mentioned on here.
de ku4pt
On Sat, Jul 28, 2018 at 1:49 PM, ajparent1/KB1GMX <kb1gmx@...> wrote: Usually carrier at that level may indicate the BFO needs to be set a bit further away.
The uBitx has issues with carrier leakage but usually not that bad, so check the carrier frequency first!
Joel,
While the diodes are well matched the transformer is still handmade though fairly good.
To assure balance a 50 ohm pot at the winding center tap pins 5 and 3 would help.
The RF would be on the wiper and the two wires to the ends.? Mount it under the board
with short leads.
Allison
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I do not insert or pull out any Jack plugs whilst the equipment is powered.Experience has shown that there can be a momentary short as the plug is inserted or pulled out especially problematical on audio amplifiers where the outputs may be shorted destroying
the audio chip.Ian M0IDR
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the message got jumbled up
?here is it again.
you do get pin to pin replacement.
search out for NJM 2073 8 PIN DIP
THIS HAS BEEN DEALT WITH EXTENSIVELY BY EXPERTS.
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Re: KD8CEC firmware and basic Manager settings
#ubitx-help
Once you have changed values in Memory Manager, encoded/written them back to your uBitx, you must then disconnect from the USB cable and remove power from the uBitx (turn off).
Then, power on again and after the power cycle, connect Memory Manager again and read in/decode the values - they should have changed now...
Nigel.
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Enclosed is the IRF610 datasheet.
I see no reason to claim its more robust.? It trades a 200V Drain to Source voltage for a 100V of the IRF510?
and the max current is 3.3A against the IRF510 5.6A.
FYI neither are audio transistors though you certainly use them for that.? They are high speed high current switches.
Typical use is when you want to turn on a 3A lamp on or off with very little power to the gate or switching power supply
where switching speed and low on resistance is critical to efficiency.? ?Its why the make fairly good and inexpensive
RF power amps.
Actually for the typical power dissipated usually around 5W per device in most ubitx running 10 watts out
if the heat sink is allowed good airflow (convection) will be quite adequate.? However many boxes are too
tightly closed?to allow adequate airflow.? However if you are concerned a tiny fan and some opening to
let the hot air out can make a significant difference.
The two things that kill them fast is self oscillation due to poor circuit design or layout and the resulting heat.
This is bad as often the power level is well above the TX power and the frequency is likely outside the
range of filters used.? ? The other is just long transmit sessions without adequate cooling (blocked
air flow or small heatsinks).??
Allison
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Re: Audio feedback during transmit?
#ubitx
Thanks for that. I had posted "uBitX SSB transmit oscillations on 40m only" but then noticed lesser sound from the speaker on higher frequencies. I do not know the "uBiTX memory manager" but it is time I learn.
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Usually carrier at that level may indicate the BFO needs to be set a bit further away.
The uBitx has issues with carrier leakage but usually not that bad, so check the carrier frequency first!
Joel,
While the diodes are well matched the transformer is still handmade though fairly good.
To assure balance a 50 ohm pot at the winding center tap pins 5 and 3 would help.
The RF would be on the wiper and the two wires to the ends.? Mount it under the board
with short leads.
Allison
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Michael,
The short answer is, you don't. The newer released uBitx's dont have a way to null the carrier because theoretically it's not necessary due to the diodes used in the mixers. It's near impossible to find two discrete diodes that are perfectly the same, but the SMD diodes, (I think BAT54SL),? Farhan used are two diodes in a single package that are as near the same characteristics as you can get, so eliminating the need for a null adjustment. Maybe yours are not perfect?
Joel
N6ALT
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You are missing a second, calibrated receiver on which you should be able to listen for zero beat. Try uploading Ian's firmware ( ) and you will do zero beat on your uBitx receiver using the UT beacon you can receive in your area (5, 10, or 15 MHz). To use Ian's firmware you do not need to do any hardware modifications and you will see lots of improvements. 73, Ion VA3NOI -- Ion VA3NOI
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From: [email protected] <[email protected]> On Behalf Of Joel Caulkins
Sent: 28 July 2018 17:27
To: [email protected]
Subject: Re: [BITX20] Accidental Calibrate #ubitx #calibration ? Frank,
You have inadvertently entered the Calibration Twilight Zone. I did the same thing 4 days ago and I only yesterday was able to escape. Here's what I had to do, first upgrade to KD8CEC's firmware 1.08 or later, then download version 1.04 of KD8CEC's uBitx Memory Manager and install it. Then follow this thread,? /g/BITX20/topic/kd8cec_firmware_and_basic/16637851?p=,,,20,0,0,0::recentpostdate%2Fsticky,,,20,2,0,16637851 and load the defaults mentioned there which will allow you to get control of your uBitx again, then using the memory manager continue to tweak your settings until you get it right on. I know it sounds daunting, but that's what I had to do to get back into the land of the living. As far as I'm concerned, the stock calibration procedure should be removed from the base firmware as it does more harm than good.
Joel
N6ALT
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Re: Long delivery time this time
#ubitx
Fine with me.
He's not personally fielding all inquiries from thousands of customers about shipping details.
The email address of those charged with handling such matters is? ? ? ? ?
? ? hfsignals at gmail dot com
where you supply the "at" and the "dot".
This forum will swallow attempts at posting a valid email address as a way to thwart the spambots.
Jerry
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On Sat, Jul 28, 2018 at 09:09 AM, Christopher Miller wrote:
Farhan replying to the group, better contact hfsignals, priceless.?
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Thanks Frank, also been there but getting out of it! ? Colin – M5FRA ?
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From: [email protected] <[email protected]> On Behalf Of Joel Caulkins
Sent: 28 July 2018 17:27
To: [email protected]
Subject: Re: [BITX20] Accidental Calibrate #ubitx #calibration ? Frank,
You have inadvertently entered the Calibration Twilight Zone. I did the same thing 4 days ago and I only yesterday was able to escape. Here's what I had to do, first upgrade to KD8CEC's firmware 1.08 or later, then download version 1.04 of KD8CEC's uBitx Memory Manager and install it. Then follow this thread,? /g/BITX20/topic/kd8cec_firmware_and_basic/16637851?p=,,,20,0,0,0::recentpostdate%2Fsticky,,,20,2,0,16637851 and load the defaults mentioned there which will allow you to get control of your uBitx again, then using the memory manager continue to tweak your settings until you get it right on. I know it sounds daunting, but that's what I had to do to get back into the land of the living. As far as I'm concerned, the stock calibration procedure should be removed from the base firmware as it does more harm than good.
Joel
N6ALT
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The BITX just gets better! Sorted out some snags but cannot get the Hypermite CW filter to work, will have to remove it from the case and work on it. I uploaded the latest version of the KD9CEC firmware today which is excellent. Now thinking of another BITX for the shack with a Nextion display as this one is for /P. ? Colin – M5FRA
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Hi Joel, Many thanks for sharing your frustration and the eventual solution. You are a gentleman. I shall try your solution in the hope of getting out of this Calibration Maze. I agree with your assessment of the Stock Firmware, Tune-up instructions are not much better and don't agree with the actual firmware on board the uBitx. This is a great little rig which has great potential, but lots of unnecessary grief in the Tune-Up. Many thanks again.
73,
Frank? EI8HIB
On Sat, Jul 28, 2018 at 5:27 PM, Joel Caulkins <caulktel@...> wrote: Frank,
You have inadvertently entered the Calibration Twilight Zone. I did the same thing 4 days ago and I only yesterday was able to escape. Here's what I had to do, first upgrade to KD8CEC's firmware 1.08 or later, then download version 1.04 of KD8CEC's uBitx Memory Manager and install it. Then follow this thread,? /g/BITX20/topic/kd8cec_firmware_and_basic/16637851?p=,,,20,0,0,0::recentpostdate%2Fsticky,,,20,2,0,16637851 and load the defaults mentioned there which will allow you to get control of your uBitx again, then using the memory manager continue to tweak your settings until you get it right on. I know it sounds daunting, but that's what I had to do to get back into the land of the living. As far as I'm concerned, the stock calibration procedure should be removed from the base firmware as it does more harm than good.
Joel
N6ALT
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Frank, For what it's worth, here is my struggle thread. /g/BITX20/topic/the_dreaded_lsb_and_usb_swap/23816435?p=,,,20,0,0,0::recentpostdate%2Fsticky,,,20,2,20,23816435Maybe you can glean some more info out of it. Joel N6ALT
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Bruce W4BRU
Joel Caulkins/N6ALT
Ion Petroianu, VA3NOI
Frank_EI8HIB